Just to be clear, I’m a relative noob to diagnostics, but I read every thread I can where people are trying to track down trouble. With blown outputs, I see two strategies:
1. If no visible damage, start pulling and testing transistors from right to left on the schematic. You are looking mainly for shorted transistors. If you find a bad one, check the next one upstream. These things can take out several components downstream when they short. Of course, the first transistor to fail could be the problem, or it could have gone because of a nearby passive component.
2. If the other channel is good, you can test voltage at the transistor legs on the good side and compare to the bad board. Caution - don’t just poke around with a red probe while the unit is running. Bad things happen. Either use mini grabbers that you insert while turned off, turn on to measure, and turn off to remove, or (a bit more dangerous) cover your probe with electrical tape all except the very tip to probe while unit running. Either way, go right to left on the schematic, measure 3 legs of a transistor on the good board, and then measure same on the bad board, looking for areas where an expected low voltage is very high. That will be a bad transistor, but, again, it may not be the origin of the problem. Hopefully others will chime in and give you more focused advice. Good luck!
