Sounds like you have done everything that is recommended to try first except checking for pieces of broken thread esp. around the tension disks and cleaning the bobbin area. If this does not solve your problem check if this same thread breaks when using a different design. It's possible there is a bad spot in the thread. Also try slowing down the speed of your machine while stitching.

Check the tension part. The bit that you go down then up. Sometimes a bit of thread can get caught and catch any new thread trying to get past.
Not a very clear explanation I know.
It will be something very simple. Also take the bobbin case out and give it a clean.

This may not be your problem, but when I get a thread that keeps breaking I try another and if that does not break the one that was breaking goes in the bin. I do admit a lot of my threads are 15 to 20 years old.

I keep unwaxed dental floss near my machine and run a piece through the machine just as if I were threading the machine with it to catch any bits of thread or lint that gets stuck where I can't see it or get to it. I do hope you find the problem quickly and get back to stitching.

Have you taken out the bobbin case and cleaned there? Karen's idea about the dental floss has helped me before.

Just wondering, what kind of machine do you have? I read a post recently where someone was having thread problems like me. I haven't tried this yet, because I have been able to 'work around' my problem,having to do a trick to 'baby' my machine, but heres what they said. It was a Brother7??, can't remember their numbers. (mine is aBrother750D) They said the top thread gets caught in some part after you thread correctly and causes the thread to tighten and break. They said (and I haven't done this yet) to take the screw out and this small cover off (I'll try to post a photo of mine). They said just by removing the cover, helps it not get caught, therefore it won't fray and break.Here is my machine (boy I need to wipe it off!-lol) and this is the screw they said to remove,and take the cover off. They also said the machine may not be as pretty without the cover, but if it eliminates the problem, it's worth the look. It shouldn't hurt to try it and I hope it works for you.-Toogie

Next try the dental floss and then if still breaking or snagging, then check to see if the throat plate has any burrs that are catching the thread. Good Luck!

Lots of good suggestions...also check the bobbin case to see if there are any rough spots around the edge..sometimes a needle strike can cause a burr on the bobbin case that will cause your thread to shred or break...If you find a burr or rough spot, take an emery board or nail file and gently rub over the burr and make it smooth...I have had to do this on a couple of occasions...

Looks like it gets tangled on the arm,

are you using a thread stand, I know when I quit using the thread holder on my machine a lot of thread breakage stopped.

Did you ever figure it out, Jean? I often have this problem, but mine is usually the needle needs changed, or some thread is caught in the way.

Just had a thought check the foot. I have a Janome and my embroidery foot is plastic and it developed a hair line crack in it and was catching the thread. Took the tech some time to find the problem as it look ok at a glance only could see the crack when it was removed.

For sure, let us know when you solve the mystery. Also, what Brother is yours?

Hi Ladies, Well I am sewing again, Took lots of fluff from the machine, checked springs etc, but I'm wondering if it was the design after all that, but on the bright side I have a lovely clean machine, Thanks to you all, Jean xx

Every body join in the happy dance.

Joining in on the Happy Dance...

So glad you got your machine working again Jean. It's so frustrating trying to find the cause to these problems. Doing a happy dance with you. Love Chris

Hope it is resolved!! Lots of ideas.

Thanks ladies, I couldn't have done it without all your help, Jean xx

Great news to hear you have your machine working again. Doing the Happy Dance for you. Hugs