Since I posted this originally, the sticking keys problem went away but the FILL (MAIN) buttons have gotten worse. The C and D fill buttons are almost impossible to activate. I'm going to have to take it apart. But before I do, I thought I'd resurrect this in case anyone wants to say NO DON'T DO THAT.
Hopefully, I can open it up and if it looks like it's over my head, I can just reassemble it and no harm done. My aim is to do the WD40 trick Tom mentioned.
------------------
Bill
Yamaha PSR2000
_________________________
~ ~ ~
Bill