Brother International HE-800A Instruction Manual - English - Page 102

16. TROUBLESHOOTING Cause Thread tension Needle bar plate Lower thread clamp Check Zigzag thread upper thread tension Vertical and longitudinal needle bar play Lower thread retainer cam Remedy Adjust the upper thread tension appropriately. Reduce the needle bar play, or replace the parts. Lower thread retainer cam should be sitting firmly on lower thread clamp plate roller. Cam Roller Page 62 - - 3998Q Thread scraps and dust Clean around the lower thread presser. blocking area around lower thread clamp and - lower thread presser Lower thread clamping ࡮If the lower thread clamp and lower thread presser force are bent, replace them. ࡮Check that the screws are tightened. Screw - Lower thread clamp Needle plate Joint sewing 3999Q Relation between material ࡮When using knit material, replace with the -3 and needle plate needle plate. - ࡮Replace with a needle plate with a smaller needle hole. Angle of work clamp ࡮Replace with short work clamp that matches the means that material is not sewing length. being clamped. ࡮Use the accessory auxiliary sheet. 75 ࡮Process the work clamp assembly to match the joint section. (Attach or remove rubber.) １６-３. Uneven seams (1) ...... At the sewing start Cause Upper scissors thread Upper thread feeding Check Installation height Upper thread scissors opening timing Upper thread scissors operation Thread take-up amount Remedy Adjust the upper thread scissors installation height. Adjust to an appropriate opening timing. Apply grease to the inclined face of the opening cam. Loosen the screw to decrease thread take-up amount so that upper thread does not pull out of scissors assembly at the sewing start. Page 75 76 76 Screw Increase Decrease - HE-800A 4000Q 94