http://wheelchairelectronicsrepair.c...hair-joystick/
These guys say on their web site, "if you don't see a picture of your joystick, we may be able to fix yours".
Ck with them and let us know what they say.
If you have a GOOD QUALITY ohm meter and some experience with electronics, you may test the lead. If so, and it's bad, you will need GOOD QUALITY solder remover and solder iron. Lack of experience soldering electronics usually results in a non fixable part if you attempt to FIY. Requires surgeons stability in hands. "You know you are a good mechanic (or other trade), when you know when not to do some things"