I have a Denon AVR-2312 , since 10 years..
a very fine amplifier
Last week it went down after 2 minutes to red light flashing...
the it went faster and faster..
Seemed tot be a ASO Failure according to service manual...
tried everything , check speakers and so on.. nothing worked.
So opening and found a superbe article online after quite a while searching...
https://yesthomas.com/Electronics/201702%20Denon%20AVR3312%20Blinking%20LED.htmlthis was my problem.. I put this here.. since it could help someone..
So I repaired it for 15 cents...
Tnx to this guy from Sydney, that I can't address myself to him directly
JP