A lift cable usually comes off the drum when slack develops.
- The door was opened with a broken or weak spring.
- The door hit an obstruction or froze to the floor.
- Cables lost tension due to incorrect winding or a loose set screw.
Once slack occurs, the cable can unwind unevenly and jump grooves. The fix is to safely remove all spring tension, re-seat the cables in the drum grooves, and rewind to the correct number of turns for your door height.