I have a Clavinova CVP96. Lately a D note stopped working for a few minutes. Later a G sharp in the same octave behaved the same. The next day a D note in a different octave and then another G sharp. Every day another D and another G sharp behaved the same. They worked for a few minutes and then stopped working, and later came back to life. Now, it's all the D and G sharps in the upper half of the piano. This is true in all the voices. I tried resetting the piano by holding the right most white key and turning on the piano, but it didn't help. Please help. I'm very sad about this. I can't afford to purchase another piano.