Quote from matijapkc :

O.K. I'll try to do something with my father... He'll know that stuff... I'll let you guys know.
But, what I was asking was this: I have 180° potentiometer (90 left, 90 right). Could I put potentiometer with 500°?

I guess you need then to put lower nominal potentiometer. Or higher. Don`t know exactly , your father will know this

O.K. I'll try something this weekend. I have no time now. The school and all stuff.....

We gave it a shot... But...
We done nothing. Cleaned the potentiometer, but nothing happened.
We can't replace it because, we can't reach it, and an guy from some tech shop was reparing similiar model (both are Genius) and he couldn't find anything that could say the model of potentiometer... So, it is now useless.

Can you give more precise link? On those few pages isn't anything about it...

try looking for an online manual. there might be specs of the pots in there. or you could buy a few different pots and then it's a matter of trial and error.