Re: ACER 1916B LCD Monitor won't start when cold

"James Sweet" <jamessweet@xxxxxxxxxxx> wrote in
UhhIj.1995$ie3.1131@trndny02:">news:UhhIj.1995$ie3.1131@trndny02:



"Tim" <tim@xxxxxxx> wrote in message
news:MPG.225b5afdceee8a5b9896e8@xxxxxxxxxxxxxxxxxx
In article <cScIj.1006$at6.868@trndny01>, jamessweet@xxxxxxxxxxx
says...


"Tim" <tim@xxxxxxx> wrote in message
news:MPG.225b3030de70bc7d9896e7@xxxxxxxxxxxxxxxxxx
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
.

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