I have a Brother embroidery machine and yesterday in middle of an embroidery project, the thread kept breaking. It finally got so bad that the tension discs hidden inside the were jammed with thread bits, (I didn't find this out till a trip to the repairman where I purchased it) Apparently,with the auto guided threading, sometimes the thread doesn't go where it is supposed to go,(you cant see this happen) only to snap off later. Then you have no tension on the top thread and it results is a real jam under the presser foot. Guess what the repairman told me, I am not the only one, this is a design flaw in some of the Brother machines, no solution either.