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WARNING :
Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine.
Trouble Cause Checking Corrective measures
1. One or several
stitches skip at the
start of sewing.
1-1) Thread remaining at the needle top
after thread trimming is short.
1-A) Check the routing of needle thread. Thread the needle thread correctly.
Adjust so that abnormal needle thread tension is not
applied.
1-B) Thread tension given by the tension con-
troller No.1 is too high.
Decrease the tension given by the tension controller
No.1.
1-C) Check the rising amount of the thread
tension disk No.2 at the time of thread
trimming.
Adjust so that the disk is raised by means of the
thread release solenoid.
1-D) Thread trimmer timing is excessively
advanced.
Refer to “2.-(16)-4) Thread trimmer cam timing”.
1-E) There are scratches on the moving knife
and the hook.
Polish with buff or replace the part with a new one.
1-F) Presser foot drops from cloth at the time
of thread trimming.
Perform thread trimming on cloth.
1-2) Bobbin thread is not clamped. 2-A) Position of the clamp spring. Refer to “2.-(16)-1) Position of the counter knife and
the clamp spring”.
2-B) Pressure of the clamp spring is too low. Refer to “2.-(16)-1) Position of the counter knife and
the clamp spring”.
2-C) There are scratches on the clamp spring. Replace the clamp spring with a new one.
2-D) Needle thread removes bobbin thread. Increase or decrease the tension of the tension con-
troller No.1.
1-3) Needle is too thick. Replace the needle with a thinner one.
1-4) Needle hole in the feed dog is too large. Replace the feed dog with small needle hole.
1-5) Pressure of the presser foot is too low. Increase the pressure of the presser foot.
1-6) Stitches are too small. Do not pass thread through the thread presser sec-
tion of the thread guide on the needle bar.
(2) With regard to thread trimming
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