Yamaha CVP-103 control buttons don't work anymore

by Bart
(Antwerp)

Hello

My yamaha piano cvp-103 still makes sound. But suddenly all my control buttons and midi don't work anymore. Display still works, piano still works, sound still works, but all the controlbuttons and midi don't work anymore. Normally they light up when I start the piano but even that doesn't work.
I tried to look for broken soldering and removed dust, but everything seems intact.
I tried resetting by start up with most right white button, but that didn't help.

Can someone help me please. I miss my piano, while it is standing next to me.