Onkyo Tz Tz 840 Hybrid standby light flashing

Can’t get a universal remote to connect. I have tried a rca and a onkyo remotes

I purchased an Onkyo TX-SV343 Receiver (w Phono input) at a Salvation Army store for $30. I want only audio output, I don't have a TV, so I don't need video output. When I got it home, it remains in 'standby' mode. The tuner and other mode selection display doesn't light up. When I went online, there was a pertinent video of a guy in England with the same problem on an Onkyo unit, . He found that a transistor Q9002 was dysfunctional and preventing a CPU control a signal to tun on the main power transformer. He said it could have been a relay or other part, but he was able to fix the problem ('the easiest fix I've ever done') by soldering a wire from the transistor to the relay to the transformer. I'm not an electrician who can read circuit maps; I'd like to know the best way to approach finding the problem without spending $100+ for diagnosis. I don't need video from this receiver, just stereo and CD and Phono.

Onkyo receiver TX-8511 no sound

Onkyo TX-NR656

I have an Onkyo HT-R758 AV Receiver that when I turn it on will then turn right back off on its own. I have switched power outlets and this is with all of the wires disconnected from the unit.