Right Channel of Amplifier Much lower than Left

It may or may not mean anything. Over time, some shrink sleeves just shrink more. Caps themselves, even if failing, rarely get hot. The entire unit might get hot due to bad ventilation. People tend to put things in places that block airflow. Or, bias could be too high and things are just running hot. Quality name brand sleeves don't usually shrink, but some off-brands may be more prone to it.

Anyway, I do most of my testing with nothing more than a good DVM. Good means that it will have a reliable diode check function so you can check diodes and transistors for basic function. Most of the time, if they pass the simple diode test, they're fine. I do most testing power-off. First, in diode check mode, check every diode. Plus lead on the non-band end, minus lead on the banded end. You should see a reading of 0.6 volts or so. If zeners pass this test, they're likely good too. Next, in same mode, check all transistors. There are much better instructions here than I can write in this post. Try @EchoWars excellent stuff here- http://audiokarma.org/forums/index.php?threads/bipolar-junction-transistor-testing-basics.43186/

You can test most small signal transistors in-circuit, but readings for output transistors can be confusing or useless due to low value resistors in the area. We'll cross that bridge when we come to it.

If that all looks good, move on to resistors. Remember that nothing can make a resistor look higher than it's value (unless the circuit has residual voltages present). If values are high, the part is likely bad. If low, you're probably seeing something in parallel. Resistors rarely fail low.

If mysteries remain, clip to the chassis and check ground points. If you have to resort to power-on testing, start with supply voltages on both sides of the fuses.
 
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