Bobbin don't turn

In the shuttle area there is a silver round piece- called the shuttle race cover. It has a black ear on the right and a black ear on the left. Push the right ear to the right, and the left ear to the left and the silver ring should come out. Behind the silver ring is the bobbin case stuck in the hook. Remove that, jiggle it, move it, just work the bobbin case out of the hook. Now put the hook back in the machine. In the machine there is a driver that looks like a half moon. Your hook looks like a half moon- make a full circle out of both of them. Re-install the race cover, pushing the left ear to the right and the right ear to the left to secure the race cover, and your problem should be solved.