Brother HE-800A ￿￿-￿.Uneven seams (5)……Poor rounding of seam, ￿￿-￿.Uneven seams (6) …… Around rear tack or front tack, Seam lifts up and does not tighten at the sewing start

￿							16. TROUBLESHOOTING
￿
￿￿-￿. Uneven seams (3) ……Seam lifts up at the sewing start
Seam lifts up and does not tighten at the sewing start
Cause			Check		Remedy			Page
Upper	thread	Upper	thread	scissors	Adjust the timing so that the upper thread scissors
scissors		gradual opening timing			gradually start opening when the feed mechanism			76
					moves about 1.5 - 2.5 mm.
		Upper	thread	scissors	Apply grease to the inclined face of the opening			76
		operation			cam.
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

￿￿-￿. Uneven seams (4) …… Uneven sewing pitch at the sewing start

Bird’s nests form at the sewing start, and after 5 – 6 mm the sewing pitch suddenly increases

Cause	Check		Remedy	Page
Lower thread clamp	Lower thread	clamp	Advance the timing at which the lower thread clamp	77
	opening timing		starts to open.

￿￿-￿. Uneven seams (5)……Poor rounding of seam

Cause		Check		Remedy	Page
Thread tension	Zigzag	thread	upper	Adjust the upper thread tension appropriately.	62
	thread tension
	Zigzag	tension	disc	￿Check the opening of the zigzag tension discs.	62
	opening			￿Replace the tension release solenoid.
	Lower thread tension			Adjust the lower thread tension appropriately.	61
Threading	Upper thread threading			Thread the upper thread correctly.	58
	Lower thread threading			Thread the lower thread correctly.	60
Stitch patterns	Purl stitch, whip stitch			Set using parameter number 11.	37
Tension release	Tension release timing			Use parameter numbers 63 to 66 to change the	44
				tension release on and off timing.

￿￿-￿. Uneven seams (6) …… Around rear tack or front tack

Cause			Check		Remedy	Page
Tension release		Tension release timing			Use parameter numbers 63 to 66 to change the	44
					tension release on and off timing.
Threading		Upper thread threading			Thread the upper thread correctly.	58
		Lower thread threading			Thread the lower thread correctly.	60
Zigzag	thread	Zigzag	tension	disc	￿Adjust the tension disc opening amount.
tension		opening			￿Check the opening of the zigzag tension discs.	62
					￿Replace the tension release solenoid.
Upper	thread	Upper	thread scissors		Apply grease to the inclined face of the opening	76
scissors		operation			cam.

HE-800A 96