JUKI LS-1340, Manual

Page: 52 / 60

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52
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Troubles Causes Checking Corrective measures
Needle thread is not
caught.
Bobbin thread is not
caught.
Both needle and bobbin
t h r e a d c a n n o t b e
trimmed.
Tension of the bobbin
thread is too high.
Knife pressure of the fixed
knife is too high.
Initial position of the moving
knife is placed excessively
in the front.
Thread is not cut sharply.
Stitch skipping at the last
stitch.
Check the thread trimmer
cam timing.
Top end of the moving knife
has broken or been
scratched.
Stroke of the moving knife
is small.
Check the routing of bobbin
thread.
Top end of the moving knife
has broken or been
scratched.
Check the height of moving
knife.
The blades of moving knife
and fixed knife have been
improperly adjusted.
Pressure of the fixed knife
is too low.
Moving knife fails to work.
Adjust the tension of bobbin
thread.
Refer to “2) Adjusting the knife
pressure ”.
Refer to “5) Thread trimmer cam
timing”.
Refer to Causes “Thread cannot
be trimmed” and “Thread remains
uncut after trimming”.
Refer to “(5) Needle-to-hook
timing”
Refer to “5) Thread trimmer cam
timing”.
Replace the moving knife with a
new one.
Adjust the initial position of
moving knife.
Correctly thread bobbin thread.
Replace the moving knife with a
new one.
Adjust the height of moving knife.
Refer to “2) Adjusting the knife
pressure ”.
Refer to “2) Adjusting the knife
pressure ”.
Adjust the synchronizer timing.
Replace the thread trimmer
solenoid.
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