Yamaha Clavinova CLP-480 - Right Panel Board

My CLP-480 started going immediately to “Strings 1” voice and won’t switch to anything else. I can hit the “Grand” button and it will add the Grand voice (sometimes) along with the strings but then it always goes off and just goes back to strings within a few seconds. I’ve tried resetting to factory. The first time, the piano worked ok for about 30 seconds then it went back to malfunctioning. The second time I reset the piano and thereafter, it didn’t make any difference.

After some disassembly, I’ve identified the right panel board (the one that houses the electronics under the voice buttons). I’m thinking that would be a start to replace that but I can’t find it sold anywhere.

Any ideas on whether I’m going down the right path and if so where to source this part?


@wernersaurus I notice you posted on other Yamaha comments - is this something you could weigh in on for me?


had a look on the schematics - the right panel board (PNR) has got no “intelligence” on it - just switches and LED’s (right side of extract below - left part is LCD stuff) - your problem described above cannot be caused by any of them - disconnect CN71 and CN81 connectors on the board (the switch/led bus lines) and proof the point. Also - measure all the diodes in series with all the switches … a shorted diode can cause is to be re-read on every scan. but that would only go back to the same setting …

Thanks , I’ll check that. Just an fyi - when I unplug CN302 and CN202 connectors and then power on, it defaults to the grand piano (obviously with the board disconnected nothing lights up and nothing can be selected ). Which is actually a halfway workable long term solution since I don’t use the other voices that much.

which would suggest a shorted diode - maybe even two ?!