Year-old Samsung 50" Plasma - No Power

[drussell]

Originally Posted by Celt

Yes...check power supply voltages first...and look for bulged caps.

It's unlikely to find bulged capacitors in such a low-hours set. Generally if a capacitor that new dies, it shorts or opens without any external physical symptoms. (He also stated that he didn't see anything burned/fried so I would think that includes crusty capacitors.)

YamahaFreak:

I also forgot to mention, check the obvious, like fuses... The main AC input fuse must be good to be getting the red light but there are usually at least a couple small surface mount ones on the logic board.

Speaking of the logic board, Samsungs usually have a green LED on them. What is yours doing? It should sit there and flash with a period of about once per second if everything is normal.

The problem with this one here turned out to be a couple of shorted FETs (actually IGBTs, but whatever) on the Y-Main board... I'll have to order some from Digikey tomorrow since they are fancy super-high-current (220A), high speed switchers specifically designed for use in pulse applications in PDPs (like the ERC) so none of the usual stuff I have laying around is going to come even close to surviving in that circuit.