Originally Posted by
sandyfullmer
Try a new bobbin. The machine reads those little silver marks and if they are worn in places it causes the problem you are having. Found that out with my 820.
Agree ... if it wears out ... you need to replace the bobbins.
There is nothing wrong with your machine ... in fact, it is your machine (and the sensors) doing the job they are meant to do.
About the variegated thread comment .... I've run miles of it thru my 820, with no problems.
I don't think you could categorize a machine as not liking variegated threads ... whereas less success with a specific type/brand (variegated or plain) might be more realistic.