I've got a Logitech G51 on my home PC, and just today it started producing loud, constant feedback to any speaker that is plugged into the right-surround RCA jack. I thought maybe ESD was causing it, so I unplugged it for a while and plugged it back in, same thing. Could the PCB for the sub/amp have gone bad, or maybe a bad solder joint? Doesn't matter which of the 5 speakers I plug into that port, it always produces the white noise feedback. It's unplugged for the time being.