I had a motor drive MX that sometimes slipped on ONE of my MXen. I never figured out why--I just put the drive on the other MX. Clearly the camera was the issue.
When my Super Programs got motor-drive-death, the symptom was that they would stop winding towards the end of the roll and the light would come on, just as the MX winder described. The problem was diagnosed as damage to the film-advance gearing of the Super Programs which caused them to bind or something, causing extra tension in the film advance and making the drive think it had hit the end of the roll and stop. New gears fixed it, while I could get new gears. I'd suggest you try the winder on a different MX. If it works, something in the mechanical train driven by the winder is putting up too much resistance due to dirt, damage, etc. DJE
