Audio Systems: car amp, output transistors, ohm load

Question
Hi Tom, I have a question about a PPI pcx480 4 channel amp I have. I was running it at a 2 ohm load through the rear channel...leaving the front channel unused. A no-no I know, given it is only stable at 4 ohm bridged, but I tested it and it was hitting hard and sounding great w/ no probs...except when hot it would turn off-no sound, then cut back on after it cooled mabe 5 minuits later. I then figured that this would be the only draw back running at 2 ohms....but after about a month the amp finally went up in smoke-literally. Now it is inop. I removed the back cover plate to inspect and there are several diodes (i think) that are burned up...I want to know your opinion...I am a professional car tech (10 yrs) and have plenty of soldering and electical experence, but I have never repaired an amp or audio device...also, I do not want to get hosed at a repair facility. I am confident I could fix it but I dont want to make a fatal mistake.. My question is should I take it somewhere or should I try it myself? Also, if I do it myself (which I would love to do anyway) where can I get parts? Thanks for you time.

Answer
Tim,
The parts that are burned up are they mounted under a metal clamp/heat sink. If they are they are most likely either the output transistors or the power switching transistors. Take a look at the numbers on the burned up parts and let me know. I can look up the part numbers and give you same idea on the cost of the transistors.


TOM,
T&D ELECTRONICS
tdeser@zoominternet.net