I had this problem with my 1500 too! A poster here told me how to fix it. The top bar that has the three holes are for tension of the different wts. of thread. For regular piecing thread only thread through the far right hole and thread down the hole not up and then back down. That solved the unthreaded needle problem for me! I went to two different dealers asking about this problem and each one said I needed a new thread cutter. I won't be buying anything from their shops.