I have a Sony STR-7065 that had bias issues when I got it. I ended up replacing most of the resistors in the amp/power board and then ended up replacing all caps and diodes. Output transistors and thermal compensating diodes check out okay.
I also replaced two of the driver transistors and checked all others. While the bias seems to be back in line I still have a slight power hum and now the Right channel sound level is low vs Left (voltage off of large filter caps is about 58v so a little high). I also noticed that when I powered off I still felt what seemed like a "charge" on the faceplate. I unplugged and that seemed to go away.
I'm going to recheck my solder joints but also wanted to see if anyone on here had thoughts/suggestions? Do I potentially have a grounding issue I need to address? I appreciate any suggestions.
I also replaced two of the driver transistors and checked all others. While the bias seems to be back in line I still have a slight power hum and now the Right channel sound level is low vs Left (voltage off of large filter caps is about 58v so a little high). I also noticed that when I powered off I still felt what seemed like a "charge" on the faceplate. I unplugged and that seemed to go away.
I'm going to recheck my solder joints but also wanted to see if anyone on here had thoughts/suggestions? Do I potentially have a grounding issue I need to address? I appreciate any suggestions.