SR5008 Thermal protection fix

My Marantz SR5008 receiver was shutting down due to a thermal protection error. It took me a long time to properly diagnose this failure, because it was sometimes shutting down after only a few seconds, sometimes after a couple of minutes, and sometimes it was functioning properly for a few days.

You can manually bypass the protection circuitry by pressing power+display+status+sound mode. 'Protection pass' is displayed, and everything was working fine. However, this is not a solution, so I tried to figure what the problem was by disassembling the amplifier-radiator module (7ch amplifier).

I measured the PTC resistors, and there was some variation, but I was not sure if replacing them would solve the errors. After reading another post on this forum about a similar amplifier (denon x1200w), I decided to disable the thermal protection for ever.

See attachment where to break the lines on the PCB of the amplifier module. Caution: you have to break/stop lines on both sides, so you have to desolder the power transistors. Of course, your amplifier is not protected against overheating, so only perform this operation if all other options failed!

After this has been done, no thermal protection errors, and my amplifier has been fixed!! 🙂

If you have any questions please send me a PM.
 

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SR5009 Protection Pass

Hi you can disable the protection circuit in a SR5009 by:
Having SR5009 in standby (Solid red light on)
Hold down Dimmer, Status and Sound mode then press the standby/power button. 'Protect Pass' will come up on the screen. You can now let go of the buttons
As mentioned above this is not a permanent solution
 
I am having a simliar problem with a Denon AVR-X4000. After turning off the protection mode it has run fine for several days. Why is this not a goo long-term solution? I am not up for tearing into it and unsoldering parts. Does protection go back on after unit is unplugged or power goes off?
 
I am having a simliar problem with a Denon AVR-X4000. After turning off the protection mode it has run fine for several days. Why is this not a goo long-term solution? I am not up for tearing into it and unsoldering parts. Does protection go back on after unit is unplugged or power goes off?