I had the TX-NR1000 off and disconnected for two weeks while on vacation to protect it from power surges and such. When I reconnected the receiver,it worked fine for a couple hours and then the sound went away while watching/listening to Sat TV. The receiver remained on and all switching functions worked, only no sound (not even the test tone) from any source and to neither A or B speakers. I turned it off and on and sound came back for a minute and then it was gone again. On my second try it didn't come back at all. IF I set it for Direct Audio there is sound. So it would seem that the problem is in the DSP, what do you think? I have already tried: disconnecting all speakers and external sources, initializing the receiver, letting it connected for a couple of days, disconnected for a few days... I do have the Service Manual in case you want to point me to a section in there. Thank you! My receiver only remembers its settings when connected to a UPS and the power outage does not deplete the somewhat small UPS.

Audio Players & Recorders - Onkyo - TX-NR1000 Receiver