If you took the needle plate off. When you put it back on with the screws, LOOK AT THE BOBBIN HOLDER BASE. IT HAS TO HAVE THE CURVED NUB PART INSERTED between the plates that are hooked on the bottom of the needle plate. I know I'm not speaking right, but I hope you can understand what I'm trying to say. I have fiddled with mine all day and finally got it to sewing.