Adcom GFA-5500 Hum

[slovell]

I'm getting a low ocillating mechanical hum from my 5500. There is no hum or noise coming through the speakers. What might be causing this?
Regards, Sam

 

[Binkman]

Greetings; Its usually associated with the power supply transformer 50 or 60hrz hum. If you can stick an ear to the area around the transformer you'll pin point it. It would seem that that transformer would be quiet, though. (A wooden dowel or a tube from a paper towel roll makes a good stethoscope.)

Looking at a photo of the top cap mounting plate, that could be the source.. maybe tighten that down. If it is the transformer perhaps an insulator is needed.