Will it take any stitches at all, or will it stitch some, and then stop? I have a 440, and there's a "pattern repeat" button that is very easy to press instead of reverse, at which point, it will sew 3 stitches and then STOP. Also, check your actual stitch, and make sure you've got a plain straight stitch. Finally, make sure that you haven't adjusted your presser foot pressure all the way off. I did that to work with the BSR and forgot to take it off and was very confused for about 10 minutes.