Help-- My Bernina 830 is constantly having bobbin (upper tread breakage) problems with regard to the embroidery section. I have had it at the shop more than home use. Any tips would be appreciated as I have gone through all the recommendations, i.e., correct thread type, check bobbin threading is done right; slow speed; oil, check for loose threads. I am working on an embroidered and pieced quilt for our grandbaby.. Need help soonest. many thanks.
