Marantz SR6015 goes into protection mode. 0.5 second red flash

[Don7070]

Hello. This is my first post. I have done a lot of searching. Trying to fix my Marantz SR6015. When I turn it on, it has two different clicks and goes into 0..5 second protection mode. I tried the factory reset. Nothing is connected to it.
I read a thread about an SR8015 and thought I could fix it after reading that, but they are different. Anyway, it seemed like I needed to replace the bridge rectifier, which I did to no avail. Same problem. I also read that the eco relay goes bad on these, so I got one of those too. I don't know which one it is. There are at lease 8 relays. I don't know a lot of technical stuff as far as diagnostics, but I can work on a circuit board. Its current state is about 75 percent disassembled. Please help point me in the right direction. Thanks.

 

[Beave]

Have you seen this from Marantz?

https://manuals.marantz.com/sr6015/NA/EN/DRDZSYmxzbghkd.php

Power turns off and the power indicator flashes in red approx. every 0.5 seconds​

Check the speaker connections. The protection circuit may have been activated because speaker cable core wires came in contact with each other or a core wire was disconnected from the connector and came in contact with the rear panel of this unit. After unplugging the power cord, take corrective action such as firmly re-twisting the core wire or taking care of the connector, and then reconnect the wire. link

Turn down the volume and turn on the power again. link

This unit’s amplifier circuit has failed. Unplug the power cord and contact our customer service center.

 

[Don7070]

Have you seen this from Marantz?

https://manuals.marantz.com/sr6015/NA/EN/DRDZSYmxzbghkd.php

Power turns off and the power indicator flashes in red approx. every 0.5 seconds​

Check the speaker connections. The protection circuit may have been activated because speaker cable core wires came in contact with each other or a core wire was disconnected from the connector and came in contact with the rear panel of this unit. After unplugging the power cord, take corrective action such as firmly re-twisting the core wire or taking care of the connector, and then reconnect the wire. link

Turn down the volume and turn on the power again. link

This unit’s amplifier circuit has failed. Unplug the power cord and contact our customer service center.

Thanks for the reply. Yes I have. As stated, nothing is connected, tried factory reset, replaced bridge rectifier. I know that it has a bad component, I just need to be pointed in the right direction. Thanks again.

 

[Beave]

It seems you're replacing parts in the receiver's power supply, but the notes from Marantz indicate it's likely a problem with the amplifier circuitry. That would probably mean the transistors that are thermally connected to the aluminum heatsink, or it could mean other parts associated with those transistors.

 

[Don7070]

You're right! I actually found out on ChatGPT. I have never used it before today. I found two transistors, and one small one in between them are shorted. I'm impressed and appreciative for your knowledge and response. I know that those are part of the problem. I hope that they are the only problem. It's a helluva lot of work to get to them. Thanks again!