My Zacc Puckman has this huge joystick and sometimes it stucks into one direction.
Removed the control panel and one screw from each leaf switch, in this way you can turn them around the second screw and reach the holes under them
In these holes, there are red plastic sticks, if you push the joy to a direction, these will close the leaf switches.
I don't know, if these plastic things are factory made, or a later replacement of some metal components.
The holes and the plastic sticks were covered by the mixture of dust and grease, I cleaned them and used some WD40 also, the joystick works fine by now.