John, I agree with Solomon8's suggestion re: "reseating the cables."
 "Reseating the cables" has resolved a lot of my keyboard malfunctions.
   As mentioned...it's just a case of getting to the cables that might be a mini challenge for the KN7000.
   I have lived in Florida now for 42 years.. and I think we here in the humid climate [Florida] are even more prone to oxidization issues on cable contacts/connections.
   Ron, in Vero Beach Florida
If it were the contact strip I doubt they would all wear out at once.  I had the keyboard stop responding with a instrument.  I opened it up and reseated the cables that went to and from the keyboard and the motherboard.  That fixed it for me.  This could be a easy fix if you are comfortable taking the instrument apart.  If not, then definitely find someone to service it.  Wishing you the best of luck on the repair.