"James Sweet" wrote in message
news:Y8RXi.2719$bm.1189@trndny08...


First thing you should do is check for shorts across the various power
rails. If a short is found, using a sufficient resolution low-ohms
meter might let you located the offending component. Sometimes the
bypass caps can go short on order gear like this, replace them all if
needed.

Dave.


Second that on the caps, I recently repaired a Volkswagen ECU that had a
shorted electrolytic capacitor, I think that was the first time I'd seen a
lytic shorted, regulator was getting hot which clued me in. I've found
shorted tantalums in several things.


Thirded (thirded ?!) on the caps. A few years back, Panasonic used to use
some purple 10u's in everything they made, and they were swines for going
short. Often used as decouplers around signal processing ICs, so you can
imagine what it was like with whole signal processing stages stopping
working, because a cap on an IC pin, decoupling some internal bias rail or
whatever, had failed ...

These days, I see a lot of shorted electrolytics of all manufacture, on
supply rails in amps and home cinema rigs, and so on.

Arfa