My yamaha RX-V420 theater. It turns off automatically when I turn it on, at first with a blow it was working but today I don't want it anymore, and I don't want another one ..... I want to repair it myself even if I am old, I am even studying with electronic tutorials by youtube checking retentions, transformers, relay and others but I can't find what the hell it is. when I turn it on, the click of the relay is heard, but after two seconds it is heard again, the click is turned off and it is not the relay because it is already disassembled and tested and makes contact without problems until I remove the twelve volts. help.

The safest thing is that the audio outputs are because what your amplifier does is a sign that they are cut. Greetings!