I have a Pioneer SX-3800 with distorted sound in the right channel. Injecting a 100Hz tone gives the best-looking waveform results, which shows some clipping on the negative-half of the waveform. I only see clipping when there is a load across the output (speakers connected) - with no load, the waveform looks normal. I started the procedure for setting the 0 volts and idle current on the amplifier board according to the service manual. The left channel set up fine, but the right channel gave me some issues (no doubt related to my bad waveform). I was able to set VR2 for 0v, but was unable to set VR4 to 120mV - I could only get about 5mV out of it. I didn't even try VR6. Is there a common failure component to look for here? I'm trying to avoid having to pull components to hunt this down. Thanks!