plasma tv PSU

M

Michael Kennedy

Guest
Ok.. I have a Hitachi W32-P5000 with a MPF7409 power supply. The unit seems
to be more or less the same as a PD5000 with the same display panel aside
from lacking an internal tuner.
<http://www.scribd.com/doc/28551723/Hitachi-PD5000-5200-Series-Plasma-Service-Manual>


Anyhow. The TV is intermittantly shutting down. It is not regular at all. It
seems to ony do it from a cold start, although I can't seem to make it shut
down using freeze spay. When the TV shuts down the power light stays green
as if it were still on, although the power supply drops all voltage from VS
and VA.

Seems to match a symtom listed in a service buliton
<http://tinyurl.com/2dxycnb> (42PD5000 service tips.pdf)
I removed the board IC202 and resoldered it as recomended, but didn't cure
the problem. Since the PSU is clicking a lot before it shuts down, I also
checked for bad caps with my ESR meter to no avail either.

Another strange thing is when operating is that VS: is 182.5VAC and VA: is
136.4VAC Although they are rated for VS: 84.6V VA: 63.1V... This is so
different that I would think that my meter must be not working correctly.
Unfortunately the only meter I have right now is a cheapo $5 unit. There
is also listing for VW: 189.1 and VX: 54.8 although I cant see the test
points for these.

Anyhow, I was hoping to fix this problem before it got worse and blew
something else up in the TV, but it is not cooperating and is working how it
should...

Any thoughts?
 
Just to add to this..


The tv works fine all PSU voltages within specs.. Then it starts clicking a
bit and then shuts down. Seems to click when the brightness changes on the
TV. (Dark picture to bright picture) and it seems to fail more on bright
pictures like cartoons.

When it shuts down it wont restart until the power is removed completely.
The standby light will change from red to green, but to no avail. The 300V
doesn't come up in the PSU. No Vcc only STB voltage. Unplug it plug it back
in and comes right up.

Poking around with freeze spray on some of the suspect components recomended
by the service manual it will shut down, but not instantly as expected. It
takes a minute or two...

Im puzzled what the clicking soud inside this thing is. It is not the
relays and the intensity changes. It always clicks a few times while warming
up.
 
<stratus46@yahoo.com> wrote in message
news:fb454847-244f-458b-8b12-56b687ac311e@j5g2000vbg.googlegroups.com...
On Sep 16, 11:27 pm, "Michael Kennedy" <mike@com> wrote:
Just to add to this..

The tv works fine all PSU voltages within specs.. Then it starts clicking
a
bit and then shuts down. Seems to click when the brightness changes on the
TV. (Dark picture to bright picture) and it seems to fail more on bright
pictures like cartoons.

When it shuts down it wont restart until the power is removed completely.
The standby light will change from red to green, but to no avail. The 300V
doesn't come up in the PSU. No Vcc only STB voltage. Unplug it plug it
back
in and comes right up.

Poking around with freeze spray on some of the suspect components
recomended
by the service manual it will shut down, but not instantly as expected. It
takes a minute or two...

Im puzzled what the clicking soud inside this thing is. It is not the
relays and the intensity changes. It always clicks a few times while
warming
up.
Click to expand...
Replace the bad 'lytics and check again. Got an ESR meter? If not,
it's time. Even the cheapy $50 MAT Electronics meter will do OK. SMPSs
are particularly fussy about the caps. 'OK' rarely is OK. Secondary
outputs have to be very good. Panasonic FM, Nichicon PW, HM, HN an HZ
series caps are good. For SMT caps Panasonic FK and FP are good.

G˛

I have a bob parker mk2 meter that I buit a few years back. I poked around
with it and didnt find any bad caps, although I didnt remove them all from
circuit. I have my suspiscions that it is bad caps though. There is a
serivce buletion that says to check the 2 400V 250uF caps. They checked ok
out of circuit.. I guess I will double check all the caps again.
 
On Sep 16, 11:27 pm, "Michael Kennedy" <mike@com> wrote:
Just to add to this..

The tv works fine all PSU voltages within specs.. Then it starts clicking a
bit and then shuts down. Seems to click when the brightness changes on the
TV. (Dark picture to bright picture) and it seems to fail more on bright
pictures like cartoons.

When it shuts down it wont restart until the power is removed completely.
The standby light will change from red to green, but to no avail. The 300V
doesn't come up in the PSU. No Vcc only STB voltage. Unplug it plug it back
in and comes right up.

Poking around with freeze spray on some of the suspect components recomended
by the service manual  it will shut down, but not instantly as expected.. It
takes a minute or two...

Im puzzled what the clicking soud  inside this thing is. It is not the
relays and the intensity changes. It always clicks a few times while warming
up.
Click to expand...
Replace the bad 'lytics and check again. Got an ESR meter? If not,
it's time. Even the cheapy $50 MAT Electronics meter will do OK. SMPSs
are particularly fussy about the caps. 'OK' rarely is OK. Secondary
outputs have to be very good. Panasonic FM, Nichicon PW, HM, HN an HZ
series caps are good. For SMT caps Panasonic FK and FP are good.

G˛

G˛
 
"Michael Kennedy" <mike@com> wrote in message
news:aPudnVVoJuu0jw7RnZ2dnVY3goSdnZ2d@giganews.com...
stratus46@yahoo.com> wrote in message
news:fb454847-244f-458b-8b12-56b687ac311e@j5g2000vbg.googlegroups.com...
On Sep 16, 11:27 pm, "Michael Kennedy" <mike@com> wrote:
Just to add to this..

The tv works fine all PSU voltages within specs.. Then it starts clicking
a
bit and then shuts down. Seems to click when the brightness changes on
the
TV. (Dark picture to bright picture) and it seems to fail more on bright
pictures like cartoons.

When it shuts down it wont restart until the power is removed completely.
The standby light will change from red to green, but to no avail. The
300V
doesn't come up in the PSU. No Vcc only STB voltage. Unplug it plug it
back
in and comes right up.

Poking around with freeze spray on some of the suspect components
recomended
by the service manual it will shut down, but not instantly as expected.
It
takes a minute or two...

Im puzzled what the clicking soud inside this thing is. It is not the
relays and the intensity changes. It always clicks a few times while
warming
up.

Replace the bad 'lytics and check again. Got an ESR meter? If not,
it's time. Even the cheapy $50 MAT Electronics meter will do OK. SMPSs
are particularly fussy about the caps. 'OK' rarely is OK. Secondary
outputs have to be very good. Panasonic FM, Nichicon PW, HM, HN an HZ
series caps are good. For SMT caps Panasonic FK and FP are good.

G˛

I have a bob parker mk2 meter that I buit a few years back. I poked around
with it and didnt find any bad caps, although I didnt remove them all from
circuit. I have my suspiscions that it is bad caps though. There is a
serivce buletion that says to check the 2 400V 250uF caps. They checked ok
out of circuit.. I guess I will double check all the caps again.
Click to expand...

If it's a Samsung 4264 or similar, look for bad solder at a couple of the
switcher transistors near the middle of the PSU. The eyelets were too small
and need to be scraped back and soldered.

Mark Z.
 
"Meat Plow" <mhywatt@yahoo.com> wrote in message
news:pan.2010.09.17.12.19.04@hahahahahahahah.nutz.I.am...
On Fri, 17 Sep 2010 15:27:49 +0900, Michael Kennedy wrote:

Just to add to this..


The tv works fine all PSU voltages within specs.. Then it starts
clicking a bit and then shuts down. Seems to click when the brightness
changes on the TV. (Dark picture to bright picture) and it seems to fail
more on bright pictures like cartoons.

When it shuts down it wont restart until the power is removed
completely. The standby light will change from red to green, but to no
avail. The 300V doesn't come up in the PSU. No Vcc only STB voltage.
Unplug it plug it back in and comes right up.

Poking around with freeze spray on some of the suspect components
recomended by the service manual it will shut down, but not instantly
as expected. It takes a minute or two...

Im puzzled what the clicking soud inside this thing is. It is not the
relays and the intensity changes. It always clicks a few times while
warming up.

Shotgun the caps in the PSU if you want to go to the time and expense. Do
the ones in close proximity to hot items like heat sinks, diodes, >1watt
resistors first. Placement of caps in those locations will always give
trouble eventually and have much shorter lives. Wish I had the set, this
is just the kind of troubleshooting challenge I love.
Click to expand...
Actually I enjoy it too, although this is my first switcher to fix.. I just
wish I had someone around to learn all the tricks from.
If I didn't enjoy it, I would just watch the tv as is becuase it functions
without issue most of the time or just buy a PSU thats been rebuilt for
$70.. I enjoy fixing anything that gives me a little challenge. This is the
first piece of equipment that I have ever cracked open which had a
sufficinetly detailed service manual.


Thanks for the tips.
 
"Mark Zacharias" <mark_zacharias@sbcglobal.net> wrote in message
news:4c9350b8$0$10327$c3e8da3@news.astraweb.com...
"Michael Kennedy" <mike@com> wrote in message
news:aPudnVVoJuu0jw7RnZ2dnVY3goSdnZ2d@giganews.com...

stratus46@yahoo.com> wrote in message
news:fb454847-244f-458b-8b12-56b687ac311e@j5g2000vbg.googlegroups.com...
On Sep 16, 11:27 pm, "Michael Kennedy" <mike@com> wrote:
Just to add to this..

The tv works fine all PSU voltages within specs.. Then it starts
clicking a
bit and then shuts down. Seems to click when the brightness changes on
the
TV. (Dark picture to bright picture) and it seems to fail more on bright
pictures like cartoons.

When it shuts down it wont restart until the power is removed
completely.
The standby light will change from red to green, but to no avail. The
300V
doesn't come up in the PSU. No Vcc only STB voltage. Unplug it plug it
back
in and comes right up.

Poking around with freeze spray on some of the suspect components
recomended
by the service manual it will shut down, but not instantly as expected.
It
takes a minute or two...

Im puzzled what the clicking soud inside this thing is. It is not the
relays and the intensity changes. It always clicks a few times while
warming
up.

Replace the bad 'lytics and check again. Got an ESR meter? If not,
it's time. Even the cheapy $50 MAT Electronics meter will do OK. SMPSs
are particularly fussy about the caps. 'OK' rarely is OK. Secondary
outputs have to be very good. Panasonic FM, Nichicon PW, HM, HN an HZ
series caps are good. For SMT caps Panasonic FK and FP are good.

G˛

I have a bob parker mk2 meter that I buit a few years back. I poked
around with it and didnt find any bad caps, although I didnt remove them
all from circuit. I have my suspiscions that it is bad caps though.
There is a serivce buletion that says to check the 2 400V 250uF caps.
They checked ok out of circuit.. I guess I will double check all the caps
again.


If it's a Samsung 4264 or similar, look for bad solder at a couple of the
switcher transistors near the middle of the PSU. The eyelets were too
small and need to be scraped back and soldered.

Mark Z.
Click to expand...
Its actually a Hitachi W32-5000 similar to a P5000 with a MPF4700 PSU

Thanks for the advice!
 
On Fri, 17 Sep 2010 15:27:49 +0900, Michael Kennedy wrote:

Just to add to this..


The tv works fine all PSU voltages within specs.. Then it starts
clicking a bit and then shuts down. Seems to click when the brightness
changes on the TV. (Dark picture to bright picture) and it seems to fail
more on bright pictures like cartoons.

When it shuts down it wont restart until the power is removed
completely. The standby light will change from red to green, but to no
avail. The 300V doesn't come up in the PSU. No Vcc only STB voltage.
Unplug it plug it back in and comes right up.

Poking around with freeze spray on some of the suspect components
recomended by the service manual it will shut down, but not instantly
as expected. It takes a minute or two...

Im puzzled what the clicking soud inside this thing is. It is not the
relays and the intensity changes. It always clicks a few times while
warming up.
Click to expand...
Shotgun the caps in the PSU if you want to go to the time and expense. Do
the ones in close proximity to hot items like heat sinks, diodes, >1watt
resistors first. Placement of caps in those locations will always give
trouble eventually and have much shorter lives. Wish I had the set, this
is just the kind of troubleshooting challenge I love.



--
Live Fast, Die Young and Leave a Pretty Corpse
 
On Fri, 17 Sep 2010 21:54:49 +0900, Michael Kennedy wrote:

"Meat Plow" <mhywatt@yahoo.com> wrote in message
news:pan.2010.09.17.12.19.04@hahahahahahahah.nutz.I.am...
On Fri, 17 Sep 2010 15:27:49 +0900, Michael Kennedy wrote:

Just to add to this..


The tv works fine all PSU voltages within specs.. Then it starts
clicking a bit and then shuts down. Seems to click when the brightness
changes on the TV. (Dark picture to bright picture) and it seems to
fail more on bright pictures like cartoons.

When it shuts down it wont restart until the power is removed
completely. The standby light will change from red to green, but to no
avail. The 300V doesn't come up in the PSU. No Vcc only STB voltage.
Unplug it plug it back in and comes right up.

Poking around with freeze spray on some of the suspect components
recomended by the service manual it will shut down, but not instantly
as expected. It takes a minute or two...

Im puzzled what the clicking soud inside this thing is. It is not the
relays and the intensity changes. It always clicks a few times while
warming up.

Shotgun the caps in the PSU if you want to go to the time and expense.
Do the ones in close proximity to hot items like heat sinks, diodes,
1watt resistors first. Placement of caps in those locations will
always give trouble eventually and have much shorter lives. Wish I had
the set, this is just the kind of troubleshooting challenge I love.




Actually I enjoy it too, although this is my first switcher to fix.. I
just wish I had someone around to learn all the tricks from. If I didn't
enjoy it, I would just watch the tv as is becuase it functions without
issue most of the time or just buy a PSU thats been rebuilt for $70.. I
enjoy fixing anything that gives me a little challenge. This is the
first piece of equipment that I have ever cracked open which had a
sufficinetly detailed service manual.


Thanks for the tips.
Click to expand...
You're welcome. I've now repaired 5 >400 watt PC PSUs. Used to just toss
them and buy new. A couple friends who saved the failed units gave me
these for parts so I decided to have a go at repair. The last unit was a
650 watt PSU that failed after a year. Made a chirp with then AC was
plugged in. Grounding the green PSU 'on' wire did nothing. Since I have
no ESR meter I took a count of the caps and their values and drove to a
local electronics supply store. I also gave the PSU a good visual, tested
some obvious fuse-able type resistors and some discrete semiconductors.
Also looked for bad solder and signs of hot components, discoloration,
you name it...whatever my past experiences had taught me not only with
switchers but any high power electronic device. Finding no obvious signs
of damages I purchased some replacement caps found in areas I described
above. Cost me about $20 US. Took me less than an hour to replace and
reassemble. I ended up with a spare 650 watt PSU. My new quad core AMD
based PC with a 120 watt CPU needs a minimum 600 watt supply. My NVidia
graphics card has a separate 12 volt plug since the PCIe bus cannot
deliver enough current. Also have 3 SATA hard drives and two DVD burners.
Lots of power hungry devices I don't want to tax a smaller PSU on. Plus I
overclock the quad PSU to 4 ghz and that requires a high degree of
voltage regulation precision. So not any old PSU will deliver. I've had
no problems since I bought the hardware back in July.



--
Live Fast, Die Young and Leave a Pretty Corpse
 
"Meat Plow" <mhywatt@yahoo.com> wrote in message
news:pan.2010.09.17.14.04.58@hahahahahahahah.nutz.I.am...
On Fri, 17 Sep 2010 21:54:49 +0900, Michael Kennedy wrote:

"Meat Plow" <mhywatt@yahoo.com> wrote in message
news:pan.2010.09.17.12.19.04@hahahahahahahah.nutz.I.am...
On Fri, 17 Sep 2010 15:27:49 +0900, Michael Kennedy wrote:

Just to add to this..


The tv works fine all PSU voltages within specs.. Then it starts
clicking a bit and then shuts down. Seems to click when the brightness
changes on the TV. (Dark picture to bright picture) and it seems to
fail more on bright pictures like cartoons.

When it shuts down it wont restart until the power is removed
completely. The standby light will change from red to green, but to no
avail. The 300V doesn't come up in the PSU. No Vcc only STB voltage.
Unplug it plug it back in and comes right up.

Poking around with freeze spray on some of the suspect components
recomended by the service manual it will shut down, but not instantly
as expected. It takes a minute or two...

Im puzzled what the clicking soud inside this thing is. It is not the
relays and the intensity changes. It always clicks a few times while
warming up.

Shotgun the caps in the PSU if you want to go to the time and expense.
Do the ones in close proximity to hot items like heat sinks, diodes,
1watt resistors first. Placement of caps in those locations will
always give trouble eventually and have much shorter lives. Wish I had
the set, this is just the kind of troubleshooting challenge I love.




Actually I enjoy it too, although this is my first switcher to fix.. I
just wish I had someone around to learn all the tricks from. If I didn't
enjoy it, I would just watch the tv as is becuase it functions without
issue most of the time or just buy a PSU thats been rebuilt for $70.. I
enjoy fixing anything that gives me a little challenge. This is the
first piece of equipment that I have ever cracked open which had a
sufficinetly detailed service manual.


Thanks for the tips.

You're welcome. I've now repaired 5 >400 watt PC PSUs. Used to just toss
them and buy new. A couple friends who saved the failed units gave me
these for parts so I decided to have a go at repair. The last unit was a
650 watt PSU that failed after a year. Made a chirp with then AC was
plugged in. Grounding the green PSU 'on' wire did nothing. Since I have
no ESR meter I took a count of the caps and their values and drove to a
local electronics supply store. I also gave the PSU a good visual, tested
some obvious fuse-able type resistors and some discrete semiconductors.
Also looked for bad solder and signs of hot components, discoloration,
you name it...whatever my past experiences had taught me not only with
switchers but any high power electronic device. Finding no obvious signs
of damages I purchased some replacement caps found in areas I described
above. Cost me about $20 US. Took me less than an hour to replace and
reassemble. I ended up with a spare 650 watt PSU. My new quad core AMD
based PC with a 120 watt CPU needs a minimum 600 watt supply. My NVidia
graphics card has a separate 12 volt plug since the PCIe bus cannot
deliver enough current. Also have 3 SATA hard drives and two DVD burners.
Lots of power hungry devices I don't want to tax a smaller PSU on. Plus I
overclock the quad PSU to 4 ghz and that requires a high degree of
voltage regulation precision. So not any old PSU will deliver. I've had
no problems since I bought the hardware back in July.
Click to expand...
On that note.. I just found a blackened cap which is close to a 2w resistor
which also appears to be black. New resistor and new cap time.
 
"Michael Kennedy" <mike@nospam.com> wrote in message
news:UPqdnYZpqOkgKQ7RnZ2dnVY3goidnZ2d@giganews.com...
"Meat Plow" <mhywatt@yahoo.com> wrote in message
news:pan.2010.09.17.14.04.58@hahahahahahahah.nutz.I.am...
On Fri, 17 Sep 2010 21:54:49 +0900, Michael Kennedy wrote:

"Meat Plow" <mhywatt@yahoo.com> wrote in message
news:pan.2010.09.17.12.19.04@hahahahahahahah.nutz.I.am...
On Fri, 17 Sep 2010 15:27:49 +0900, Michael Kennedy wrote:

Just to add to this..


The tv works fine all PSU voltages within specs.. Then it starts
clicking a bit and then shuts down. Seems to click when the brightness
changes on the TV. (Dark picture to bright picture) and it seems to
fail more on bright pictures like cartoons.

When it shuts down it wont restart until the power is removed
completely. The standby light will change from red to green, but to no
avail. The 300V doesn't come up in the PSU. No Vcc only STB voltage.
Unplug it plug it back in and comes right up.

Poking around with freeze spray on some of the suspect components
recomended by the service manual it will shut down, but not instantly
as expected. It takes a minute or two...

Im puzzled what the clicking soud inside this thing is. It is not the
relays and the intensity changes. It always clicks a few times while
warming up.

Shotgun the caps in the PSU if you want to go to the time and expense.
Do the ones in close proximity to hot items like heat sinks, diodes,
1watt resistors first. Placement of caps in those locations will
always give trouble eventually and have much shorter lives. Wish I had
the set, this is just the kind of troubleshooting challenge I love.




Actually I enjoy it too, although this is my first switcher to fix.. I
just wish I had someone around to learn all the tricks from. If I didn't
enjoy it, I would just watch the tv as is becuase it functions without
issue most of the time or just buy a PSU thats been rebuilt for $70.. I
enjoy fixing anything that gives me a little challenge. This is the
first piece of equipment that I have ever cracked open which had a
sufficinetly detailed service manual.


Thanks for the tips.

You're welcome. I've now repaired 5 >400 watt PC PSUs. Used to just toss
them and buy new. A couple friends who saved the failed units gave me
these for parts so I decided to have a go at repair. The last unit was a
650 watt PSU that failed after a year. Made a chirp with then AC was
plugged in. Grounding the green PSU 'on' wire did nothing. Since I have
no ESR meter I took a count of the caps and their values and drove to a
local electronics supply store. I also gave the PSU a good visual, tested
some obvious fuse-able type resistors and some discrete semiconductors.
Also looked for bad solder and signs of hot components, discoloration,
you name it...whatever my past experiences had taught me not only with
switchers but any high power electronic device. Finding no obvious signs
of damages I purchased some replacement caps found in areas I described
above. Cost me about $20 US. Took me less than an hour to replace and
reassemble. I ended up with a spare 650 watt PSU. My new quad core AMD
based PC with a 120 watt CPU needs a minimum 600 watt supply. My NVidia
graphics card has a separate 12 volt plug since the PCIe bus cannot
deliver enough current. Also have 3 SATA hard drives and two DVD burners.
Lots of power hungry devices I don't want to tax a smaller PSU on. Plus I
overclock the quad PSU to 4 ghz and that requires a high degree of
voltage regulation precision. So not any old PSU will deliver. I've had
no problems since I bought the hardware back in July.



On that note.. I just found a blackened cap which is close to a 2w
resistor which also appears to be black. New resistor and new cap time.
Click to expand...
Replaced all the smaller caps around hot areas and it appears to be working
ok,
although this tv still is making a clicking sound when heating up and
cooling down..
It really sounds like a relay, but It is something else.
 
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