I have a Kurzweil Stage Piano Model 76. It needs repair, but I cannot find anyone who knows much about it here in Kenya.
The problem which has been developing over some years is as follows:
Several notes no longer sound properly - they either give half-sound, no sound, or full-volume sound when lightly touched.
This problem has been getting worse in recent months.
What I do to try to fix it is as follows:
I open the piano and remove the two large, long, narrow printed circuits and and rubber connectors (on which the keys press to sound notes) I then clean the connection points - scrape off carbon etc. This seems to work for a while, however gradually the problem recurs.

I have also purchased new rubber connector strips (correct ones) and installed these. Again the problem seemed solved for a while, but it then recurred.

I note the following: when I screw back the two printed circuits and attach the rubber connectors (and of course connect the cables) and then press on the rubber 'buttons' (at the point where the keys strike the rubber), I get a correct sound from each note - touch sensitive etc.

Has anyone any experience of this fault and any suggestions as to how it might be remedied. I need my piano!!