"mike" wrote in message
...
I picked up a free LG W2252TQ-TF.
lights up for a second then quits.
Figgered bad caps, but I pulled and tested 'em all.
All good. No bulges.

Checked all the diodes. Other semiconductors aren't
shorted. Two fets in the backlight supply probably
have the highest stress level, but I thought I'd
ask for ideas before trying to get them out.

It's gonna be difficult to power it up disassembled.

Ideas on other possible high failure rate parts?
Schematic?

Thanks, mike


Backlight tube itself ? Most of the lamp inverters that I've seen, have
current monitoring. If a 'wrong' current caused by a defective tube is
detected, the inverter just shuts down. It makes them hard to troubleshoot
without an appropriate load. You can check that the supply voltage stays up,
and that the 'on' signal to the inverter stays asserted. I've had a couple
of the high voltage tube coupling caps fail over the years, and also
transformers. You can make sure that the backlight itself has quit, and it's
not just that the screen has gone black, by shining a powerful light at the
front of the screen, at an angle. Usually, you will be able to see at lest
some vestige of what should be being displayed, if it *is* that the
backlight has gone out.

Arfa