I just picked up a "Star Wars Trilogy Arcade Stand-Up Edition" I've never really worked on this type of game before and was hoping someone on here could help. I've managed to get the joystick calibrated for the most part but weather the joystick is being moved or not it always seems to jitter around it's never still and is not smooth moving at all making it tough to aim. What would be causing this is there some adjustment I need to make or part I need to look into replacing?