– 73 –
Troubles
Causes
Corrective measures
Page
10. Needle thread breaks
at the start of sewing,
or the wrong side of
seam is dirty.
1. Tension at the start of sewing is too low.
○
Increase tension at the start of sewing.
11. Knife drops even
when needle thread is
cut.
1. Check whether the thread breakage detector
plate is properly adjusted.
○
Adjust the detector plate.
(Refer to the Engineer's Manual.)
–
12. Needle breaks.
1. Check whether needle is bent.
2. Check whether needle comes in contact with
the blade point of hook.
3. Check whether needle thread trimmer comes
in contact with needle when it opens.
4. Check whether needle comes in the center of
the needle hole of throat plate.
5. Needle stop position is too low and needle
comes in contact with needle thread trimmer
when it closes.
○
Replace the needle.
○
Adjust the needle-to-hook timing.
○
Adjust the installing position of needle
thread trimmer.
○
Re-adjust the installing position of throat
plate base.
–
13. Knife drops plural
times.
1. Check whether the cloth cutting knife dropping
is set to plural dropping.
○
Release the plural time setting.
