Hi all, I finally found some time to play with another receiver. This will be Pioneer SX-650. Original symptom was - relay clicking on and off. - measured all power supply voltages - all correct - measured all voltages to the power amp board - all correct Right channel DC offset = 0.41V stable. Left channel DC offset is jumping up and down between 0 and ~1V. I can hear something shorting on the power amp board when relay clicks. Measured voltages on 4 pins of the power pack in left channel: * Pins 1/5 = +/- 36V * Pins 2 and 6 - instead of +/- 1.2V , I have the same weird jumping DC on both pins (right channel is solid +/- 1.2V) Would next step be breaking path(s) between 2SA798 and the SP-40W power pack? Thank you.