Hey everyone, hope someone can help me diagnose a problem I'm having recently with my Pioneer VSX-D509S receiver. Periodically (but not always), after the receiver has been on for some time, I get a buzz or hum throught the speakers. Based on all of the searching/reading I've done through the forum, I don't think its a ground loop. I'm guessing that (unfortunately) its a problem with my receiver that until recently has been perfectly reliable. Possibly pertinent facts about the behavior: 1) This only seems to happen when the receiver is "warm" (i.e. been on for a while). The receiver itself has ample distance from other components, so it shouldn't be "overhot". 2) It doesn't happen EVERYTIME the receiver is warm. (Not 100% repeatable) 3) Happens on every input: TV, VCR, DVD, etc. 4) Muting or changing the volume does not affect the level of the buzz. Whatever it is, its post-power stage in the amp. 5) I've had the receiver for years, this only started happening recently, and there've been no changes in the wiring or setup of the media niche that correspond to the arrival of this problem. 6) The first month or so of this problem, power cycling the receiver made it go away (for a while). Now once the hum starts, it mostly returns right away after the power cycle. 7) The problem has been hard to troubleshoot because it doesn't happen all of the time, so unplugging components, etc. is hard to test cause/effect. 8) The receiver is plugged into the surge protected but not-battery backed section of a UPS along with the DirecTiVo, DVD, VCR, and playstation. (Only the TiVo is battery backed). TV is on its own plug, but I believe its on the same circuit as the UPS. Do people even repair solid state amps anymore? Or is SOP just to junk it and replace these days? Thanks.