From your post #18, I'm suspecting a ground loop between the PC and the rest of the system. Could be a faulty surge suppressor or UPS box, or even a house wiring issue.
Without rereading the whole thread, have you unplugged the satellite feed from a receiver, and has that cured it? If so, I'm on the right track.
Without rereading the whole thread, have you unplugged the satellite feed from a receiver, and has that cured it? If so, I'm on the right track.
