My Yamaha Motif XF8 changes tones itself

I noticed my Yamaha Motif XF8 changes tone by itself. Sometimes it takes itself to a particular page, sometimes utility or if am on performance it goes to voice. Please what could be wrong, and what can I do to fix this up. Thanks.
Regards

Possibly a faulty tact switch or glitch in the rotary encoder used by the dial.

So how will i b able to detect or identify this faulty tact switch?
Also if it’s rotary encoder how do I fix this?

Thanks am most grateful

Well, find the button that is sending the phantom actions and then remove and replace it. I fixed a haywire Korg DSS1 by doing this once.

I tend to just replace the lot as they always go bad.

For the encoder, it depends on the type. Some are mechanical, some are optical. You either clean or replace. If you’re lucky the one installed can be opened by bending the 4 retaining lugs, then you can clean it. But they can have some sort of grease inside to prolong their life, never worked out what that grease is as it must not prevent electrical conductivity.

I think it is more likely the encoder, which is available here:

If the buttons are all still nice and ‘clicky’, they are probably not the culprit. Usually as a tact switch fails, it takes more pressure or multiple presses to get it to respond - that’s kind of the opposite of the issue you are having.

Thank you so much for this.

Hello chiemaft, pls were you able to fix this problem and how did you?
Thanks.

My sincere apology for late reply. I replace the rotary dial on the Pnc motherboard (Right side panel) of the Motif keyboard. Or you completely change the Pnc motherboard to a new one.

You can get this parts from Syntaur.