This sounds more like a static charge buildup issue, which affected input ports, esp. HDMI.\n\nInteresting, as @Replicant 7 mentioned that all HDMI inputs were lost. I wonder whether usb audio and analog inputs would still continue to work or static charge build-up fools entire board. Can we isolate the issue to HDMI inputs only? @Replicant 7, did you have any analog\/usb audio inputs connected to AVR at that time or just HDMI? \n\nSimilar things can happen on PCs if left turned on for days. Some apps, commands or connections may start to glitch a bit. Simple restart usually restores normal functioning, or unplugging and plugging back cable to restore connection handshake.\n\n\nClearly, there's enough power in standby mode to keep the AVR in a wonky state once it enters that state. That is why they need to be unplugged. If it were static buildup, unplugging the AVR would not clear the static charge since there is no path to ground. Its not a static buildup.\n\nAlso true, if there was no ground loop before the incident. @Replicant 7, did you ground your AVR before the issue emerged?\n\nMy 8 year old Yamaha has never experienced total lost of audio, so I have not done hard power cycle. But I needed to unplug HDMI cables and plug them back in on rare ocassions for devices to be re-recognised. AVR is set to go to stand-by every day 15 minutes after the last connected device is off.