Advice / Schems on a General Electricrp 1561a

[samelliot]

Sorry the title got messed up. Its a rp 1561a model.
So I bought this for a couple bucks at a church rummage.
When you plug it in, all it does is buzz/hum at a constant rate, and moving the volume adjustment does not change the volume of said buzzing.

Anyone know where to start?
Need a schem too.
Looks like the guy in the pic.