I just moved to Chicago during the worst blizzard in 30 years or so. My moving truck got snowed in and my k2000s with it. It sat in sub-freezing temps for 5 days. I let it thaw a couple of days before trying it, but now I get some high-pitched tones in the background with many of the patches. Sometimes the tones hold well after the patch sound has decayed. Can anyone tell me how bad a problem I have and how much it might cost to fix?

try doing a hard reset if that doesn't work run the self diagnostics. this will put the k2000 into a known state. be shure you have a blank disk in the drive. check your manual for details. If it doesn't clear you should take it in for repairs.