Hello Jade,
Do you mean the raceway is not moving because the bobbin case should not move, if the raceway is not moving that is the part that the bobbin case fits in then either the screws have come loose on the raceway or something serious has broken, if you can see the raceway moving then the machine will need retiming and I can give you instructions for that if you e-mail me.
Ken
drivewithken@blueyonder.co.uk, May 2008