Bernina 830LE Manual - Page 166

Avoiding and Solving Problems 166 Fault Uneven stitch formation Skipped stitches Upper thread Breaks Lower thread breaks Some failures may be remedied by switching the sewing-/embroidery computer off, then on again after 10 seconds. Cause Lower thread incorrectly threaded Upper thread incorrectly threaded Poor quality needle or bent Upper thread too tight/too slack Poor quality thread Lower thread too tight/too slack Incorrect needle system Needle bent or blunt Needle/thread combination is incorrect Needle inserted incorrectly Incorrect needle point Poor quality needle Upper thread tension too tight Incorrectly threaded Poor quality or old thread Stitch plate or hook tip damaged Troubleshooting Repair Check lower threading path Check upper threading path Use a new, good quality needle (BERNINA) Reduce/increase upper thread tension Use quality threads (Isacord, Mettler, Gütermann) Reduce/increase lower thread tension Use needle system 130/705 H Use new, good quality needles (BERNINA) Match the needle to the thread size, see page 24 Insert needle as far up as it will go Match the needle type to the fabric Use good quality needles Reduce upper thread tension Check upper thread threading path Use good quality thread Have the sewing-/embroidery computer checked by a dealer Remove any remaining threads in the pre-tension with tweezers and check the take up lever, see page 168 Lower thread tension too tight Stitch hole in the stitch plate has been damaged Needle blunt or bent Reduce lower thread tension Have the sewing-/embroidery computer checked by a dealer Use a new needle