Help Finding Replacement Parts

I had the exact same problem with the channel/volume autoshifting. I found a electronic firm that would rebuilt the board for $185.00 plus shipping-----screw that. I cut the plastic hold down nubs on the channel/volume buttons itself and disassembled the contact. Inside the button was a copper metal disc showing arc tracks and "carbon scoring" on the underside. I just removed the button guts and now use the remote for channel and volume adjustments. So far the power button still works for me. I may try buffing and cleaning the disc and contacts later, but what the hey, I'd rather surf with the remote from the couch.