Carver receiver hr-895 one channel noise

[powerdoc]

I bought this receiver very inexpensively because the right channel has an intermittent scratching sound with occasional louder pops. Seems to get somewhat worse as the unit warms up then it stabilizes to it's usual noise It is unaffected by the use of the balance control leading me to believe that it's in the farther end of the power amp. Has anyone worked on this unit or has any good info on what the most likely component to be the failure? Working on this is incredibly difficult as it is built like one of these Chinese puzzles that require removing one part to get to a second etc etc etc so I was hoping I didn't have to reinvent the wheel here. Any help? thanks !