This has happened to me with two PSR2000s and two PSR2100s that I owned. Maybe I pressed the buttons harder than some other people, or I am unlucky. In any case, get this fixed because any day now, the buttons won't work at all.

The first time, I brought the keyboard to an authorized service center. It was far away, I was without my keyboard for over a week, and I had to pay $25 extra for a rush fee.

I recommend you should do something akin to what I did: I know a high school aged young man who is brilliant with electronics. He bought the highest quality contact switches and soldered them on. I never had the problem again with that button. He charged me $10 an hour, and for $20 I got my keyboard fixed in days.

It is a rudimentary problem to fix for someone who works fixing electronics. You might want to reconsider the authorized service center - especially if the keyboard is out of warranty.

Beakybird