First, check to make sure you have re-engaged the wheel after winding a bobbin.
AW
January 2009
If you have a buzzing noise coming from the motor then the chances are you have thread stuck in the bobbin case area, you need to take out the bobbin case and the raceway and check, you can only do this if you have a front loading or side loading bobbin case, any problems e-mail me below.
Ken