My CG 500/550 Singer Sewing Machine's bobbin isn't working?

If the thread is not being pick-up by the needle bar check to make sure you have the needle in correctly. (The flat side of needle should be facing the back). If changing the needle position does not correct the problem then you will have to take the machine apart to determine what has happened. It could be as simple as timing the lower rotating hook. Or it could be needle bar timing.. Unless you have some degree of understanding how a sewing machine works you may create more problems by taking it apart and should seek an experienced sewing machine engineer to perform the repair.

Rupert
April 2020