You might turning the turn table around manually 50 to 100 or more rotations to see if it will unwind the winding mechanism/spring. It is sort of like shaking a pocket watch or wind-up wristwatch to keep it running to unwind on over wound spring. If you can attach a piece of rubber to the face of the chuck on a drill, you could probably hold it against the spindle, then start the drill to unwind the mechanism.