Capacitor on last legs in Trinitron screen

[DS]

Got a 20" trinitron screen that takes ages to turn on. Everything I read
seems to point to a dying capacitor, probably one of the filter capacitors
being dried up, or some other capacitor in the power supply. If open it up,
how easy will it be to find this capacitor? What should I look for? How
should I go about testing it?

Thanks in advance!
-Dan

 

[David]

Post the rest of the missing required information for a response.
model number, ACTUAL symptoms, etc.

David

 

[Sam Goldwasser]

Got a 20" trinitron screen that takes ages to turn on. Everything I read
seems to point to a dying capacitor, probably one of the filter capacitors
being dried up, or some other capacitor in the power supply. If open it up,
how easy will it be to find this capacitor? What should I look for? How
should I go about testing it?

If someone happens to know which capacitor(s) tend to fail in that set,
then replacing them all should fix it. Otherwise, someone will have to
test each capacitor. This is generally done with an ESR meter. It's
quick and painless but you need the proper equipment.

More in the FAQs.

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Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
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| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header is ignored.
To contact me, please use the feedback form on the S.E.R FAQ Web sites.

 

[Mark D. Zacharias]

A common symptom of Sony tv's as they get older is the PICTURE TUBE cathode
emissions are lower, and the picture is blanked by the microprocessor until
the picture is considered watchable. If the picture is still somewhat
pastel-looking after it comes on, this is your problem, a bad picture tube.

Mark Z.

 

[DS]

Post the rest of the missing required information for a response.
model number, ACTUAL symptoms, etc.

David

Hi David, here is what I posted over in sci.electronics.misc.. the only
thing that needs
to be added is that the model is Dell D2026T, but it is based on a a Sony
Trinitron
tube. Thanks.
-------------------------
I've got a 20" Dell Trinitron CRT screen thats about 7 years old. Its been
going great until December when it started to take about 10 minutes to warm
up. Well now its up to almost half an hour.

Here's what happens: I push the power button (its a hard on/off; not a
standby); the green LED comes on and it degausses. It is then pitch black
(you know how normally when it is black it still has a some output.. not
anymore). It will remain pitch black without any sign that is alive (aside
from the LED) for about half an hour, then it suddenly comes to life in the
span of 20 seconds (from pitch black to a bright vibrant image).

If it flicks off into power standby mode even for a second (like when you
reboot for example), it will then be black for another 10 minutes before it
fades the image in (once again, 10mins of pure black, then a 20 second warm
up).

I don't think the tube is worn out since once its finished warming up it
works as well as day one.. I'm guessing its something to do with the
electronics.. any ideas what it may be?

Thanks in advance!
-Dan
[email protected]
(rem.ove no junk mail)

 

[DS]

A common symptom of Sony tv's as they get older is the PICTURE TUBE cathode
emissions are lower, and the picture is blanked by the microprocessor until
the picture is considered watchable. If the picture is still somewhat
pastel-looking after it comes on, this is your problem, a bad picture tube.

Mark Z.

Hi Mark,
I suppose that is a possibility, is there any way I can find out if that is
the problem? From what I read in the FAQs and the answers I got over in
sci.electoronics.misc, it was suggested that it is probably a bad capacitor,
but that could be wrong.

IIRC it was made in 1997. I bought it second hand in '99. While I use it, it
generally gets about 8 hours of use during the day; I shut it off at night
and when I'm not at my desk for more than about 20 minutes I set it to go
into powersaving (CRT off).

Right now, once it actually finishes warming up, the picture is crisp and
vibrant. The CRT has definately had some wear as the brightness and contrast
are set up at 100% and its still not as bright as a new screen, but it is
more than ample to do programming and graphic editing as the colors still
appear pretty accurate and not washed out.

-Dan

 

[DS]

Um, this person is Daniels Stern who resells and advises on automative
lights.

By the way, Sony sets are famous for solder joint problems and
capacitors sometimes depending on models.

Model number please?

Cheers,

Wizard

Nope, I'm not Daniels Stern, and I know next to nothing about auto lights


Its a rebranded trinitron, the exact model is Dell D2026T. HP also had a
rebrand of the identical monitor, and I've noticed a few other people have
been posting to this newsgroup with problems, though I cannot verify if they
are the exact same innards, but most refer to the 20" HP (using trinitron
tubes). Unfortunately I haven't read anyone else having the same problem as
me, others seem to have issues with focus failing or sync errors. I guess
this model is giving up its ghost right about now. All the same, if I can
fix it for a few bucks to have it last another year or two, that would be
fantastic.

Thanks,
Dan

 

[Mark A]

Its a rebranded trinitron, the exact model is Dell D2026T. HP also had a
rebrand of the identical monitor, and I've noticed a few other people have
been posting to this newsgroup with problems, though I cannot verify if they
are the exact same innards, but most refer to the 20" HP (using trinitron
tubes). Unfortunately I haven't read anyone else having the same problem as
me, others seem to have issues with focus failing or sync errors. I guess
this model is giving up its ghost right about now. All the same, if I can
fix it for a few bucks to have it last another year or two, that would be
fantastic.

Thanks,
Dan

Not all monitors with Trinitron tubes are made by Sony. Sony sold the
Trinitron tubes separately (or at least they did until recently) to many
other monitor manufacturers. I still have a 15 inch Nokia (manufactured by
Nokia) that has a Trinitron tube made by Sony.

Of course, Sony could have made the entire monitor (I don't know), but I
know that they sold the tube by itself also. The Trinitron patent has
expired, so there are other manufacturers who now make shadow mask tubes.

I had a Sony 20 inch professional monitor that had similar symptoms as
yours, and it recently went blank. If you live near San Diego (where the
Sony repair facility is) they will repair if for a fixed fee of about $400
(they will probably fix the lack of brightness and contrast also). However,
I recently bought a new high end 19 inch monitor for about $325 that is
extremely sharp and bright. You can get mainstream 19 inch monitors for
about $250.

 

[Mark A]

Not all monitors with Trinitron tubes are made by Sony. Sony sold the
Trinitron tubes separately (or at least they did until recently) to many
other monitor manufacturers. I still have a 15 inch Nokia (manufactured by
Nokia) that has a Trinitron tube made by Sony.

Of course, Sony could have made the entire monitor (I don't know), but I
know that they sold the tube by itself also. The Trinitron patent has
expired, so there are other manufacturers who now make shadow mask tubes.

I had a Sony 20 inch professional monitor that had similar symptoms as
yours, and it recently went blank. If you live near San Diego (where the
Sony repair facility is) they will repair if for a fixed fee of about $400
(they will probably fix the lack of brightness and contrast also). However,
I recently bought a new high end 19 inch monitor for about $325 that is
extremely sharp and bright. You can get mainstream 19 inch monitors for
about $250.

Oops. I should have said (I think):

The Trinitron patent has expired, so there are other manufacturers who now
make aperture grill tubes.

 

[LASERandDVDfan]

The Trinitron patent has

expired, so there are other manufacturers who now make shadow mask tubes.

Don't you mean aperture grille tubes.

And, so far, I only know of at least three manufacturers that make tubes based
on Trinitron, but not totally copying it.

Mitsubishi, NEC, and Viewsonic. But, Sony still makes the best, IMO. No other
CRT uses the LSAGIC electron guns. - Reinhart

 

[Mark A]

The Trinitron patent has

Don't you mean aperture grille tubes.

Yes, I corrected myself in a subsequent post.

And, so far, I only know of at least three manufacturers that make tubes based
on Trinitron, but not totally copying it.

Mitsubishi, NEC, and Viewsonic. But, Sony still makes the best, IMO. No other
CRT uses the LSAGIC electron guns. - Reinhart

You are probably right, but when it comes to computer monitors, technology
investment in direct view monitors has probably come to an end with the
advent of flat panel LCD monitors.

I recently wanted a 19-20" direct view Sony monitor to replace my 20" Sony
that died, but could not even find one for sale. They still make a 21 inch
$1800 professional direct view monitor, but that is way too much money (and
too heavy IMO). I ended up with a 19 inch Viewsonic P90f that is very sharp
and cost about $325. It is not exactly the same as the aperture grill, but
is a hybrid technology.

 

[DS]

Not all monitors with Trinitron tubes are made by Sony. Sony sold the
Trinitron tubes separately (or at least they did until recently) to many
other monitor manufacturers. I still have a 15 inch Nokia (manufactured by
Nokia) that has a Trinitron tube made by Sony.

Of course, Sony could have made the entire monitor (I don't know), but I
know that they sold the tube by itself also. The Trinitron patent has
expired, so there are other manufacturers who now make shadow mask tubes.

I had a Sony 20 inch professional monitor that had similar symptoms as
yours, and it recently went blank. If you live near San Diego (where the
Sony repair facility is) they will repair if for a fixed fee of about $400
(they will probably fix the lack of brightness and contrast also). However,
I recently bought a new high end 19 inch monitor for about $325 that is
extremely sharp and bright. You can get mainstream 19 inch monitors for
about $250.

at one point I had the specs, and I think this tube was made by Sony. There
are many places that will fix it for far less than that amount, but anything
more than $50 really isn't worth it. At this point I'm eyeing a 20" LCD
panel, but they're just too dang expensive for me right now. Thats why if I
can coax this screen to work for another year or two I could probably afford
the 20" LCD. If its just a simple capacitor fix though, I should be able to
do it myself, and thats why I'd like to get any input about fixing it

-Dan

 

[Mark D. Zacharias]

Try adjusting the screen adjustment on the flyback transformer to get a
little more juice from the tube. Ought to work for a while. There's 2
adjustments on a common flyback transformer. One for focus, the other for
"screen". There's probably raised black lettering near each adjustment.
Re-adjusting the focus at this point would probably also help.


Mark Z.

 

[John Del]

Subject: Re: Capacitor on last legs in Trinitron screen

From: "Mark D. Zacharias" [email protected]
Date: 7/25/04 1:29 AM
Message-id: <[email protected]>

A common symptom of Sony tv's as they get older is the PICTURE TUBE cathode
emissions are lower, and the picture is blanked by the microprocessor until
the picture is considered watchable. If the picture is still somewhat
pastel-looking after it comes on, this is your problem, a bad picture tube.

I don't think it's the CRT from his description. He says it goes from black to
normal output in 20 seconds (once it finally starts to light), which is the
normal warmup time of a CRT. I don't know if his Dell is an actual Sony
chassis, but those Sonys come out of AKB blackout immediately.

From his description of the problem, I'd guess that there is no filament on the
tube during the half hour warmup time, and the fil finally lights leading up to
the 20 second warmup. If it were AKB blackout, it would blink on suddenly.
Either there is a problem directly in the filament loop, or the power supply
from which the fil loop derives it voltage is not operating. The OP is going
to have to do some basic voltage troubleshooting to narrow this down.

John Del
Wolcott, CT

"I'm just trying to get into heaven, I'm not running for Jesus!"
Homer Simpson

(remove S for email reply)

 

[LASERandDVDfan]

when it comes to computer monitors, technology

investment in direct view monitors has probably come to an end with the
advent of flat panel LCD monitors.

Even so, I'd rather have a CRT monitor over an LCD. They still can quite
deliver an image that's acceptable, IMO.

It is a pity that it's become hard to locate a Sony monitor that isn't too big
for practical home use, but there are still other choices that are decent for
CRT displays, as you've chosen with a ViewSonic. - Reinhart

 

[Jason D.]

Got a 20" trinitron screen that takes ages to turn on. Everything I read
seems to point to a dying capacitor, probably one of the filter capacitors
being dried up, or some other capacitor in the power supply. If open it up,
how easy will it be to find this capacitor? What should I look for? How
should I go about testing it?

Thanks in advance!
-Dan

Um, this person is Daniels Stern who resells and advises on automative
lights.

By the way, Sony sets are famous for solder joint problems and
capacitors sometimes depending on models.

Model number please?

Cheers,

Wizard

 

[Jason D.]

Nope, I'm not Daniels Stern, and I know next to nothing about auto lights


Its a rebranded trinitron, the exact model is Dell D2026T. HP also had a
rebrand of the identical monitor, and I've noticed a few other people have
been posting to this newsgroup with problems, though I cannot verify if they
are the exact same innards, but most refer to the 20" HP (using trinitron
tubes). Unfortunately I haven't read anyone else having the same problem as
me, others seem to have issues with focus failing or sync errors. I guess
this model is giving up its ghost right about now. All the same, if I can
fix it for a few bucks to have it last another year or two, that would be
fantastic.

Thanks,
Dan

Whoops. Thought this was the guy I saw on other newsgroups.

By the way, every Sony-made monitors I come across that were
relabelled for other OEMs always had chassis number on back that
begins with "SCC-...."

Cheers,

Wizard