Yamaha Clavinova CVP-96 randomly no/higher sound on some key

Hello, I try to fix this old Yamaha keyboard CVP-96:

  • The problem is when I press the D0 key , sometimes I got sound, sometimes nothing , sometimes higher sound than usual…

  • Same for the key C2#

  • Demo sound is ok

  • I Replaced most of the capacitor of the mainboard and power board, the rubber of the keyboard, the 4Mhz resonator of the keyboard board, no changes…

  • I place a order on this site for the YMZ-702 IC, but still waiting for the parts.

Am I Right or it can be another IC?

Thank you.

Hi,

problem is mechanical more than electrical.
You have to remove the keyboard assy, and remove the two circuit boards - inspect them.
However - past experience points more towards the rubber strip between the key(s) and the circuit boards (see example pic below)

its part number is VY693500 and there is some for sale here:

Hi Wernersaurus, Thank you for reply,
I replace it first with a pink one, got a lot of nonworking key’s, then I replace with a new green one, and got the same problems has before…, problem is not the rubber…

Is the separator strip installed (the white strip in the picture above)?

Also - to install the rubber strip successfully you need to “relax” the keys. Installing the strip with the keys underneath makes the weight hammers pushing on the strip whilst installing it and in due course causes installation problems that lead to all sorts of issues.
To “relax” the hammer weights thread a thin 8mm wooden stick along the weights with the keyboard in normal position - the turn it upside down. The stick will stop the keys to engage whilst changing/intsalling the strip and separator.

Dear Werner, thank you very much for your help but I have already done everything you say, many times, and unfortunately, no changes…

Strangest think is that after 10 or 20 minutes, everything seem to work normally or at least better… That’s why I though changing the 4 MHz resonator… For me the last thing I can change is the YMZ IC

Hi Werner, I finally found the problem, the AEXL88L PCB contact are too used and I need tu puch the PCB at the maximum opposite position . Thank you for your help.

As long as you have it apart, you might as well re-felt, too. CLP, CVP have great action, but get “clunky” when the felt wears.

Did you clean the contacts and separator strip ? I was actually having problems with my CLP as carbon traces were making contact across the separator strip.