NEC MultiSync LCD1700M Power Supply Problem

[Randy Thompson]

Hi, all!

I'm looking for some more information on an NEC Multisync LCD1700M power
supply problem. Preferably a schematic on the power supply itself.

When I first got the unit, the monitor would attempt to power on and then
shut down. The power LED would blink and you would hear a popping sound
from the built-in speakers.

I opened the monitor up and took a look at the power supply.
Physically, the following capacitors in the secondary of the supply were
bulging and/or vented - C701, C702, C704, and C713 - and have since been
replaced. The popping sound has gone away, but the supply
voltages/power LED continue their bounce.

The power supply appears to be made by Acer. "Acer Communications and
Multimedia" are printed just above the switching transformer. In the
center of the circuit board on the copper side is the number
"48.L1404.A10". Searching for this number yields nothing. There is a
bar-coded sticker with the following information:

"55L0704D21AD5151S00772 XD763"

If anyone has any information they could pass along on this monitor and/or
problem, it would be greatly appreciated!

Thanks,
Randy

 

[dahawaiian]

Hi Randy,

I have the same problem. Have you been able to get help with this yet?
or are you still waiting? If you have and info could you please pass i
on. Or if anyone else has information on this problem, can you pleas
send me any info you have. Thank you in advance for any and all hel
you have.

Al,

 

[me]

snip

Off hand I would suggest checking the diodes that feed into the
capacitors, since the caps were likely to have shorted they may have over
heated them...