I haven't had any problems with mine that I haven't been able to figure out. The problem I had with the tension area is that the little spring hook thing that's on the outside of the tension knob allowed the thread occasionally to get wrapped around the spring, tension disks twice, or around the take up arm. I just put a piece of tape over it and it fixed the problem. When the thread breaks, check to make sure everything is still threaded correctly and the thread didn't jump. Also, when I first got my machine, i kept wanting to put the thread thru the eyelet guide then the tension disk. The thread goes from the spool, thru the tripple guide then directly to the tension disk.