Hi Spector, and Welcome to Audioholics Forums.
I think that you'd be better off just buying a more recent Stereo receiver at "Audiogon" for very little money that will easily outperform your Onkyo TX-2000.
The money spent trying to fix it will buy you a nice stereo receiver, with much more power and of a much more recent vintage. Check some Yamaha, Denon stereo receiver ones. Yamaha has usually a good tuner section. I'm sure that you can find one at Audiogon for less than $100 or so.
So, not worth it in my book, to try getting it fix.
Regards,
Bob