Hello,
I would like to know if there is a maintenance manual for the ST 16S radio control - because my joysticks no longer work and John Mitchel that they can get scratched
Another thing I need to add is have you performed the controller calibration with the sticks acting this way. If you have that only compounds the problem.
A more complete description of what the problem is would also help us steer you in the right direction.
Your best bet IMHO would be to buy new sticks from Yuneec Skins and have them replaced after doing what DoomMeister suggests, there is also a good You Tube Video on how to remove the rear ST16 panel.