it could be electronic, but sometimes electric motors/gearing/grease get gummed up from non-use.
Is there a way you can gently turn the shaft of the winder? Without marring/damaging it?
Oddly, years ago my grandmother's electric can opener died, and she had another in the basement, New, and never taken out of the box. The "new" one was at least 15 years old. We had to manually exercise it a bit, but it freed up and started working without issue. I had a similar thing happen on the mechanical shutter of my grandfather's wind-up 8mm movie camera.
If it takes a lot of force to get it moving, you may want to open and clean the unit. Otherwise, it's possible that it's just a "little bit" stuck.