The bad part! Probably in the output section. If it has a preamp out try runing out of that and see if works. If it does then it's probably in your output. It could be as simple as cold solders. What do they look like? Are they shiney or dull and lifeless? Look at the caps and see if you see any swollen ones. But, just because they are not swollen doesn't mean they are good. Look at the resistors and see if one cooked the board. If the board is discolored at a resistor check it. That's really the first thing you do is have a good look at it. It could be in the power amp section too. You'll have to do some trouble shooting to narrow it down.

Dave

Thanks, Dave. I'll take a look at the inside of the thing.