Brother HE-800A ￿￿. TROUBLESHOOTING, CAUTION, ￿￿-￿.Upper thread breakage

￿ 16. TROUBLESHOOTING

￿

￿￿. TROUBLESHOOTING

CAUTION

Turn off the power switch and disconnect the power cord before carrying out troubleshooting, otherwise the machine may operate if the treadle is depressed by mistake, which could result in injury.

￿￿-￿. Upper thread breakage

Cause				Check		Remedy	Page
Needle		Needle facing				As viewed from the direction of the face plate,	57
						attach needle so that the notched part of needle
						faces frontward.
		Needle installation height				Insert the end of the needle shank so that it touches	-
						the top edge of the needle hole of the needle bar.
		Bent needle				Replace needle	-
		Blunt needle tip or burr				Replace needle	-
		Needle and thread				Replace needle that fits the thread	-
Threading		Upper thread threading				Thread the upper thread correctly.	58
		Lower thread threading				Thread the lower thread correctly.	60
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.
							-
						Needle plate hole
						3996Q
		Flaw on the rotary hook				Polish with buff or replace the part.	-
		point	and rotary		hook
		edge
		Flaw on the rotary hook				Polish with buff or replace the part.
		holder				Check flaw here
						Adjust the rotary hook	-
						overlap amount.
						3997Q
Thread tension		Zigzag		thread	upper	Adjust the upper thread tension appropriately.	62
		thread tension
		Bar	tack	thread	upper	Adjust the upper thread tension while checking
		thread tension				stitches. (The stitches on top are the upper thread	62
						and the stitches underneath are the bobbin thread.)
Thread	take-up	Thread take-up spring				Loosen the thread take-up spring tension or shorten
spring		tension and stroke				the stroke to such a degree that does not cause	63
						double hooking. Adjust it while checking bar tacking
						stitches.

HE-800A 92