JUKI
MH-380, Instruction Manual

Page: 56 / 60

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Troubles Causes Corrective measures
4. Needle breakage 1 Needle is bent. ™ Replace it with a straight needle.
Refer to “11. ATTACHING THE NEEDLE”.
2
The timing of the needle motion with
that of needle is not correct.
™ Adjust the timing.
Refer to “14. ADJUSTING THE FEED TIM-
ING”.
3
Position of the presser foot is wrong. ™ Align the needle holes on the throat plate and
the presser foot with the center line of the
needle.
4 Motion of the needle guard is not ad-
equate.
™ Check the position and timing of the motion of
the needle guard.
Refer to “18. MATCHING THE MOTION OF
THE NEEDLE GUARDS WITH THE LOOP
GUIDE”.
5 The tension of needle thread is too
high.
™ Loosen the tension.
Refer to “8. THREAD TENSION”.
6
Thickness of the needle is not suitable. ™ Replace it with a suitable needle in accordance
with the quality and weight of the sewing ma-
terial.
Refer to “11. ATTACHING THE NEEDLE”.
5. Puckering
1
Thread tension is too high. ™ Reduce the thread tension, especially the
looper thread.
Refer to “8. THREAD TENSION”.
2
Timing of the looper thread take-up is
wrong.
™ Adjust it, if necessary.
Refer to “19. POSITIONING THE LOOPER
THREAD TAKE-UP”.
3
Thread paths are not smooth. ™ Make them smooth.
4
Pressing force of the presser foot is too
much.
™ Adjust it by loosening the presser spring regu-
lator.
Refer to “9. ADJUSTING THE PRESSER
FOOT”.
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