Brother HE-800A - Manual (Page 100)

HE-800A
16. TROUBLESHOOTING
92
ውዒ. 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.
ውዒ-ው. Upper thread breakage
Cause Check Remedy Page
Needle facing As viewed from the direction of the face plate,
attach needle so that the notched part of needle
faces frontward.
57
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
Needle and thread Replace needle that fits the thread -
Upper thread threading Thread the upper thread correctly. 58 Threading
Lower thread threading Thread the lower thread correctly. 60
Flaw or abrasion on the
thread path Polish with buff or replace the part.
Especially, pay attention to finishing around needle
plate hole.
-
Flaw on the rotary hook
point and rotary hook
edge Polish with buff or replace the part.
-
Thread path
Flaw on the rotary hook
holder Polish with buff or replace the part.
-
Zigzag thread upper
thread tension Adjust the upper thread tension appropriately.
62
Thread tension
Bar tack thread upper
thread tension Adjust the upper thread tension while checking
stitches. (The stitches on top are the upper thread
and the stitches underneath are the bobbin thread.)
62
Thread take-up
spring Thread take-up spring
tension and stroke Loosen the thread take-up spring tension or shorten
the stroke to such a degree that does not cause
double hooking. Adjust it while checking bar tacking
stitches.
63
3996Q
3997Q
Needle plate hole
Adjust the rotary hook
overlap amount.
Check flaw here