My Euro-Pro locked up and before I took it to a repair shop (the closest one was 2 hours away) and paid $150 for they estimate of the problem, I decided to take one more look at it. I took the right side off and the belt was fine. I took the left off, the needle assembly was fine. Then I took the bobbin assembly completely apart and found a black thread wrapped around 2 screws.I took a pair of tweezors and got the thread.Then I put everything back together and turned it on and it worked just fine. But mine is not a computerized model. If yours is,I wouldn't try a self-fix .