patterncrab
New Member
A coworker recently gave me a pretty beat up M-65 with all of the speaker terminals broken off. After wiring the "A" output directly to the one remaining intact terminal block and capping off "B" and "C", I inserted the amp into a system. With the top cover off, I detected a squeal from the power supply area that sounds like 60 hz. There is no noise present at the speaker, and the squeal is constant and rather high-pitched. The amp sounds okay, but not like a Yamaha. The amp shows signs of having been run hot, but I cannot see any damaged circuitry. Does this sound familiar to anyone? I know just enough about electronics to get me into trouble, and would appreciate any input.