In my experience, this has often been due to dirt or some liquid. Do Not use contact cleaner near any of the rubber parts! However do gently wash the circuit boards and examine the connections. Once on a Casio, I knew coffee got into the volume knob area, and it stopped working. ON a hunch, Casio sent me a replacement part (well, a little group of parts), and it fixed the problem. I had to replace the little PCB that housed the volume stuff. It was a $600 keyboard so it was worth it. Look for sticky ness or water damage and then contact Casio!
Excellent guide ! Thank you!!! This old back cover was a tad brittle, but nothing that can be fixed.
Lorsqu'il en aura reçu, il pourra afficher un graphique de sa réputation au fil du temps.
Voici un aperçu de ce à quoi ressemble ce graphique :
Aucun point de réputation obtenu pour l'instant.