Hey,
you'll be glad/disapointed to know that I have the same issue as you!
I have a KN2000 and the motherboard of the pitch bend and mod wheel had snapped. This causes my keyboard to be out of tune and the modulation wheel is constantly on about 75%... very annoying! I opened it up and glued the motherboard but still no good. It's pretty clear that I need a new motherboard or PCB or whatever they're called.
It's been giving me a really unique tone that cuts through really well so i'm really keen to get it fixed.
As you know, they don't make the parts anymore, however, I did see a KN2000 on ebay recently. I think it's been sold though! Mind you, it cost about US$400 which is too much to pay just for one little part.
WHAT TO DO>?!?!