Kef 200c right tweeter is silent, how to fix it?

After storing my Kef 200c in my basement for a while, its right passive tweeter turns silent after I reconnect it today. Is it too damp? Needs drying up? Can the problem be reversed or fixed? Physically, it looks alright to me. The central active tweeter and left passive tweeter work perfectly. Can anyone shed some light on it?
Check the wiring on that tweeter. If not soldered because of the dampness some corrosion may have occured.