Had this unit come in, and it would shut down (protect) with any audio source connected. Found some bad solder joints on the emitter resistors, resoldered those and everything was OK when I bench tested it. The unit just came back in after a week, and is going into protect again. It will play at low volume fine, but when you turn it up it shuts down, when it does you can watch the protect light flash in time with the beat of the music. No DC bias on the output, nothing abnormal, and if you tap audio off before the speaker relay it sounds fine. Obviously a fault in the protection circuit, however everything checks OK. I traced grounds, checked all components of the protect circuit that I could find without a schematic. Has anyone seen this symptom before? More specifically does anyone have a schematic?
Jammy