Vizio no pic

[Stu jaxon]

hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

 

[John-Del]

On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
> hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

 

[Stu jaxon]

On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:

On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

 

[John-Del]

On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:

On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

 

[Stu jaxon]

On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:

On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can.

 

[John-Del]

On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote:

On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:
On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON.. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color.. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can.

FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are.

I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON.

If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them.

 

[Stu jaxon]

On Tuesday, July 16, 2019 at 9:52:27 AM UTC-4, John-Del wrote:

On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote:
On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:
On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good.. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs.. i will post as soon as i can.

FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are.

I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON.

If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them.

couldn't find the fuse, no link to upload a pic.?

 

[John-Del]

On Tuesday, July 16, 2019 at 5:20:31 PM UTC-4, Stu jaxon wrote:

On Tuesday, July 16, 2019 at 9:52:27 AM UTC-4, John-Del wrote:
On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote:
On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:
On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can.

FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are.

I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON.

If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them.

couldn't find the fuse, no link to upload a pic.?

You could upload to a free hosting site (like https://imgur.com/) and post the link, or you could send them to my spam email (which I monitor): ohger1s/at/aol/dot/com

I did find a complete board kit for an E420VA in stock (same TV, smaller screen). The kit I have uses a FRC board and smaller TCON with no shield.

If you have that version, I can walk you through it. If you have the larger TCON with the large shield over the board and no FRC board, then you'll have to remove the shield on the TCON.

 

[Stu jaxon]

On Tuesday, July 16, 2019 at 6:51:04 PM UTC-4, John-Del wrote:

On Tuesday, July 16, 2019 at 5:20:31 PM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 9:52:27 AM UTC-4, John-Del wrote:
On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote:
On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:
On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights.... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can.

FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are.

I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON.

If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them.

couldn't find the fuse, no link to upload a pic.?

You could upload to a free hosting site (like https://imgur.com/) and post the link, or you could send them to my spam email (which I monitor): ohger1s/at/aol/dot/com

I did find a complete board kit for an E420VA in stock (same TV, smaller screen). The kit I have uses a FRC board and smaller TCON with no shield.

If you have that version, I can walk you through it. If you have the larger TCON with the large shield over the board and no FRC board, then you'll have to remove the shield on the TCON.

i posted it on imgur, under username...stugots77

 

[John-Del]

On Wednesday, July 17, 2019 at 11:33:12 AM UTC-4, Stu jaxon wrote:

On Tuesday, July 16, 2019 at 6:51:04 PM UTC-4, John-Del wrote:
On Tuesday, July 16, 2019 at 5:20:31 PM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 9:52:27 AM UTC-4, John-Del wrote:
On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote:
On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:
On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can.

FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are.

I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON.

If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them.

couldn't find the fuse, no link to upload a pic.?

You could upload to a free hosting site (like https://imgur.com/) and post the link, or you could send them to my spam email (which I monitor): ohger1s/at/aol/dot/com

I did find a complete board kit for an E420VA in stock (same TV, smaller screen). The kit I have uses a FRC board and smaller TCON with no shield..

If you have that version, I can walk you through it. If you have the larger TCON with the large shield over the board and no FRC board, then you'll have to remove the shield on the TCON.

i posted it on imgur, under username...stugots77

Not found by name.

Open the picture you posted, then cut/paste the URL of the actual picture.

 

[Stu jaxon]

On Wednesday, July 17, 2019 at 12:15:04 PM UTC-4, John-Del wrote:

On Wednesday, July 17, 2019 at 11:33:12 AM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 6:51:04 PM UTC-4, John-Del wrote:
On Tuesday, July 16, 2019 at 5:20:31 PM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 9:52:27 AM UTC-4, John-Del wrote:
On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote:
On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:
On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main..

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1..2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can.

FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are.

I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON.

If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them.

couldn't find the fuse, no link to upload a pic.?

You could upload to a free hosting site (like https://imgur.com/) and post the link, or you could send them to my spam email (which I monitor): ohger1s/at/aol/dot/com

I did find a complete board kit for an E420VA in stock (same TV, smaller screen). The kit I have uses a FRC board and smaller TCON with no shield.

If you have that version, I can walk you through it. If you have the larger TCON with the large shield over the board and no FRC board, then you'll have to remove the shield on the TCON.

i posted it on imgur, under username...stugots77

Not found by name.

Open the picture you posted, then cut/paste the URL of the actual picture..

ok,.. https://imgur.com/hitZFrn

 

[John-Del]

On Wednesday, July 17, 2019 at 1:44:41 PM UTC-4, Stu jaxon wrote:

On Wednesday, July 17, 2019 at 12:15:04 PM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 11:33:12 AM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 6:51:04 PM UTC-4, John-Del wrote:
On Tuesday, July 16, 2019 at 5:20:31 PM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 9:52:27 AM UTC-4, John-Del wrote:
On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote:
On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:
On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse..

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can.

FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are.

I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON.

If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them.

couldn't find the fuse, no link to upload a pic.?

You could upload to a free hosting site (like https://imgur.com/) and post the link, or you could send them to my spam email (which I monitor): ohger1s/at/aol/dot/com

I did find a complete board kit for an E420VA in stock (same TV, smaller screen). The kit I have uses a FRC board and smaller TCON with no shield.

If you have that version, I can walk you through it. If you have the larger TCON with the large shield over the board and no FRC board, then you'll have to remove the shield on the TCON.

i posted it on imgur, under username...stugots77

Not found by name.

Open the picture you posted, then cut/paste the URL of the actual picture.


ok,.. https://imgur.com/hitZFrn

That's the bigger TCON with the FRC board built in.

That FB near the LVDS connector on the TCON should have 12V on both sides of it when the TV is on. If the 12V is missing, unplug the LVDS and check that FB to ground for resistance. Should read no less than 10K ohms to ground. If the resistance on that FB is showing low ohms, the TCON has a shorted component on it.

U4403 should have something like 1.2V on the tab. If it doesn't, check the input pin for 3.3. That series of tab regulator is a common problem on main boards,FRC boards, and TCONs.

U4402 and u4407 should have something like 3.3 on one, and 1.8 volts on the other (typical Vizio reg voltages) measured at the tabs.

If those voltages are missing, check voltages on CN4402. There should be 12V and 5V on that connector. If either/both are missing, check for shorts to ground as you did with the ferrite bead. If there are no shorts and no voltages, I'd suspect the main.

If the 12 and 5 volt inputs are there on the connector, and the 12 volts is on the ferrite bead, and you can view differential activity on the LVDS connector with a scope, and you can't get a half picture with either display ribbon removed, indications are very strong towards the TCON/FRC board.

 

[Stu jaxon]

On Wednesday, July 17, 2019 at 3:02:02 PM UTC-4, John-Del wrote:

On Wednesday, July 17, 2019 at 1:44:41 PM UTC-4, Stu jaxon wrote:
On Wednesday, July 17, 2019 at 12:15:04 PM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 11:33:12 AM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 6:51:04 PM UTC-4, John-Del wrote:
On Tuesday, July 16, 2019 at 5:20:31 PM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 9:52:27 AM UTC-4, John-Del wrote:
On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote:
On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:
On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan....

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display.. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can.

FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are.

I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON.

If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them.

couldn't find the fuse, no link to upload a pic.?

You could upload to a free hosting site (like https://imgur.com/) and post the link, or you could send them to my spam email (which I monitor): ohger1s/at/aol/dot/com

I did find a complete board kit for an E420VA in stock (same TV, smaller screen). The kit I have uses a FRC board and smaller TCON with no shield.

If you have that version, I can walk you through it. If you have the larger TCON with the large shield over the board and no FRC board, then you'll have to remove the shield on the TCON.

i posted it on imgur, under username...stugots77

Not found by name.

Open the picture you posted, then cut/paste the URL of the actual picture.


ok,.. https://imgur.com/hitZFrn

That's the bigger TCON with the FRC board built in.

That FB near the LVDS connector on the TCON should have 12V on both sides of it when the TV is on. If the 12V is missing, unplug the LVDS and check that FB to ground for resistance. Should read no less than 10K ohms to ground. If the resistance on that FB is showing low ohms, the TCON has a shorted component on it.

U4403 should have something like 1.2V on the tab. If it doesn't, check the input pin for 3.3. That series of tab regulator is a common problem on main boards,FRC boards, and TCONs.

U4402 and u4407 should have something like 3.3 on one, and 1.8 volts on the other (typical Vizio reg voltages) measured at the tabs.

If those voltages are missing, check voltages on CN4402. There should be 12V and 5V on that connector. If either/both are missing, check for shorts to ground as you did with the ferrite bead. If there are no shorts and no voltages, I'd suspect the main.

If the 12 and 5 volt inputs are there on the connector, and the 12 volts is on the ferrite bead, and you can view differential activity on the LVDS connector with a scope, and you can't get a half picture with either display ribbon removed, indications are very strong towards the TCON/FRC board.

wow, you are a genius, with tv on, no 12v on either side of fb, with lvds disconnected, i got zero ohms, so it's a bad tcon board, that's shorted.. ?

 

[John-Del]

On Wednesday, July 17, 2019 at 8:11:46 PM UTC-4, Stu jaxon wrote:

On Wednesday, July 17, 2019 at 3:02:02 PM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 1:44:41 PM UTC-4, Stu jaxon wrote:
On Wednesday, July 17, 2019 at 12:15:04 PM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 11:33:12 AM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 6:51:04 PM UTC-4, John-Del wrote:
On Tuesday, July 16, 2019 at 5:20:31 PM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 9:52:27 AM UTC-4, John-Del wrote:
On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote:
On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:
On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan....

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can.

FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are.

I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON.

If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them.

couldn't find the fuse, no link to upload a pic.?

You could upload to a free hosting site (like https://imgur.com/) and post the link, or you could send them to my spam email (which I monitor): ohger1s/at/aol/dot/com

I did find a complete board kit for an E420VA in stock (same TV, smaller screen). The kit I have uses a FRC board and smaller TCON with no shield.

If you have that version, I can walk you through it. If you have the larger TCON with the large shield over the board and no FRC board, then you'll have to remove the shield on the TCON.

i posted it on imgur, under username...stugots77

Not found by name.

Open the picture you posted, then cut/paste the URL of the actual picture.


ok,.. https://imgur.com/hitZFrn

That's the bigger TCON with the FRC board built in.

That FB near the LVDS connector on the TCON should have 12V on both sides of it when the TV is on. If the 12V is missing, unplug the LVDS and check that FB to ground for resistance. Should read no less than 10K ohms to ground. If the resistance on that FB is showing low ohms, the TCON has a shorted component on it.

U4403 should have something like 1.2V on the tab. If it doesn't, check the input pin for 3.3. That series of tab regulator is a common problem on main boards,FRC boards, and TCONs.

U4402 and u4407 should have something like 3.3 on one, and 1.8 volts on the other (typical Vizio reg voltages) measured at the tabs.

If those voltages are missing, check voltages on CN4402. There should be 12V and 5V on that connector. If either/both are missing, check for shorts to ground as you did with the ferrite bead. If there are no shorts and no voltages, I'd suspect the main.

If the 12 and 5 volt inputs are there on the connector, and the 12 volts is on the ferrite bead, and you can view differential activity on the LVDS connector with a scope, and you can't get a half picture with either display ribbon removed, indications are very strong towards the TCON/FRC board.

with tv on, no 12v on either side of fb, with lvds disconnected, i got zero ohms, so it's a bad tcon board, that's shorted.. ?

With the LVDS harness disconnected, run the TV one more time and make sure you have 12V on the harness. Most of the time, a shorted TCON will cause the 12V supply that feeds it to shut down, but there's a chance the 12V source could have been damaged as well. If there's no 12V, check the main for an open surface mount fuse (these are generally white on Vizios with a letter on them).

If you get 12V on the disconnected LVDS connector, then just a TCON should get you going. If you have the time, you can check for shorted chip caps. These are brown, about the size of that ferrite bead, and have no markings.. One way is to feed a current regulated supply set to 2 amps right at that ferrite bead to force feed the TCON to see what gets hot. A frost covering from a can of freeze spray will often give you a visual of what's drawing the current (whatever thaws first).

 

[Stu jaxon]

On Thursday, July 18, 2019 at 7:14:06 AM UTC-4, John-Del wrote:

On Wednesday, July 17, 2019 at 8:11:46 PM UTC-4, Stu jaxon wrote:
On Wednesday, July 17, 2019 at 3:02:02 PM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 1:44:41 PM UTC-4, Stu jaxon wrote:
On Wednesday, July 17, 2019 at 12:15:04 PM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 11:33:12 AM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 6:51:04 PM UTC-4, John-Del wrote:
On Tuesday, July 16, 2019 at 5:20:31 PM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 9:52:27 AM UTC-4, John-Del wrote:
On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote:
On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:
On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model...E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can.

FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are.

I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON.

If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them.

couldn't find the fuse, no link to upload a pic.?

You could upload to a free hosting site (like https://imgur.com/) and post the link, or you could send them to my spam email (which I monitor): ohger1s/at/aol/dot/com

I did find a complete board kit for an E420VA in stock (same TV, smaller screen). The kit I have uses a FRC board and smaller TCON with no shield.

If you have that version, I can walk you through it. If you have the larger TCON with the large shield over the board and no FRC board, then you'll have to remove the shield on the TCON.

i posted it on imgur, under username...stugots77

Not found by name.

Open the picture you posted, then cut/paste the URL of the actual picture.


ok,.. https://imgur.com/hitZFrn

That's the bigger TCON with the FRC board built in.

That FB near the LVDS connector on the TCON should have 12V on both sides of it when the TV is on. If the 12V is missing, unplug the LVDS and check that FB to ground for resistance. Should read no less than 10K ohms to ground. If the resistance on that FB is showing low ohms, the TCON has a shorted component on it.

U4403 should have something like 1.2V on the tab. If it doesn't, check the input pin for 3.3. That series of tab regulator is a common problem on main boards,FRC boards, and TCONs.

U4402 and u4407 should have something like 3.3 on one, and 1.8 volts on the other (typical Vizio reg voltages) measured at the tabs.

If those voltages are missing, check voltages on CN4402. There should be 12V and 5V on that connector. If either/both are missing, check for shorts to ground as you did with the ferrite bead. If there are no shorts and no voltages, I'd suspect the main.

If the 12 and 5 volt inputs are there on the connector, and the 12 volts is on the ferrite bead, and you can view differential activity on the LVDS connector with a scope, and you can't get a half picture with either display ribbon removed, indications are very strong towards the TCON/FRC board.



with tv on, no 12v on either side of fb, with lvds disconnected, i got zero ohms, so it's a bad tcon board, that's shorted.. ?

With the LVDS harness disconnected, run the TV one more time and make sure you have 12V on the harness. Most of the time, a shorted TCON will cause the 12V supply that feeds it to shut down, but there's a chance the 12V source could have been damaged as well. If there's no 12V, check the main for an open surface mount fuse (these are generally white on Vizios with a letter on them).

If you get 12V on the disconnected LVDS connector, then just a TCON should get you going. If you have the time, you can check for shorted chip caps.. These are brown, about the size of that ferrite bead, and have no markings. One way is to feed a current regulated supply set to 2 amps right at that ferrite bead to force feed the TCON to see what gets hot. A frost covering from a can of freeze spray will often give you a visual of what's drawing the current (whatever thaws first).

if your talking about the harness connector cn702, I get 11.97v on green wire, 11.98 v on the yellow wire. nothing on the red and orange wires. 5v on brown wire. and just for your info I got a little anxious and ordered the tcon board arrive yesterday, got nothing no pic... the main board is recently purchased also from ebay .. I think i got both from electroparts..

 

[John-Del]

On Friday, July 19, 2019 at 9:06:08 AM UTC-4, Stu jaxon wrote:

On Thursday, July 18, 2019 at 7:14:06 AM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 8:11:46 PM UTC-4, Stu jaxon wrote:
On Wednesday, July 17, 2019 at 3:02:02 PM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 1:44:41 PM UTC-4, Stu jaxon wrote:
On Wednesday, July 17, 2019 at 12:15:04 PM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 11:33:12 AM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 6:51:04 PM UTC-4, John-Del wrote:
On Tuesday, July 16, 2019 at 5:20:31 PM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 9:52:27 AM UTC-4, John-Del wrote:
On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote:
On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:
On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can.

FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are.

I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON.

If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them.

couldn't find the fuse, no link to upload a pic.?

You could upload to a free hosting site (like https://imgur..com/) and post the link, or you could send them to my spam email (which I monitor): ohger1s/at/aol/dot/com

I did find a complete board kit for an E420VA in stock (same TV, smaller screen). The kit I have uses a FRC board and smaller TCON with no shield.

If you have that version, I can walk you through it. If you have the larger TCON with the large shield over the board and no FRC board, then you'll have to remove the shield on the TCON.

i posted it on imgur, under username...stugots77

Not found by name.

Open the picture you posted, then cut/paste the URL of the actual picture.


ok,.. https://imgur.com/hitZFrn

That's the bigger TCON with the FRC board built in.

That FB near the LVDS connector on the TCON should have 12V on both sides of it when the TV is on. If the 12V is missing, unplug the LVDS and check that FB to ground for resistance. Should read no less than 10K ohms to ground. If the resistance on that FB is showing low ohms, the TCON has a shorted component on it.

U4403 should have something like 1.2V on the tab. If it doesn't, check the input pin for 3.3. That series of tab regulator is a common problem on main boards,FRC boards, and TCONs.

U4402 and u4407 should have something like 3.3 on one, and 1.8 volts on the other (typical Vizio reg voltages) measured at the tabs.

If those voltages are missing, check voltages on CN4402. There should be 12V and 5V on that connector. If either/both are missing, check for shorts to ground as you did with the ferrite bead. If there are no shorts and no voltages, I'd suspect the main.

If the 12 and 5 volt inputs are there on the connector, and the 12 volts is on the ferrite bead, and you can view differential activity on the LVDS connector with a scope, and you can't get a half picture with either display ribbon removed, indications are very strong towards the TCON/FRC board.



with tv on, no 12v on either side of fb, with lvds disconnected, i got zero ohms, so it's a bad tcon board, that's shorted.. ?

With the LVDS harness disconnected, run the TV one more time and make sure you have 12V on the harness. Most of the time, a shorted TCON will cause the 12V supply that feeds it to shut down, but there's a chance the 12V source could have been damaged as well. If there's no 12V, check the main for an open surface mount fuse (these are generally white on Vizios with a letter on them).

If you get 12V on the disconnected LVDS connector, then just a TCON should get you going. If you have the time, you can check for shorted chip caps. These are brown, about the size of that ferrite bead, and have no markings. One way is to feed a current regulated supply set to 2 amps right at that ferrite bead to force feed the TCON to see what gets hot. A frost covering from a can of freeze spray will often give you a visual of what's drawing the current (whatever thaws first).

if your talking about the harness connector cn702, I get 11.97v on green wire, 11.98 v on the yellow wire. nothing on the red and orange wires. 5v on brown wire. and just for your info I got a little anxious and ordered the tcon board arrive yesterday, got nothing no pic... the main board is recently purchased also from ebay .. I think i got both from electroparts..

Did you try your original main board back in with the new TCON? You may have added a problem where none existed before.

There are two 12V inputs going to that TCON/FRC board. The CN702 four wire connector (which will have 12V , 5V, and ground) and the larger LVDS harness CN4404 where the ferrite bead smd component is.

So on CN 702, you have the 12V and 5V, so that's OK.

On the ferrite bead near the LVDS, you should have 12v as well. I don't know if they're sourced from the same 12V supply or not, but you should have 12V on that ferrite bead. Your earlier post said you did not have 12V on that ferrite bead and were reading a short to ground. Is this correct? If you unplug the LVDS harness, the short on the ferrite bead to the TCON ground will either go away or remain. If it goes away, the problem is on the main. If it stays, the short is on the TCON.

Be aware that fair percentage of boards bought on-line are defective regardless of where they're purchased. There are no new parts available for these, so any part you buy is from a recycled donor, and none of these mass parts sellers check them. They strip the carcass of it's boards, sell them, and replace or refund the money if they get a complaint. If the donor TV failed with the same defective board you have, you'll have the same issue.

This is why we go through several tests before estimating the job for the customer, and why we repair about 95 percent of the boards we see.

There are several guys in our association that sell parts on ebay, but these guys are technicians who will only sell verified boards.

The good news is that Electroparts is a good company and they'll replace or refund without question.

 

[Stu jaxon]

On Friday, July 19, 2019 at 10:18:29 AM UTC-4, John-Del wrote:

On Friday, July 19, 2019 at 9:06:08 AM UTC-4, Stu jaxon wrote:
On Thursday, July 18, 2019 at 7:14:06 AM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 8:11:46 PM UTC-4, Stu jaxon wrote:
On Wednesday, July 17, 2019 at 3:02:02 PM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 1:44:41 PM UTC-4, Stu jaxon wrote:
On Wednesday, July 17, 2019 at 12:15:04 PM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 11:33:12 AM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 6:51:04 PM UTC-4, John-Del wrote:
On Tuesday, July 16, 2019 at 5:20:31 PM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 9:52:27 AM UTC-4, John-Del wrote:
On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote:
On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:
On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can.

FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are.

I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON.

If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them.

couldn't find the fuse, no link to upload a pic.?

You could upload to a free hosting site (like https://imgur.com/) and post the link, or you could send them to my spam email (which I monitor): ohger1s/at/aol/dot/com

I did find a complete board kit for an E420VA in stock (same TV, smaller screen). The kit I have uses a FRC board and smaller TCON with no shield.

If you have that version, I can walk you through it. If you have the larger TCON with the large shield over the board and no FRC board, then you'll have to remove the shield on the TCON.

i posted it on imgur, under username...stugots77

Not found by name.

Open the picture you posted, then cut/paste the URL of the actual picture.


ok,.. https://imgur.com/hitZFrn

That's the bigger TCON with the FRC board built in.

That FB near the LVDS connector on the TCON should have 12V on both sides of it when the TV is on. If the 12V is missing, unplug the LVDS and check that FB to ground for resistance. Should read no less than 10K ohms to ground. If the resistance on that FB is showing low ohms, the TCON has a shorted component on it.

U4403 should have something like 1.2V on the tab. If it doesn't, check the input pin for 3.3. That series of tab regulator is a common problem on main boards,FRC boards, and TCONs.

U4402 and u4407 should have something like 3.3 on one, and 1.8 volts on the other (typical Vizio reg voltages) measured at the tabs.

If those voltages are missing, check voltages on CN4402. There should be 12V and 5V on that connector. If either/both are missing, check for shorts to ground as you did with the ferrite bead. If there are no shorts and no voltages, I'd suspect the main.

If the 12 and 5 volt inputs are there on the connector, and the 12 volts is on the ferrite bead, and you can view differential activity on the LVDS connector with a scope, and you can't get a half picture with either display ribbon removed, indications are very strong towards the TCON/FRC board.



with tv on, no 12v on either side of fb, with lvds disconnected, i got zero ohms, so it's a bad tcon board, that's shorted.. ?

With the LVDS harness disconnected, run the TV one more time and make sure you have 12V on the harness. Most of the time, a shorted TCON will cause the 12V supply that feeds it to shut down, but there's a chance the 12V source could have been damaged as well. If there's no 12V, check the main for an open surface mount fuse (these are generally white on Vizios with a letter on them).

If you get 12V on the disconnected LVDS connector, then just a TCON should get you going. If you have the time, you can check for shorted chip caps. These are brown, about the size of that ferrite bead, and have no markings. One way is to feed a current regulated supply set to 2 amps right at that ferrite bead to force feed the TCON to see what gets hot. A frost covering from a can of freeze spray will often give you a visual of what's drawing the current (whatever thaws first).

if your talking about the harness connector cn702, I get 11.97v on green wire, 11.98 v on the yellow wire. nothing on the red and orange wires. 5v on brown wire. and just for your info I got a little anxious and ordered the tcon board arrive yesterday, got nothing no pic... the main board is recently purchased also from ebay .. I think i got both from electroparts..


Did you try your original main board back in with the new TCON? You may have added a problem where none existed before.

There are two 12V inputs going to that TCON/FRC board. The CN702 four wire connector (which will have 12V , 5V, and ground) and the larger LVDS harness CN4404 where the ferrite bead smd component is.

So on CN 702, you have the 12V and 5V, so that's OK.

On the ferrite bead near the LVDS, you should have 12v as well. I don't know if they're sourced from the same 12V supply or not, but you should have 12V on that ferrite bead. Your earlier post said you did not have 12V on that ferrite bead and were reading a short to ground. Is this correct? If you unplug the LVDS harness, the short on the ferrite bead to the TCON ground will either go away or remain. If it goes away, the problem is on the main. If it stays, the short is on the TCON.

Be aware that fair percentage of boards bought on-line are defective regardless of where they're purchased. There are no new parts available for these, so any part you buy is from a recycled donor, and none of these mass parts sellers check them. They strip the carcass of it's boards, sell them, and replace or refund the money if they get a complaint. If the donor TV failed with the same defective board you have, you'll have the same issue.

This is why we go through several tests before estimating the job for the customer, and why we repair about 95 percent of the boards we see.

There are several guys in our association that sell parts on ebay, but these guys are technicians who will only sell verified boards.

The good news is that Electroparts is a good company and they'll replace or refund without question.

the short is still there, with the lvds cable removed. just bought the tcon board.? I now noticed that the backlights go off off after a minute or two, high voltage shut down..? I put the original main board back in, and got two 12v & 5v inputs to the tcon on cn702..

 

[John-Del]

On Friday, July 19, 2019 at 6:05:31 PM UTC-4, Stu jaxon wrote:

On Friday, July 19, 2019 at 10:18:29 AM UTC-4, John-Del wrote:
On Friday, July 19, 2019 at 9:06:08 AM UTC-4, Stu jaxon wrote:
On Thursday, July 18, 2019 at 7:14:06 AM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 8:11:46 PM UTC-4, Stu jaxon wrote:
On Wednesday, July 17, 2019 at 3:02:02 PM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 1:44:41 PM UTC-4, Stu jaxon wrote:
On Wednesday, July 17, 2019 at 12:15:04 PM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 11:33:12 AM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 6:51:04 PM UTC-4, John-Del wrote:
On Tuesday, July 16, 2019 at 5:20:31 PM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 9:52:27 AM UTC-4, John-Del wrote:
On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote:
On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:
On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada... when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard.. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good.. I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board...?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can.

FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are.

I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON.

If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them.

couldn't find the fuse, no link to upload a pic.?

You could upload to a free hosting site (like https://imgur.com/) and post the link, or you could send them to my spam email (which I monitor): ohger1s/at/aol/dot/com

I did find a complete board kit for an E420VA in stock (same TV, smaller screen). The kit I have uses a FRC board and smaller TCON with no shield.

If you have that version, I can walk you through it. If you have the larger TCON with the large shield over the board and no FRC board, then you'll have to remove the shield on the TCON.

i posted it on imgur, under username...stugots77

Not found by name.

Open the picture you posted, then cut/paste the URL of the actual picture.


ok,.. https://imgur.com/hitZFrn

That's the bigger TCON with the FRC board built in.

That FB near the LVDS connector on the TCON should have 12V on both sides of it when the TV is on. If the 12V is missing, unplug the LVDS and check that FB to ground for resistance. Should read no less than 10K ohms to ground. If the resistance on that FB is showing low ohms, the TCON has a shorted component on it.

U4403 should have something like 1.2V on the tab. If it doesn't, check the input pin for 3.3. That series of tab regulator is a common problem on main boards,FRC boards, and TCONs.

U4402 and u4407 should have something like 3.3 on one, and 1.8 volts on the other (typical Vizio reg voltages) measured at the tabs.

If those voltages are missing, check voltages on CN4402. There should be 12V and 5V on that connector. If either/both are missing, check for shorts to ground as you did with the ferrite bead. If there are no shorts and no voltages, I'd suspect the main.

If the 12 and 5 volt inputs are there on the connector, and the 12 volts is on the ferrite bead, and you can view differential activity on the LVDS connector with a scope, and you can't get a half picture with either display ribbon removed, indications are very strong towards the TCON/FRC board.



with tv on, no 12v on either side of fb, with lvds disconnected, i got zero ohms, so it's a bad tcon board, that's shorted.. ?

With the LVDS harness disconnected, run the TV one more time and make sure you have 12V on the harness. Most of the time, a shorted TCON will cause the 12V supply that feeds it to shut down, but there's a chance the 12V source could have been damaged as well. If there's no 12V, check the main for an open surface mount fuse (these are generally white on Vizios with a letter on them).

If you get 12V on the disconnected LVDS connector, then just a TCON should get you going. If you have the time, you can check for shorted chip caps. These are brown, about the size of that ferrite bead, and have no markings. One way is to feed a current regulated supply set to 2 amps right at that ferrite bead to force feed the TCON to see what gets hot. A frost covering from a can of freeze spray will often give you a visual of what's drawing the current (whatever thaws first).

if your talking about the harness connector cn702, I get 11.97v on green wire, 11.98 v on the yellow wire. nothing on the red and orange wires. 5v on brown wire. and just for your info I got a little anxious and ordered the tcon board arrive yesterday, got nothing no pic... the main board is recently purchased also from ebay .. I think i got both from electroparts..


Did you try your original main board back in with the new TCON? You may have added a problem where none existed before.

There are two 12V inputs going to that TCON/FRC board. The CN702 four wire connector (which will have 12V , 5V, and ground) and the larger LVDS harness CN4404 where the ferrite bead smd component is.

So on CN 702, you have the 12V and 5V, so that's OK.

On the ferrite bead near the LVDS, you should have 12v as well. I don't know if they're sourced from the same 12V supply or not, but you should have 12V on that ferrite bead. Your earlier post said you did not have 12V on that ferrite bead and were reading a short to ground. Is this correct? If you unplug the LVDS harness, the short on the ferrite bead to the TCON ground will either go away or remain. If it goes away, the problem is on the main. If it stays, the short is on the TCON.

Be aware that fair percentage of boards bought on-line are defective regardless of where they're purchased. There are no new parts available for these, so any part you buy is from a recycled donor, and none of these mass parts sellers check them. They strip the carcass of it's boards, sell them, and replace or refund the money if they get a complaint. If the donor TV failed with the same defective board you have, you'll have the same issue.

This is why we go through several tests before estimating the job for the customer, and why we repair about 95 percent of the boards we see.

There are several guys in our association that sell parts on ebay, but these guys are technicians who will only sell verified boards.

The good news is that Electroparts is a good company and they'll replace or refund without question.

the short is still there, with the lvds cable removed. just bought the tcon board.?

You're confusing me. Are you saying that both the original TCON board and the one you just bought are showing a low ohm short to ground as read on that ferrite bead near the LVDS cable?


>I put the original main board back in, and got two 12v & 5v inputs to the tcon on cn702..

Again, see if there is any 12DC voltage on the LVDS connector when it is disconnected from the TCON. IIRC, the CN702 connector goes to the power supply, not the main. Is there 12V on the LVDS connector when it is lifted off the TCON?

 

[Stu jaxon]

On Friday, July 19, 2019 at 8:19:59 PM UTC-4, John-Del wrote:

On Friday, July 19, 2019 at 6:05:31 PM UTC-4, Stu jaxon wrote:
On Friday, July 19, 2019 at 10:18:29 AM UTC-4, John-Del wrote:
On Friday, July 19, 2019 at 9:06:08 AM UTC-4, Stu jaxon wrote:
On Thursday, July 18, 2019 at 7:14:06 AM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 8:11:46 PM UTC-4, Stu jaxon wrote:
On Wednesday, July 17, 2019 at 3:02:02 PM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 1:44:41 PM UTC-4, Stu jaxon wrote:
On Wednesday, July 17, 2019 at 12:15:04 PM UTC-4, John-Del wrote:
On Wednesday, July 17, 2019 at 11:33:12 AM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 6:51:04 PM UTC-4, John-Del wrote:
On Tuesday, July 16, 2019 at 5:20:31 PM UTC-4, Stu jaxon wrote:
On Tuesday, July 16, 2019 at 9:52:27 AM UTC-4, John-Del wrote:
On Monday, July 15, 2019 at 9:07:58 PM UTC-4, Stu jaxon wrote:
On Sunday, July 14, 2019 at 9:14:22 AM UTC-4, John-Del wrote:
On Saturday, July 13, 2019 at 8:14:28 PM UTC-4, Stu jaxon wrote:
On Saturday, July 13, 2019 at 7:01:56 AM UTC-4, John-Del wrote:
On Friday, July 12, 2019 at 4:39:38 PM UTC-4, Stu jaxon wrote:
hi group, i'm working on a Vizio 39 Tesla model..E470va, so it's a 47 inch, I have no picture no audio, I do get the correct voltages from the power supply, I changed the main board, and nada.. when I turn the tv on, with the back cover off, I see a led ON THE INVERTER BOARD turn blue twice then turns off, I am suspecting the tcon board or also called this TQAPT5K00901 TQAPT 5k009 01 LCD PC Board Unit Motherboard. this is a lcd tv, I do have backlights, and a faint glow on the screen from the backlights... any help on this problem, will be taken seriously. Thanks,Stan...

The blue LED on the inverter board will light and extinguish if the inverters are normal.

You could have a bad TCON, a bad display, or still have a bad main. There are no new parts available for these, so any board you buy from *any* supplier is suspect. A legitimate ebay seller who sells a board from a TV with a cracked screen but otherwise verifiable as fully functional is a fair bet, but we still don't know if the donor had a picture, even if it did also have a cracked screen. Other internet board sellers are just recyclers who sell boards without testing, but they offer generous return policies and long warranties.

The way I approach a no-picture issue (with normal backlights) is to scope the differential signals coming out of the main at the LVDS plug to the TCON. These are digital signals and are jibberish, but if they're there, the main is usually good. While scoping, it's helpful to push the TVs menu button and watch for any activity on the differential outputs. If only DC appears on the LVDS output connector, you still have a bad main.

If the differential signals are there, try removing either of the two ribbon connectors going to the display from the TCON and see if you get half a pix. If not, reconnect the ribbon and remove the other. If you get half a picture from either attempt, you've got a bad display. Still no pic? Prob bad TCON.

There is a 12V fuse near the power harness you can check, but if it's open, usually a bad multi layer chip cap has shorted although there could also be a bad IC. If the fuse is good, you can check for DC at various points on the board if marked. If nothing is marked, look for small round inductors that identify the handful of buck converters that normally populate TCONs. There should be DC voltages on them and can vary from 1.2 to 24V depending on design. If any are missing with the output ribbons disconnected, you have a bad TCON.

thanks for the info.. the fuse tested good... I hooked up a scope 5v ch1, on dc coupling I got dc differential signals with the menu button pressed on some pins and not data on others same results with ac coupling, if the tcon board was good was i supposed to see an AC siganl.? and with the ribbons removed no pic on either side.. bad tcon board..?

I should have asked if you checked for 12V on the TCON fuse.

With the scope on AC coupling, set it for 50mv with a 10X probe and maybe .5ms for the horizontal - neither setting is critical. The signals are digital data and not on every pin. What I've found over the years is that any data visible with a known good input source or menu activation (which guarantees *something* should appear on the screen) means the main is good. Of course, those that produce a picture with issues like off colors, pixelization, gamma errors etc. could be the main and it's nearly impossible to tell if the main or the TCON are causing those problems by scoping the signals. But generally, if you have differential signals to the TCON but no picture, the main is good.

So if you have 12V on the TCON fuse, it sounds like you have a bad TCON. Pull the shield off and look for any shorted multi layer capacitors. These are small SMD caps, have no markings, and are invariably brown in color. The ones most suspect are the ones that are side by side in a parallel arrangement. If one of these caps short, the buck regulator in the circuit will shut down. The problem is that one shorted cap may be paralleled by several and up to a dozen, so picking the offending shorted cap out can take some time.

I can check Monday to see if I have a verified good TCON in the shop.

if fb401 is a fuse, there is no voltage on either side. i didn't get a chance to further test/scope the tcon board, my truck is in need of repairs. i will post as soon as i can.

FB nomenclature devices generally are ferrite beads, although they're shaped like any other SMD resistor or capacitor. They tend to be gray in color, have no markings, and should read zero ohms. They may or may not have voltage on them depending on where in the circuit they are.

I just ran your model number through Shop Jimmy to see what the board looks like, and it appears there are two different versions of that TV depending on the display installed. One version has the main board connected directly to the TCON, the other has the main board connected to an FRC board which then feeds the TCON. Both versions use a different TCON.

If you have the smaller TCON, there is a white ceramic surface mount fuse marked 3A which should have 12V on it. You will also have the FRC board which is an equal possibility as the TCON board for causing no pix.

If you have the larger TCON, there is a shield over it that covers most of the components and I'll need to see a picture of the board without the shield to point out the fuse. Follow the leads from connector CN4402 under the shield and you should find the fuse. It might be ceramic like the other one or look like a smd resistor. Most non-ceramic fuses used in these types of boards have a single letter on them indicating current. The larger white ceramic ones have the actual current printed numerically on them.

couldn't find the fuse, no link to upload a pic.?

You could upload to a free hosting site (like https://imgur.com/) and post the link, or you could send them to my spam email (which I monitor): ohger1s/at/aol/dot/com

I did find a complete board kit for an E420VA in stock (same TV, smaller screen). The kit I have uses a FRC board and smaller TCON with no shield.

If you have that version, I can walk you through it. If you have the larger TCON with the large shield over the board and no FRC board, then you'll have to remove the shield on the TCON.

i posted it on imgur, under username...stugots77

Not found by name.

Open the picture you posted, then cut/paste the URL of the actual picture.


ok,.. https://imgur.com/hitZFrn

That's the bigger TCON with the FRC board built in.

That FB near the LVDS connector on the TCON should have 12V on both sides of it when the TV is on. If the 12V is missing, unplug the LVDS and check that FB to ground for resistance. Should read no less than 10K ohms to ground. If the resistance on that FB is showing low ohms, the TCON has a shorted component on it.

U4403 should have something like 1.2V on the tab. If it doesn't, check the input pin for 3.3. That series of tab regulator is a common problem on main boards,FRC boards, and TCONs.

U4402 and u4407 should have something like 3.3 on one, and 1.8 volts on the other (typical Vizio reg voltages) measured at the tabs.

If those voltages are missing, check voltages on CN4402. There should be 12V and 5V on that connector. If either/both are missing, check for shorts to ground as you did with the ferrite bead. If there are no shorts and no voltages, I'd suspect the main.

If the 12 and 5 volt inputs are there on the connector, and the 12 volts is on the ferrite bead, and you can view differential activity on the LVDS connector with a scope, and you can't get a half picture with either display ribbon removed, indications are very strong towards the TCON/FRC board.



with tv on, no 12v on either side of fb, with lvds disconnected, i got zero ohms, so it's a bad tcon board, that's shorted.. ?

With the LVDS harness disconnected, run the TV one more time and make sure you have 12V on the harness. Most of the time, a shorted TCON will cause the 12V supply that feeds it to shut down, but there's a chance the 12V source could have been damaged as well. If there's no 12V, check the main for an open surface mount fuse (these are generally white on Vizios with a letter on them).

If you get 12V on the disconnected LVDS connector, then just a TCON should get you going. If you have the time, you can check for shorted chip caps. These are brown, about the size of that ferrite bead, and have no markings. One way is to feed a current regulated supply set to 2 amps right at that ferrite bead to force feed the TCON to see what gets hot. A frost covering from a can of freeze spray will often give you a visual of what's drawing the current (whatever thaws first).

if your talking about the harness connector cn702, I get 11.97v on green wire, 11.98 v on the yellow wire. nothing on the red and orange wires.. 5v on brown wire. and just for your info I got a little anxious and ordered the tcon board arrive yesterday, got nothing no pic... the main board is recently purchased also from ebay .. I think i got both from electroparts...


Did you try your original main board back in with the new TCON? You may have added a problem where none existed before.

There are two 12V inputs going to that TCON/FRC board. The CN702 four wire connector (which will have 12V , 5V, and ground) and the larger LVDS harness CN4404 where the ferrite bead smd component is.

So on CN 702, you have the 12V and 5V, so that's OK.

On the ferrite bead near the LVDS, you should have 12v as well. I don't know if they're sourced from the same 12V supply or not, but you should have 12V on that ferrite bead. Your earlier post said you did not have 12V on that ferrite bead and were reading a short to ground. Is this correct? If you unplug the LVDS harness, the short on the ferrite bead to the TCON ground will either go away or remain. If it goes away, the problem is on the main. If it stays, the short is on the TCON.

Be aware that fair percentage of boards bought on-line are defective regardless of where they're purchased. There are no new parts available for these, so any part you buy is from a recycled donor, and none of these mass parts sellers check them. They strip the carcass of it's boards, sell them, and replace or refund the money if they get a complaint. If the donor TV failed with the same defective board you have, you'll have the same issue.

This is why we go through several tests before estimating the job for the customer, and why we repair about 95 percent of the boards we see.

There are several guys in our association that sell parts on ebay, but these guys are technicians who will only sell verified boards.

The good news is that Electroparts is a good company and they'll replace or refund without question.

the short is still there, with the lvds cable removed. just bought the tcon board.?


You're confusing me. Are you saying that both the original TCON board and the one you just bought are showing a low ohm short to ground as read on that ferrite bead near the LVDS cable?



I put the original main board back in, and got two 12v & 5v inputs to the tcon on cn702..

Again, see if there is any 12DC voltage on the LVDS connector when it is disconnected from the TCON. IIRC, the CN702 connector goes to the power supply, not the main. Is there 12V on the LVDS connector when it is lifted off the TCON?

yes, both the original TCON boards fb are shorted. no 12v when lvds is disconnected.

 

[Fox's Mercantile]

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