Brother International HE-800B Instruction Manual - English - Page 93

11. TROUBLESHOOTING 11-12. Uneven seams (10) ...... All stitches Items with a "*" in the "Page" column should only be handled by a qualified technician. Cause Check Remedy Threading Upper thread threading Thread the upper thread correctly. Lower thread threading Thread the lower thread correctly. Thread path Flaw or abrasion on the Polish with buff or replace the part. thread path Especially, pay attention to finishing around needle plate hole. Page 22 25 * Needle Thread chips or dust Upper thread Rotary hook holder Needle plate hole 3996Q Needle installation Needle size Rotary hook rim Rotary hook edge Around needle plate hole Upper thread tension Thread and needle Flaw on the rotary hook holder Insert needle fully into needle bar. Replace needle with thicker one. Remove thread chips or dust. Increase upper thread tension while checking stitches. Replace needle with one that fits for the thread. Polish with buff or replace the part. Check flaw here Adjust the rotary hook overlap amount. 21 * 62, 63 26, 27 - * 3997Q Rotary hook holder and Adjust the rotary hook holder and inner rotary hook inner rotary hook overlap overlap amount. 66* amount Rotary hook Rotary hook lubrication Decrease the quantity of lubrication oil. * Note that if you reduce the amount of oil too much, 16* thread breakages may occur. Bobbin winder tension Bobbin thread tension bracket Use the tension nut to adjust the lower thread winding tension. 24 Uneven bobbin winding Move bobbin winder tension bracket up and down to adjust. 24 Lower thread Lower thread tension Adjust the lower thread tension. 26 Bobbin case Damaged outside of Polish with buff or replace the part. bobbin case and bent * Use the HE-800B bobbin case. * bobbin holder spring, etc. Stitch patterns Purl stitch, whip stitch Set using parameter number 53. 40 HE-800B 84