Brother International BAS-612 Instruction Manual - English - Page 57

TROUBLE-SHOOTING Phenomenon Cause Bent needle, blunt tip Needle thread breaks H Incorrect needle fitting Incorrect threading Excessive needle thread tension Incorrect clearance between rotary hook and bobbin case opener H Incorrect needle and rotary hook timing Incorrect threading Bobbin thread breaks Excessive bobbin thread tension Oil waste threads on bobb,r case surface Uneven stitches Bent needle. blunt t Bent needle, blunt tip Incorrect needle fitting Skipped stitches Incorrect threading Stitches do not tighten Incorrect timing of needle and rotary hook Trimmings collected around rotary hook H Weak thread take-up spring or its limited working range Insufficient needle thread tension _ .1 Insufficient bobbin thread tension Incorrect needle fitting Needle breaks Needle doesn't stop at up position. Bent needle, blunt tip Incorrect needle and rotary hook timing Needle up stop element fault Where to check Needle Needle facing Threading Needle thread tension Threading Bobbin thread tension adjustment screw tightening Needle Needle Needle facing, height Needle thread threading Thread take-up spring power, action Needle thread tension Bobbin thread tension Needle facing, height Needle Needle up stop element position -53- Solution Replace needle Page 35 Re-fit needle correctly 35 See "Threading the 11 needle thread" See "Stitch tension" 27 See "Needle and rotary hook timings 35 adjustment" See "Needle and rotary hook timing 35 adjustment" See "Threading the 11 needle threads" Correctly tighten 27 screw Clean away all waste threads and oil Replace needle 35 Replace needle 35 See "Fitting the needle" See "Threading the needle threads" See "Needle and rotary hook timing adjustment" Clean around rotary hook 35 11 35 z See "Stitch tension" 27 See "Stitch tension" 27 See "Stitch tension" 27 See "Fitting the 35 needle" Replace needle 35 See "Needle and rotary hook timing adjustment" See "Position detector adjustment" 35 z