Blown Peavey Supreme

peavey_front.jpg


Back in November, I built up the Little Gem audio amplifier, and toyed around with it for a little while before I listed it on Craigslist to see if I could make a few bucks on it. Before it sold, somebody in my area saw the ad and contacted me to see if I'd be interested in a Peavey amp head that stopped working. He couldn't get it to work, and after replacing a fuse in it, he said it "started smoking," so he didn't want to mess with it anymore. I took it, figuring that at best, I'd be able to fix it and sell it, and at worst, I'd have a bunch of nice knobs and components that I could scavenge and use for future projects.

Not wasting any time, I plugged in to see what would happen. No smoke. Good. Next, I tried the pre-amp line to see if the unit was sending any signal at all to another amp, and sure enough, the pre-amp side of the unit successfully shaped the signal, which meant that I had reverb, equalizer, and a couple other miscellaneous features.

Curious about why the power-amp side of the amp head didn't work, I cracked the case open and found this:

burn.jpg


At the center of that wasteland stands three prongs that used to be a transistor (possibly the power transistor), and all around it were burnt out resistors.

Since the pre-amp side works, the amp-head isn't just a boat anchor. It's kind of useful, and it actually sounds better than my fully-functioning amp.

Given the disaster that is the circuit board, what's the general opinion here? Should I try to replace everything that's been burned out, and try to trace down the short that caused the problem in the first place? Or should I just scavenge the thing for parts?