My husband bought a 403 at an auction for $5.00 in a not so nice cabinet. Had no cords. Purchased the cords, runs great, only thing it has a zig zag cam but only does straight stitch. Is there a secret to get this to work for zig zag. It had no attachments, book. Was very dirty, cleaned it up. I know nothing about how the cams are supposed to work. Any info is greatly appreciated.