Hello people, all right?

Already I apologize if I'm creating a topic that already exists but I need a help how much an URGENT!

I recently bought a used XT LIVE (yes used) it usually works ...

But sometimes it gives a defect NEVER seen anyone complain ...

PROBLEM: Suddenly I'm playing, and she starts to get crazy ... I see on the display, which is moving potentiometers DRIVE 'crazy'. And when you position the volume pedal down (meaning, increase volume), I see the display that several other potentiometers are moving with the volume pedal - for all sides and for different values ​​... In returning to the volume pedal for low volume, I see in the display that the DRIVE potentiometer continues to shake ...

Does anyone know tell me why this is? I thought about factory reset, but I believe that is not a matter of software ...

I ask the help of you guys, because not even paid the pedal and suddenly get more expensive repairs than I think, I give back to the seller as soon as possible!

SOMEONE? I thank everyone who help me ...

I'm from Brazil! Sorry for my English ... xD