Projection tv picture went out

C

Chris

Guest
I have an Akai PT5598HD 55 inch rear projection CRT television (made by
Samsung). The other day, the screen suddenly went blank. Everything else
(channel, input, sound, etc.) works perfect. Any self diagnosis/repair
suggestions would be greatly appreciated.

Thanks,

Chris
 
On Wed, 13 Jan 2010 20:16:16 -0800, "Chris" <reddd@juno.com>wrote:

I have an Akai PT5598HD 55 inch rear projection CRT television (made by
Samsung). The other day, the screen suddenly went blank. Everything else
(channel, input, sound, etc.) works perfect. Any self diagnosis/repair
suggestions would be greatly appreciated.

Thanks,

Chris
Click to expand...
Unless you have some experience in electronic repair my only
suggestion is to have a professional look at it.

One thing I'd like to ask is does the on screen display still work for
things like channel indicator or volume?
 
"Meat Plow" wrote in message news:3ek3q3.im4.17.3@news.alt.net...
On Wed, 13 Jan 2010 20:16:16 -0800, "Chris" <reddd@juno.com>wrote:

I have an Akai PT5598HD 55 inch rear projection CRT television (made by
Samsung). The other day, the screen suddenly went blank. Everything else
(channel, input, sound, etc.) works perfect. Any self diagnosis/repair
suggestions would be greatly appreciated.

Thanks,

Chris

Unless you have some experience in electronic repair my only
suggestion is to have a professional look at it.

One thing I'd like to ask is does the on screen display still work for
things like channel indicator or volume?
Click to expand...
No. Totally blank just like the set is turned off. I looked at the picture
tubes and there is no orange glow. I have done minor electronic repairs.
Also, I do HVAC, so I am well experienced in electrical
troubleshooting/repairs. If I can positively identify the source of the
problem, I can most likely do the repair. I'm willing to give it a shot
before I pay someone $75 only to tell me that the repairs will exceed the
cost of the tv.
 
On Thu, 14 Jan 2010 08:55:49 -0800, "Chris" <reddd@juno.com>wrote:

"Meat Plow" wrote in message news:3ek3q3.im4.17.3@news.alt.net...
On Wed, 13 Jan 2010 20:16:16 -0800, "Chris" <reddd@juno.com>wrote:

I have an Akai PT5598HD 55 inch rear projection CRT television (made by
Samsung). The other day, the screen suddenly went blank. Everything else
(channel, input, sound, etc.) works perfect. Any self diagnosis/repair
suggestions would be greatly appreciated.

Thanks,

Chris

Unless you have some experience in electronic repair my only
suggestion is to have a professional look at it.

One thing I'd like to ask is does the on screen display still work for
things like channel indicator or volume?

No. Totally blank just like the set is turned off. I looked at the picture
tubes and there is no orange glow. I have done minor electronic repairs.
Also, I do HVAC, so I am well experienced in electrical
troubleshooting/repairs. If I can positively identify the source of the
problem, I can most likely do the repair. I'm willing to give it a shot
before I pay someone $75 only to tell me that the repairs will exceed the
cost of the tv.
Click to expand...
Since you can obviously use a voltmeter you need to start with a print
of the power supply and voltage chart at certain test points. You
might plug the model number of the set into Google.com and see if
there are others who experienced the same/similar failure. Google also
might help to secure a schematic. I know by reading some Samsung
chassis had common faults for convergence processing components and
CRT leaks.

You also might want to pull the chassis out and give it a good visual
in plenty of light, maybe something will show up. Visual inspection
was always my first step and often can narrow down your trouble
shooting steps. Heck it could be something as simple as an onboard
fuse or fusable link and those can be checked with minimal effort.

Also certain models had built in error codes that made the power
indicator blink in certain patterns depending on thefault. Check into
that. Also check that the AC cord is supplying the set. I've seen
simple failures like this many times.
 
Good luck with this. Maybe there is a way to determine what equivalent model
Samsung chassis it is? Can you take some pictures of the insides showing the
boards?



"Chris" <reddd@juno.com> wrote in message
news:mUw3n.7127$nR4.2856@newsfe01.iad...
I have an Akai PT5598HD 55 inch rear projection CRT television (made by
Samsung). The other day, the screen suddenly went blank. Everything else
(channel, input, sound, etc.) works perfect. Any self diagnosis/repair
suggestions would be greatly appreciated.

Thanks,

Chris
Click to expand...
 
Chris wrote:
I have an Akai PT5598HD 55 inch rear projection CRT television (made by
Samsung). The other day, the screen suddenly went blank. Everything else
(channel, input, sound, etc.) works perfect. Any self diagnosis/repair
suggestions would be greatly appreciated.

Thanks,

Chris
Click to expand...
Just be aware, if you're not already, that CRTs have some particular
safety issues. One of which is that they can give you a nasty electric
shock long after the set's been turned off.

Sylvia.
 
"Sylvia Else" <sylvia@not.at.this.address> wrote in message
news:0031b231$0$28425$c3e8da3@news.astraweb.com...
Chris wrote:
I have an Akai PT5598HD 55 inch rear projection CRT television (made by
Samsung). The other day, the screen suddenly went blank. Everything else
(channel, input, sound, etc.) works perfect. Any self diagnosis/repair
suggestions would be greatly appreciated.

Thanks,

Chris

Just be aware, if you're not already, that CRTs have some particular
safety issues. One of which is that they can give you a nasty electric
shock long after the set's been turned off.

Sylvia.
Click to expand...
Thanks! I AM aware of this. But to clarify things, I have read that such
components remain energized long after the set has been turned off. Mine has
been unplugged for a week now. How long after being unplugged is a
reasonable amount of time to insure all the energy is dissipated? My work
schedule has precluded me from doing any further diagnosis since the problem
began (last Saturday). However, once I start looking at (energizing) it
again, I need to know how long I should wait after I unplug it to start
probing around.

To the other posters, I haven't responded since I haven't done anything else
yet. But you will be the first to know when I do.

Chris
 
Chris wrote:
"Sylvia Else" <sylvia@not.at.this.address> wrote in message
news:0031b231$0$28425$c3e8da3@news.astraweb.com...
Chris wrote:
I have an Akai PT5598HD 55 inch rear projection CRT television (made
by Samsung). The other day, the screen suddenly went blank.
Everything else (channel, input, sound, etc.) works perfect. Any self
diagnosis/repair suggestions would be greatly appreciated.

Thanks,

Chris

Just be aware, if you're not already, that CRTs have some particular
safety issues. One of which is that they can give you a nasty electric
shock long after the set's been turned off.

Sylvia.

Thanks! I AM aware of this. But to clarify things, I have read that such
components remain energized long after the set has been turned off. Mine
has been unplugged for a week now. How long after being unplugged is a
reasonable amount of time to insure all the energy is dissipated?
Click to expand...
Some of the material I've read indicates that charge gets embedded (for
the want of a better word) into the glass, and leaks out over a period
that can extend into months. So you can't assume that leaving it
unplugged for a week solves the problem. If you're going near the tube,
you need to discharge it, and you need to be aware that if you leave it
for a while (a vague expression meaning I don't know how long), then you
need to discharge it again.

Descriptions of the extent of the problem range from "not really a
problem at all" to "it can kill you". I don't know how to judge between
them.

Search Google for discharge +CRT

Sylvia.
 
stratus46@yahoo.com wrote:
On Jan 18, 1:27 pm, "Chris" <re...@juno.com> wrote:
"Sylvia Else" <syl...@not.at.this.address> wrote in message

news:0031b231$0$28425$c3e8da3@news.astraweb.com...

Chris wrote:
I have an Akai PT5598HD 55 inch rear projection CRT television (made by
Samsung). The other day, the screen suddenly went blank. Everything else
(channel, input, sound, etc.) works perfect. Any self diagnosis/repair
suggestions would be greatly appreciated.
Thanks,
Chris
Just be aware, if you're not already, that CRTs have some particular
safety issues. One of which is that they can give you a nasty electric
shock long after the set's been turned off.
Sylvia.
Thanks! I AM aware of this. But to clarify things, I have read that such
components remain energized long after the set has been turned off. Mine has
been unplugged for a week now. How long after being unplugged is a
reasonable amount of time to insure all the energy is dissipated? My work
schedule has precluded me from doing any further diagnosis since the problem
began (last Saturday). However, once I start looking at (energizing) it
again, I need to know how long I should wait after I unplug it to start
probing around.

To the other posters, I haven't responded since I haven't done anything else
yet. But you will be the first to know when I do.

Chris

Hard to believe a charge would still be there after a week but if is
was and you managed to discharge it through you, you'd be annoyed and
not dead. It's like touching a spark plug. Oh, you haven't done that
either? Of course you _could_ use a clip lead and screwdriver to
discharge it painlessly.
Click to expand...
While wearing protective eyewear, of course, incase you manage to
implode the tube.

Sylvia.
 
On Jan 18, 1:27 pm, "Chris" <re...@juno.com> wrote:
"Sylvia Else" <syl...@not.at.this.address> wrote in message

news:0031b231$0$28425$c3e8da3@news.astraweb.com...

Chris wrote:
I have an Akai PT5598HD 55 inch rear projection CRT television (made by
Samsung). The other day, the screen suddenly went blank. Everything else
(channel, input, sound, etc.) works perfect. Any self diagnosis/repair
suggestions would be greatly appreciated.

Thanks,

Chris

Just be aware, if you're not already, that CRTs have some particular
safety issues. One of which is that they can give you a nasty electric
shock long after the set's been turned off.

Sylvia.

Thanks! I AM aware of this. But to clarify things, I have read that such
components remain energized long after the set has been turned off. Mine has
been unplugged for a week now. How long after being unplugged is a
reasonable amount of time to insure all the energy is dissipated? My work
schedule has precluded me from doing any further diagnosis since the problem
began (last Saturday). However, once I start looking at (energizing) it
again, I need to know how long I should wait after I unplug it to start
probing around.

To the other posters, I haven't responded since I haven't done anything else
yet. But you will be the first to know when I do.

Chris
Click to expand...
Hard to believe a charge would still be there after a week but if is
was and you managed to discharge it through you, you'd be annoyed and
not dead. It's like touching a spark plug. Oh, you haven't done that
either? Of course you _could_ use a clip lead and screwdriver to
discharge it painlessly. I look at your problem as a fantastic
opportunity to get that NEW TV you've been looking at.

G˛
 
Sylvia Else wrote:
Chris wrote:

"Sylvia Else" <sylvia@not.at.this.address> wrote in message
news:0031b231$0$28425$c3e8da3@news.astraweb.com...
Chris wrote:
I have an Akai PT5598HD 55 inch rear projection CRT television (made
by Samsung). The other day, the screen suddenly went blank.
Everything else (channel, input, sound, etc.) works perfect. Any
self diagnosis/repair suggestions would be greatly appreciated.

Thanks,

Chris

Just be aware, if you're not already, that CRTs have some particular
safety issues. One of which is that they can give you a nasty
electric shock long after the set's been turned off.

Sylvia.

Thanks! I AM aware of this. But to clarify things, I have read that
such components remain energized long after the set has been turned
off. Mine has been unplugged for a week now. How long after being
unplugged is a reasonable amount of time to insure all the energy is
dissipated?

Some of the material I've read indicates that charge gets embedded (for
the want of a better word) into the glass, and leaks out over a period
that can extend into months. So you can't assume that leaving it
unplugged for a week solves the problem. If you're going near the tube,
you need to discharge it, and you need to be aware that if you leave it
for a while (a vague expression meaning I don't know how long), then you
need to discharge it again.

Descriptions of the extent of the problem range from "not really a
problem at all" to "it can kill you". I don't know how to judge between
them.

Search Google for discharge +CRT
Click to expand...
How to discharge your CRT without damaging it or getting shocked:

First, disconnect the TV from AC power!...

Using a long wire clip lead, connect one end of a long lead 10k (2 watts
or more) resistor to the CRT ground (usually there is a metal band
around the CRT - use that or a connecting metal bracket as a ground - DO
NOT use the PCB chassis ground). You will be using the other end of the
resistor to discharge the CRT. A safe, easy way to accomplish this is to
securely tape the resistor to the long end of a plastic coat hanger with
masking or electrical tape, and use the other end of the hanger as a
handle.

With one hand, use a 12" plastic ruler to carefully pry up the edge of
the high voltage "suction cup" on the CRT. Using your other hand, touch
the end of the resistor on the hanger to the anode contacts under the
cup. You will see a spark and hear a 'pop' when it discharges
(alternately, you could just slide the resistor under the cup until it
touches the contacts, but be careful not to scratch the conductive
coating on the CRT). Hold the resistor against the contacts for a few
seconds. Remove it and move the clip lead up to the other end of the
resistor. Now, touch the end of the resistor to the contacts again so
that you are directly shorting the CRT to ground.

It's now safe to remove the anode cup from the CRT. While wearing safety
glasses, you can use a screwdriver to carefully depress one of the
contacts under the cup and then remove it, but be very careful not to
scratch the conductive coating or damage the CRT when you do this. After
you have removed the cup, short the exposed contact on the CRT to ground
again just to be on the safe side. You will probably see a much smaller
spark, if any.

When you are ready to reconnect the CRT cable, short the contact on the
CRT to ground once more first. The CRT may have recovered enough charge
to zap you, so you want to short it out again just before you replace
the cup.
 
On Jan 18, 2:37 pm, Sylvia Else <syl...@not.at.this.address> wrote:
Chris wrote:

"Sylvia Else" <syl...@not.at.this.address> wrote in message
news:0031b231$0$28425$c3e8da3@news.astraweb.com...
Chris wrote:
I have an Akai PT5598HD 55 inch rear projection CRT television (made
by Samsung). The other day, the screen suddenly went blank.
Everything else (channel, input, sound, etc.) works perfect. Any self
diagnosis/repair suggestions would be greatly appreciated.

Thanks,

Chris

Just be aware, if you're not already, that CRTs have some particular
safety issues. One of which is that they can give you a nasty electric
shock long after the set's been turned off.

Sylvia.

Thanks! I AM aware of this. But to clarify things, I have read that such
components remain energized long after the set has been turned off. Mine
has been unplugged for a week now. How long after being unplugged is a
reasonable amount of time to insure all the energy is dissipated?

Some of the material I've read indicates that charge gets embedded (for
the want of a better word) into the glass, and leaks out over a period
that can extend into months. So you can't assume that leaving it
unplugged for a week solves the problem. If you're going near the tube,
you need to discharge it, and you need to be aware that if you leave it
for a while (a vague expression meaning I don't know how long), then you
need to discharge it again.

Descriptions of the extent of the problem range from "not really a
problem at all" to "it can kill you". I don't know how to judge between
them.

Search Google for discharge +CRT

Sylvia.
Click to expand...
It's possible the glass acts like an electret but my suspicion was
always that the coatings on the CRT surfaces are distributed
resistances and capacitances so when you 'discharge' the tube you
really only discharged a 'zone' around the discharge point and the
charges will migrate after the short is gone. Or maybe its just magic.

G˛
 
On Jan 18, 8:19 pm, stratu...@yahoo.com wrote:
On Jan 18, 2:37 pm, Sylvia Else <syl...@not.at.this.address> wrote:



Chris wrote:

"Sylvia Else" <syl...@not.at.this.address> wrote in message
news:0031b231$0$28425$c3e8da3@news.astraweb.com...
Chris wrote:
I have an Akai PT5598HD 55 inch rear projection CRT television (made
by Samsung). The other day, the screen suddenly went blank.
Everything else (channel, input, sound, etc.) works perfect. Any self
diagnosis/repair suggestions would be greatly appreciated.

Thanks,

Chris

Just be aware, if you're not already, that CRTs have some particular
safety issues. One of which is that they can give you a nasty electric
shock long after the set's been turned off.

Sylvia.

Thanks! I AM aware of this. But to clarify things, I have read that such
components remain energized long after the set has been turned off. Mine
has been unplugged for a week now. How long after being unplugged is a
reasonable amount of time to insure all the energy is dissipated?

Some of the material I've read indicates that charge gets embedded (for
the want of a better word) into the glass, and leaks out over a period
that can extend into months. So you can't assume that leaving it
unplugged for a week solves the problem. If you're going near the tube,
you need to discharge it, and you need to be aware that if you leave it
for a while (a vague expression meaning I don't know how long), then you
need to discharge it again.

Descriptions of the extent of the problem range from "not really a
problem at all" to "it can kill you". I don't know how to judge between
them.

Search Google for discharge +CRT

Sylvia.

It's possible the glass acts like an electret but my suspicion was
always that the coatings on the CRT surfaces are distributed
resistances and capacitances so when you 'discharge' the tube you
really only discharged a 'zone' around the discharge point and the
charges will migrate after the short is gone. Or maybe its just magic.

G˛
Click to expand...
It's just like a capacitor, hence the conductive outer coating. It can
migrate, but not usually to an amount to worry about. Nothing at room
temperature has zero resistance, so there is always some charge that
will migrate, to eventually even out over the substrate.
 
On Jan 18, 5:47 pm, Sofa Slug <sofas...@invalid.invalid> wrote:
Sylvia Else wrote:
Chris wrote:

"Sylvia Else" <syl...@not.at.this.address> wrote in message
news:0031b231$0$28425$c3e8da3@news.astraweb.com...
Chris wrote:
I have an Akai PT5598HD 55 inch rear projection CRT television (made
by Samsung). The other day, the screen suddenly went blank.
Everything else (channel, input, sound, etc.) works perfect. Any
self diagnosis/repair suggestions would be greatly appreciated.

Thanks,

Chris

Just be aware, if you're not already, that CRTs have some particular
safety issues. One of which is that they can give you a nasty
electric shock long after the set's been turned off.

Sylvia.

Thanks! I AM aware of this. But to clarify things, I have read that
such components remain energized long after the set has been turned
off. Mine has been unplugged for a week now. How long after being
unplugged is a reasonable amount of time to insure all the energy is
dissipated?

Some of the material I've read indicates that charge gets embedded (for
the want of a better word) into the glass, and leaks out over a period
that can extend into months. So you can't assume that leaving it
unplugged for a week solves the problem. If you're going near the tube,
you need to discharge it, and you need to be aware that if you leave it
for a while (a vague expression meaning I don't know how long), then you
need to discharge it again.

Descriptions of the extent of the problem range from "not really a
problem at all" to "it can kill you". I don't know how to judge between
them.

Search Google for discharge +CRT

How to discharge your CRT without damaging it or getting shocked:

First, disconnect the TV from AC power!...

Using a long wire clip lead, connect one end of a long lead 10k (2 watts
or more) resistor to the CRT ground (usually there is a metal band
around the CRT - use that or a connecting metal bracket as a ground - DO
NOT use the PCB chassis ground). You will be using the other end of the
resistor to discharge the CRT. A safe, easy way to accomplish this is to
securely tape the resistor to the long end of a plastic coat hanger with
masking or electrical tape, and use the other end of the hanger as a
handle.

With one hand, use a 12" plastic ruler to carefully pry up the edge of
the high voltage "suction cup" on the CRT. Using your other hand, touch
the end of the resistor on the hanger to the anode contacts under the
cup. You will see a spark and hear a 'pop' when it discharges
(alternately, you could just slide the resistor under the cup until it
touches the contacts, but be careful not to scratch the conductive
coating on the CRT). Hold the resistor against the contacts for a few
seconds. Remove it and move the clip lead up to the other end of the
resistor. Now, touch the end of the resistor to the contacts again so
that you are directly shorting the CRT to ground.

It's now safe to remove the anode cup from the CRT. While wearing safety
glasses, you can use a screwdriver to carefully depress one of the
contacts under the cup and then remove it, but be very careful not to
scratch the conductive coating or damage the CRT when you do this. After
you have removed the cup, short the exposed contact on the CRT to ground
again just to be on the safe side. You will probably see a much smaller
spark, if any.

When you are ready to reconnect the CRT cable, short the contact on the
CRT to ground once more first. The CRT may have recovered enough charge
to zap you, so you want to short it out again just before you replace
the cup.
Click to expand...
I'm glad to see someone explaining this in english. I started working
on televisions eons ago, before the internet, as a kid, and it took
me forever to figure out how to ground out the crt without killing it,
me, or other circuitry.
 
<stratus46@yahoo.com> wrote in message
news:bc4c9b3a-bec5-446a-aa82-7e29bc6d9ef8@e16g2000yqc.googlegroups.com...
On Jan 18, 1:27 pm, "Chris" <re...@juno.com> wrote:
"Sylvia Else" <syl...@not.at.this.address> wrote in message

news:0031b231$0$28425$c3e8da3@news.astraweb.com...

Chris wrote:
I have an Akai PT5598HD 55 inch rear projection CRT television (made by
Samsung). The other day, the screen suddenly went blank. Everything
else
(channel, input, sound, etc.) works perfect. Any self diagnosis/repair
suggestions would be greatly appreciated.

Thanks,

Chris

Just be aware, if you're not already, that CRTs have some particular
safety issues. One of which is that they can give you a nasty electric
shock long after the set's been turned off.

Sylvia.

Thanks! I AM aware of this. But to clarify things, I have read that such
components remain energized long after the set has been turned off. Mine
has
been unplugged for a week now. How long after being unplugged is a
reasonable amount of time to insure all the energy is dissipated? My work
schedule has precluded me from doing any further diagnosis since the
problem
began (last Saturday). However, once I start looking at (energizing) it
again, I need to know how long I should wait after I unplug it to start
probing around.

To the other posters, I haven't responded since I haven't done anything
else
yet. But you will be the first to know when I do.

Chris
Click to expand...
Hard to believe a charge would still be there after a week but if is
was and you managed to discharge it through you, you'd be annoyed and
not dead.

***************
I found this: "The CRT attached to the flyback has an inherent capacitance
which can hold a high voltage charge for up to a week or more after the
power is switched off." http://en.wikipedia.org/wiki/Flyback_transformer

**************

It's like touching a spark plug. Oh, you haven't done that
either? Of course you _could_ use a clip lead and screwdriver to
discharge it painlessly. I look at your problem as a fantastic
opportunity to get that NEW TV you've been looking at.

G˛

************
I have considered a new tv, but since this one is not that old, and
considering the cost of new, I prefer to repair it. Anyway, all three (red,
blue, green) CRTs went out simultaneously. That tells me that it is probably
something other than the CRTs; perhaps the flyback. What do you think?
 
"Meat Plow" wrote in message news:3ekb7n.act.17.9@news.alt.net...
On Thu, 14 Jan 2010 08:55:49 -0800, "Chris" <reddd@juno.com>wrote:


"Meat Plow" wrote in message news:3ek3q3.im4.17.3@news.alt.net...
On Wed, 13 Jan 2010 20:16:16 -0800, "Chris" <reddd@juno.com>wrote:

I have an Akai PT5598HD 55 inch rear projection CRT television (made by
Samsung). The other day, the screen suddenly went blank. Everything else
(channel, input, sound, etc.) works perfect. Any self diagnosis/repair
suggestions would be greatly appreciated.

Thanks,

Chris

Unless you have some experience in electronic repair my only
suggestion is to have a professional look at it.

One thing I'd like to ask is does the on screen display still work for
things like channel indicator or volume?

No. Totally blank just like the set is turned off. I looked at the picture
tubes and there is no orange glow. I have done minor electronic repairs.
Also, I do HVAC, so I am well experienced in electrical
troubleshooting/repairs. If I can positively identify the source of the
problem, I can most likely do the repair. I'm willing to give it a shot
before I pay someone $75 only to tell me that the repairs will exceed the
cost of the tv.

Since you can obviously use a voltmeter you need to start with a print
of the power supply and voltage chart at certain test points. You
might plug the model number of the set into Google.com and see if
there are others who experienced the same/similar failure. Google also
might help to secure a schematic. I know by reading some Samsung
chassis had common faults for convergence processing components and
CRT leaks.

You also might want to pull the chassis out and give it a good visual
in plenty of light, maybe something will show up. Visual inspection
was always my first step and often can narrow down your trouble
shooting steps. Heck it could be something as simple as an onboard
fuse or fusable link and those can be checked with minimal effort.

Also certain models had built in error codes that made the power
indicator blink in certain patterns depending on thefault. Check into
that. Also check that the AC cord is supplying the set. I've seen
simple failures like this many times.
Click to expand...
Well, I finally broke down and sprung the 80 bucks, and had a tech come over
this morning. He said the deflection board has to be replaced. He explained
how relatively easy it was to do, and that with my experience, it should be
no problem. Not to mention, will be significantly cheaper doing it myself.
He also turned me on to a couple web sites that their own company uses for
parts. I will have to wait until Monday to contact them since I am having
limited luck finding the part online. In case anyone has a desire to help me
locate it, the model info is at the beginning of this post. I have
additional numbers if need be.

Thanks
 
May not need to take photos, but will if necessary. I know what the problem
is as indicated in my other post today. I will try to locate the part
Monday. But if I hit dead ends, I can post a photo.

"circuit" <circuit@123456.tv> wrote in message
news:hio7tp$dp4$1@speranza.aioe.org...
Good luck with this. Maybe there is a way to determine what equivalent
model
Samsung chassis it is? Can you take some pictures of the insides showing
the
boards?



"Chris" <reddd@juno.com> wrote in message
news:mUw3n.7127$nR4.2856@newsfe01.iad...
I have an Akai PT5598HD 55 inch rear projection CRT television (made by
Samsung). The other day, the screen suddenly went blank. Everything else
(channel, input, sound, etc.) works perfect. Any self diagnosis/repair
suggestions would be greatly appreciated.

Thanks,

Chris
Click to expand...
 
"Sansui Samari" <jimjam1942@gmail.com> wrote in message
news:0dd5f9e2-6f94-42b9-bcb5-23b9030cd1b7@14g2000yqp.googlegroups.com...
On Jan 18, 5:47 pm, Sofa Slug <sofas...@invalid.invalid> wrote:
Sylvia Else wrote:
Chris wrote:

"Sylvia Else" <syl...@not.at.this.address> wrote in message
news:0031b231$0$28425$c3e8da3@news.astraweb.com...
Chris wrote:
I have an Akai PT5598HD 55 inch rear projection CRT television (made
by Samsung). The other day, the screen suddenly went blank.
Everything else (channel, input, sound, etc.) works perfect. Any
self diagnosis/repair suggestions would be greatly appreciated.

Thanks,

Chris

Just be aware, if you're not already, that CRTs have some particular
safety issues. One of which is that they can give you a nasty
electric shock long after the set's been turned off.

Sylvia.

Thanks! I AM aware of this. But to clarify things, I have read that
such components remain energized long after the set has been turned
off. Mine has been unplugged for a week now. How long after being
unplugged is a reasonable amount of time to insure all the energy is
dissipated?

Some of the material I've read indicates that charge gets embedded (for
the want of a better word) into the glass, and leaks out over a period
that can extend into months. So you can't assume that leaving it
unplugged for a week solves the problem. If you're going near the tube,
you need to discharge it, and you need to be aware that if you leave it
for a while (a vague expression meaning I don't know how long), then you
need to discharge it again.

Descriptions of the extent of the problem range from "not really a
problem at all" to "it can kill you". I don't know how to judge between
them.

Search Google for discharge +CRT

How to discharge your CRT without damaging it or getting shocked:

First, disconnect the TV from AC power!...

Using a long wire clip lead, connect one end of a long lead 10k (2 watts
or more) resistor to the CRT ground (usually there is a metal band
around the CRT - use that or a connecting metal bracket as a ground - DO
NOT use the PCB chassis ground). You will be using the other end of the
resistor to discharge the CRT. A safe, easy way to accomplish this is to
securely tape the resistor to the long end of a plastic coat hanger with
masking or electrical tape, and use the other end of the hanger as a
handle.

With one hand, use a 12" plastic ruler to carefully pry up the edge of
the high voltage "suction cup" on the CRT. Using your other hand, touch
the end of the resistor on the hanger to the anode contacts under the
cup. You will see a spark and hear a 'pop' when it discharges
(alternately, you could just slide the resistor under the cup until it
touches the contacts, but be careful not to scratch the conductive
coating on the CRT). Hold the resistor against the contacts for a few
seconds. Remove it and move the clip lead up to the other end of the
resistor. Now, touch the end of the resistor to the contacts again so
that you are directly shorting the CRT to ground.

It's now safe to remove the anode cup from the CRT. While wearing safety
glasses, you can use a screwdriver to carefully depress one of the
contacts under the cup and then remove it, but be very careful not to
scratch the conductive coating or damage the CRT when you do this. After
you have removed the cup, short the exposed contact on the CRT to ground
again just to be on the safe side. You will probably see a much smaller
spark, if any.

When you are ready to reconnect the CRT cable, short the contact on the
CRT to ground once more first. The CRT may have recovered enough charge
to zap you, so you want to short it out again just before you replace
the cup.
Click to expand...
I'm glad to see someone explaining this in english. I started working
on televisions eons ago, before the internet, as a kid, and it took
me forever to figure out how to ground out the crt without killing it,
me, or other circuitry.

**************

I finally located the "no longer available" deflection board for my tv.
Ordered it today. Will post the results when I get it replaced.
 
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