An amp like that has about 125~150 components and several of them could make it do what you're describing. However, your analysis is probably correct. It probably got a good shake-up. This is an older amp. Older electronic equipment needs periodic maintenence. If you're handy with a soldering iron go thru it carefully and touch up suspect-looking solder joints (amp unplugged from AC source (the wall) and filter caps discharged) and there a good chance you'll find your problem. Otherwise, tech-time!
Bob M.[This message was edited by Bob Metzger on 01 October 2002 at 10:26 AM.]