JD-XA parameters adjusting on their own

[BrandonD]

Bought a JD-XA, it has started giving me some issues, hopefully you guys can assist or advise.

Basically, when the synth is powered on, parameters will just start adjusting of their own accord - it is often the pitch parameter and it will just randomly move a few cents up and then a few cents down over and over, I can see it adjusting on its own in the digital screen. This seems to happen particularly when I have a mic plugged into the vocoder port in the back.

Thank you for your time and any help you can provide!