It seems this 19" LCD won't start up when it is cold. If you leave it
for a bit then it will eventually start up. The customer reported that
it had a swimming effect, but I did not see that happening. I did notice
that the backlight seemed to dim and brighten on it's own once in a
while.

I'm assuming that the CCFL tubes or the inverter are the cause of the
dimming, but the startup problem is weird. The screen blinks the LED and
you hear a high voltage like squeak and the lcd flashes bands
momentarily, but no pic or menu is displayed. After it gets warmed up,
it will run for days without incident.

I really hate to throw this one out without trying to solve it's
problems. It's a 2005 model.

Any ideas out there?

- Tim -

"Tim" wrote in message
...
It seems this 19" LCD won't start up when it is cold. If you leave it
for a bit then it will eventually start up. The customer reported that
it had a swimming effect, but I did not see that happening. I did notice
that the backlight seemed to dim and brighten on it's own once in a
while.

I'm assuming that the CCFL tubes or the inverter are the cause of the
dimming, but the startup problem is weird. The screen blinks the LED and
you hear a high voltage like squeak and the lcd flashes bands
momentarily, but no pic or menu is displayed. After it gets warmed up,
it will run for days without incident.

I really hate to throw this one out without trying to solve it's
problems. It's a 2005 model.

Any ideas out there?

- Tim -

First thing I'd check is electrolytic capacitors in the power supply and
throughout the rest of the monitor. Cold faults are the classic symptom of
bad capacitors, I wouldn't be surprised if you find some of them bulging or
leaking onto the PCBs.

In article cScIj.1006$at6.868@trndny01, says...


"Tim" wrote in message
...
It seems this 19" LCD won't start up when it is cold. If you leave it
for a bit then it will eventually start up. The customer reported that
it had a swimming effect, but I did not see that happening. I did notice
that the backlight seemed to dim and brighten on it's own once in a
while.

I'm assuming that the CCFL tubes or the inverter are the cause of the
dimming, but the startup problem is weird. The screen blinks the LED and
you hear a high voltage like squeak and the lcd flashes bands
momentarily, but no pic or menu is displayed. After it gets warmed up,
it will run for days without incident.

I really hate to throw this one out without trying to solve it's
problems. It's a 2005 model.

Any ideas out there?

- Tim -

First thing I'd check is electrolytic capacitors in the power supply and
throughout the rest of the monitor. Cold faults are the classic symptom of
bad capacitors, I wouldn't be surprised if you find some of them bulging or
leaking onto the PCBs.


Well I got the monitor opened up, and I found 5 jiffy popped
electrolytics, all on the PS board, and all the same value (470uf @ 25V,
made by CapXon). All the other caps look excellent. I'll replace those
puppies, and let you know the outcome. I think I'll try to put in some
with a bit higher voltage, if I can find some that will fit into the
enclosure.

Thanks for the heads up,

- Tim -

"Tim" wrote in message
...
In article cScIj.1006$at6.868@trndny01, says...


"Tim" wrote in message
...
It seems this 19" LCD won't start up when it is cold. If you leave it
for a bit then it will eventually start up. The customer reported that
it had a swimming effect, but I did not see that happening. I did
notice
that the backlight seemed to dim and brighten on it's own once in a
while.

I'm assuming that the CCFL tubes or the inverter are the cause of the
dimming, but the startup problem is weird. The screen blinks the LED
and
you hear a high voltage like squeak and the lcd flashes bands
momentarily, but no pic or menu is displayed. After it gets warmed up,
it will run for days without incident.

I really hate to throw this one out without trying to solve it's
problems. It's a 2005 model.

Any ideas out there?

- Tim -

First thing I'd check is electrolytic capacitors in the power supply and
throughout the rest of the monitor. Cold faults are the classic symptom
of
bad capacitors, I wouldn't be surprised if you find some of them bulging
or
leaking onto the PCBs.


Well I got the monitor opened up, and I found 5 jiffy popped
electrolytics, all on the PS board, and all the same value (470uf @ 25V,
made by CapXon). All the other caps look excellent. I'll replace those
puppies, and let you know the outcome. I think I'll try to put in some
with a bit higher voltage, if I can find some that will fit into the
enclosure.

Thanks for the heads up,

- Tim -

Same voltage should be fine, those caps likely came from the infamous
electrolyte scandal of a few years back. Make sure you scrub off the goo.

"James Sweet" wrote in
news:UhhIj.1995$ie3.1131@trndny02:



"Tim" wrote in message
...
In article cScIj.1006$at6.868@trndny01,
says...


"Tim" wrote in message
...
It seems this 19" LCD won't start up when it is cold. If you leave
it for a bit then it will eventually start up. The customer
reported that it had a swimming effect, but I did not see that
happening. I did notice
that the backlight seemed to dim and brighten on it's own once in
a while.

I'm assuming that the CCFL tubes or the inverter are the cause of
the dimming, but the startup problem is weird. The screen blinks
the LED and
you hear a high voltage like squeak and the lcd flashes bands
momentarily, but no pic or menu is displayed. After it gets warmed
up, it will run for days without incident.

I really hate to throw this one out without trying to solve it's
problems. It's a 2005 model.

Any ideas out there?

- Tim -

First thing I'd check is electrolytic capacitors in the power supply
and throughout the rest of the monitor. Cold faults are the classic
symptom of
bad capacitors, I wouldn't be surprised if you find some of them
bulging or
leaking onto the PCBs.


Well I got the monitor opened up, and I found 5 jiffy popped
electrolytics, all on the PS board, and all the same value (470uf @
25V, made by CapXon). All the other caps look excellent. I'll replace
those puppies, and let you know the outcome. I think I'll try to put
in some with a bit higher voltage, if I can find some that will fit
into the enclosure.

Thanks for the heads up,

- Tim -

Same voltage should be fine, those caps likely came from the infamous
electrolyte scandal of a few years back. Make sure you scrub off the
goo.




he probably should use low ESR,105 degF switcher-grade caps,too.

--
Jim Yanik
jyanik
at
kua.net

he probably should use low ESR,105 degF switcher-grade caps,too.



Won't hurt, though I think people obsess over the 105 degree (it's C, not F)
thing, if anything in a monitor is approaching 100C, something is wrong.

yup seen this in power supplies- motherboards.
the caps that come from china i call them
chinese crackers.

"Tim" wrote in message
...
It seems this 19" LCD won't start up when it is cold. If you leave it
for a bit then it will eventually start up. The customer reported that
it had a swimming effect, but I did not see that happening. I did notice
that the backlight seemed to dim and brighten on it's own once in a
while.

I'm assuming that the CCFL tubes or the inverter are the cause of the
dimming, but the startup problem is weird. The screen blinks the LED and
you hear a high voltage like squeak and the lcd flashes bands
momentarily, but no pic or menu is displayed. After it gets warmed up,
it will run for days without incident.

I really hate to throw this one out without trying to solve it's
problems. It's a 2005 model.

Any ideas out there?

- Tim -

In article UhhIj.1995$ie3.1131@trndny02,
says...


"Tim" wrote in message
...
In article cScIj.1006$at6.868@trndny01, says...


"Tim" wrote in message
...
It seems this 19" LCD won't start up when it is cold. If you leave it
for a bit then it will eventually start up. The customer reported that
it had a swimming effect, but I did not see that happening. I did
notice
that the backlight seemed to dim and brighten on it's own once in a
while.

I'm assuming that the CCFL tubes or the inverter are the cause of the
dimming, but the startup problem is weird. The screen blinks the LED
and
you hear a high voltage like squeak and the lcd flashes bands
momentarily, but no pic or menu is displayed. After it gets warmed up,
it will run for days without incident.

I really hate to throw this one out without trying to solve it's
problems. It's a 2005 model.

Any ideas out there?

- Tim -

First thing I'd check is electrolytic capacitors in the power supply and
throughout the rest of the monitor. Cold faults are the classic symptom
of
bad capacitors, I wouldn't be surprised if you find some of them bulging
or
leaking onto the PCBs.


Well I got the monitor opened up, and I found 5 jiffy popped
electrolytics, all on the PS board, and all the same value (470uf @ 25V,
made by CapXon). All the other caps look excellent. I'll replace those
puppies, and let you know the outcome. I think I'll try to put in some
with a bit higher voltage, if I can find some that will fit into the
enclosure.

Thanks for the heads up,

- Tim -

Same voltage should be fine, those caps likely came from the infamous
electrolyte scandal of a few years back. Make sure you scrub off the goo.



OK I replaced the bad caps. There wasn't any goo on the PCB at all. The
final count was 3 x 470uf 25v and 2 100uf 10v. The ones I had were a
higher voltage, but they fit ok. The monitor came right up and seems to
be fully functional. I am using it as my shop monitor right now.

Thanks for your help, James.

- Tim -

James Sweet wrote:


he probably should use low ESR,105 degF switcher-grade caps,too.


Won't hurt, though I think people obsess over the 105 degree (it's C, not F)
thing, if anything in a monitor is approaching 100C, something is wrong.


Obsess? No. Read the capacitor manufacturer's specifications: 1000
hours life at the rated temperature. If you chose a lower temperature
part it will work, but have a lot shorter operating life. How many
times do you want to repair something for the same problem? Would you
like to recap or replace a computer motherboard every couple months, to
a year? Also, as the ESR starts to rise, the electrolytics generate more
internal heat. Operating temperature is a complex issue. Ambient
temperature, airflow, dust buildup, component spacing all affect the
capacitors. Use low temp parts if you're cheap, but use better parts if
you want them to last.


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