Originally Posted by Nanamoms

Hmm, I don't have that machine but I have 2 Brothers. If the top thread is breaking, sounds like a little piece of something is stuck in the thread guides. Take a piece of "UNWAXED" dental floss, tie knots in it about every 3 inches and starting at top, thread floss just as if you were threading actual thread. Run this thru the thread guides 2 or 3 times. Any little bitty piece of fuzz can cause your thread to break.

Another option is how the thread comes off the spool pin. Since you've used several brands, try putting your spool on a thread stand sitting behind your machine. Right behind where you start threading. Another hint is to NEVER pull your thread back up thru the guides, clip it at the spool and pull it down and out the needle.

Be sure bobbin area doesn't have any fuzzies/lint either. Believe it or not that will cause the upper thread to break.

You can buy the single thread stand very cheap at the fabric store. They usually have a wire guide that folds up and after putting your spool on the stand, thread thru the wire and then start threading your machine.

THEN, if all this fails, call your dealer or go to the Bernina site on line. I find lots of answers to my problems at my Brother on line site just from posting in the forum.