hi all - I have a wk-7500 that has served me well in all the time I have owned it and I relly think it is a good machine. That saidl, just today while playing I found that I wasn't getting full key(s) response when chording with my left hand. Specifically, when key B3 is depressed I get no tones (noise) from keys C3 through F#3. Also, and this is a bit hard to explain, if B3 is depressed ( it sounds ) and held down the aforementioned keeys do not sound - singly or in combination - but if they are held down and the B3 key is then released they ` do sound, although apparently the touch respnse is not effected since no matter what pressure is applied to the key(s) the volume of the note(s) is constant. nAll other keys seem to be working normally. Any thoughts would be appreciated.