to me it sounds like the startup relay has gone bad. Perhaps you can find a service manual online. Alternatively plug the amp into a power sensing surge protector and have the amp come on with the TV or some other device.

If you are confident enough , get he manual and locate the power on relay. Remove the top cover of the receiver and tap on the relay while trying to power it on.

Richard
Service Manual

Similar issue

DOG is GOD spelled backwards.
What others think of me is none of my business.
M80 V3 MY GLOSS Cherry