Hello, I’m Ron and I am a Yamaha certified musical instrument technician. I understand you are having a problem with your CVP 206. You said you tried turning it off and on, did you try that after the unit had been off about an hour to cool down? It might be a heat related problem.
I wanted to check back with you to see if the problem was corrected. I am glad to help any way I can but without more information from you there is nothing I can do.