Brother HE-800A - Manual (Page 108)

HE-800A
16. TROUBLESHOOTING
100
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.
-
Needle bar height and
needle bar lift amount Adjust the needle and hook timing.
1. Adjust the needle bar height to “1” on the gauge.
2. Adjust the needle bar lift amount to “2” on the
gauge.
72, 73
Rotary hook
Thread chips on rotary
hook edge Remove thread chips.
-
Machine stopping
position Upper shaft pulley
stopping position Adjust the needle up sensor position.
77
Lower thread retaining
amount Adjust the lower thread retaining amount.
-
Lower thread snapping ࡮Use memory switch No. 02 to retard the work
clamp lifting speed.
࡮Process the lower thread retainer, lower thread
clamp and lower thread presser plate so that they
do not snap the lower thread.
79
Lower thread
Lower thread clamp
opening timing Adjust so that the lower thread clamp plate opens
when the feed mechanism moves 6 – 7 mm.
77
Slow speed Use parameter number 60 to reduce the slow
speed.
44
Sewing start speed
Slow start stitches Use parameter number 59 to increase the number
of slow start stitches.
44
Bar tack thread
tension Bar tack thread tension is
too strong. Make the bar tack tension as weak as possible.
62
Upper thread
breakage Upper thread breaks. Refer to “16-1. Upper thread breakage”.
92, 93
4000Q
Screw
Increase
Decrease
4003Q