Hello - I purchased my 7125 new in 2005. It's been a great Amp and has just now started to show its age. The center channel has a constant "buzzing sound" coming from it. I switched the speaker connection to another speaker and confirmed its the center channel. I'd like to repair it but have had NO LUCK in finding a schematic for this model anywhere. HELP?

Thanks!

A schematic would be more helpful if you had a scope to follow the signal path. You can check voltages from input to output with a multi-meter. With a scope and meter, you can always use one of the "good" channels as a reference for the voltages and also compare the audio signal readings with the scope.