Took the plane out this morning for a short flight. Noticed an unusual noise as the bi-fold door opened...took plane out, and when closing the door it jammed. Found one of two cables had jumped off its pulley. After a bit a trying to move the door the other cable also jumped off its pulley. Fortunately two friends were nearby and together we finally got the plane back in the hangar and after even more work got the door down (more of less free-fall into place.) I will get new cables because they were kinked in the process, but cannot reach the pulleys because they are behind a large I-beam, so I will cut two small windows in the door at the pulley location and re-string new cables, then put window plastic over the cut outs. Lots of work, but it should be OK. Its a Schweiss door that has been trouble free for a bit over 20-years. But for now the plane is stuck in the hangar...at least its out of the weather until I can get things fixed.