Korg Poly800/EX800 Users

I had a look at it on the inside but don't know much about it.
The joystick only seems to work when held downwards. If i move it up or left to right there is no effect.
I didn't notice any file in this group about the subject. not sure that i want to remove the pots on the joystick/the slide pot to test them but i guess i will if i have to.
...advice? anyone... buler...
d