I was having scratchy/low volume output on the left channel, but this cleared up or had intermittent issues by turning the volume knob up and down. I haven't been using this much for the last few months, so though, no big deal, clean the volume pot with deoxit and turn the knob a bunch of times. So, I removed the bottom cover, face, and all the screw to slide the board down through the chassis to access the volume pot. I sprayed Deoxit for faders onto the contacts and turned the knob through 40-50 full sweeps, and put everything back together. Now there is NO volume in the left channel. lol. Back story, this was recapped about 5 years ago, and I put a TxTurbo power supply board in this about a year ago. I'll be checking out some voltages over the weekend, wish me luck.