Blown Photocoupler

[gustav]

I recently replaced my power supply board and the photocoupler blew its lid. Replaced it with another one from the orginal board and now no power or power light. On the output pins, there is no voltage showing on the PSON. So far, the fuse tested good, and getting dc voltage from the big cap.

During the testing phase of the new board, the metal cover was loose and may have shorted the board, thus blowing out the coupler. That's one theory. Of course there might be other reasons for the blowout.

Any suggestions from the wise and experienced would be appreciated.
Thanks

[PlainBill]

Re: Blown Photocoupler

I recently replaced my power supply board and the photocoupler blew its lid. Replaced it with another one from the orginal board and now no power or power light. On the output pins, there is no voltage showing on the PSON. So far, the fuse tested good, and getting dc voltage from the big cap.

During the testing phase of the new board, the metal cover was loose and may have shorted the board, thus blowing out the coupler. That's one theory. Of course there might be other reasons for the blowout.

Any suggestions from the wise and experienced would be appreciated.
Thanks

Trace the circuits and replace any defective or damaged components.

PlainBill

[gustav]

Re: Blown Photocoupler

The monitor is toast. DOA. Opened up the screen panel today and two of those film thin ribbon cables were torn. Someone had pryed open the metal casing using a screwdriver ripping them. No sense in pursuing this endeavor anymore. At least, I could have sold the panel, but now that's not happening.

Thank you all for the site and sharing your wisdom

[momaka]

Re: Blown Photocoupler

In that case, open up the panel and scavenge the CCFLs. You never know when you'll run into a monitor with bad ones. They can be also very useful when testing an inverter of another monitor.

[gustav]

Re: Blown Photocoupler

Thanks momaka. I calmed down and decided to continue to work/play with the board abit more. And your right. There are some parts in there, since it is a 28", that will be of some use. This is a golden opportunity to learn more of the circuitry without the pressure to get it right. I am sure in the near future, there will be a broken lcd up for sale that's cheap and will be easily repairabel. The glass is half filled.