I have a singer model #648. It has the push button winder. It will not fill the bobbin. The needle position is in C, the stitch width selector is at 1. The buttonhole Is off My bobbin push button is pushed to the left. I have followed the instructions, but it will not fill the bobbin. The needle goes up and down, but no thread in the bobbin. How can I fix it?

Jeri, February 2018