Sony TA-N77ES gets hot and right channel fades out?

[ATN]

Hi.
Just purchased this after years if hunting.
The unit runs hot and the right channel fades out... Leaving it to cool down it works again.
Could it be the DC offset or the Bias that needs to be adjusted?

 

[Binkman]

Bias that needs to be adjusted?

Possibly... may need other work if never serviced.
manuals and service bulletins:
https://www.hifiengine.com/manual_library/sony/ta-n77es.shtml

forum search results.
https://audiokarma.org/forums/index.php?search/55922113/&q=Sony+TA-N77ES&o=date