Brother HE-800A manual 108

￿16. TROUBLESHOOTING

￿

Cause			Check			Remedy			Page
Upper thread feeding		Thread take-up amount				Loosen the screw to decrease thread take-up
						amount so that upper thread does not pull out of
						scissors assembly at the sewing start.
								Screw
						Decrease	Increase		-
								4000Q
Rotary hook		Needle	bar height and			Adjust the needle and hook timing.
		needle bar lift amount				1. Adjust the needle bar height to “1” on the gauge.			72, 73
						2. Adjust the needle bar lift amount to “2” on the
						gauge.
		Thread	chips	on	rotary	Remove thread chips.			-
		hook edge
Machine	stopping	Upper	shaft		pulley	Adjust the needle up sensor position.			77
position		stopping position
Lower thread		Lower	thread	retaining		Adjust the lower thread retaining amount.
		amount
									-
								4003Q
		Lower thread snapping				￿Use memory switch No. 02 to retard the work
						clamp lifting speed.			79
						￿Process the lower thread retainer, lower thread
						clamp and lower thread presser plate so that they
						do not snap the lower thread.
		Lower	thread		clamp	Adjust so that the lower thread clamp plate opens			77
		opening timing				when the feed mechanism moves 6 – 7 mm.
Sewing start speed		Slow speed				Use parameter number 60 to reduce the slow			44
						speed.
		Slow start stitches				Use parameter number 59 to increase the number			44
						of slow start stitches.
Bar tack	thread	Bar tack thread tension is				Make the bar tack tension as weak as possible.			62
tension		too strong.
Upper	thread	Upper thread breaks.				Refer to “16-1. Upper thread breakage”.			92, 93
breakage

HE-800A 100