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TROUBLESHOOTING GUIDE
Problem
Cause
Check
Solution
Page
Needle thread
escapes at start
of sewing.
Tension disc does not
open sufficiently.
Tension disc
opening
Adjust tension release.
Excessive pretension
―
Adjust pretension.
15
Needle too heavy for
thread
―
Use smaller size
needle.
Up needle stop position
too high, thread removed
by thread take-up.
Thread take-up
height at up needle
stop position
Delay up needle stop
position timing.
Thread cutter
mechanism does
not function.
Thread cutter solenoid
dose not function.
Check with tester
Replace thread cutter
solenoid.
Thread cutter signal not
transmitted.
―
Check circuits; refer
to motor adjustment
manual
Thread wiper does
not function.
Needle thread remainder
too long.
―
Adjust pretension
15
Excessive material,
presser foot resistance
―
Replace with presser
foot having back
channel.
Timing too early; wipes
thread before tension
disc closes.
―
Adjust timing.
Thread wiper operation
too short
―
Adjust operation time.
Summary of Contents for LS2-H540
Page 2: ...1...
Page 4: ...5 off A S 43 2 40 25 OFF A S A S 3...
Page 31: ...30 13 13 18 18 18 14 13 13 15 16 16 12...
Page 33: ...32 13 13 1 13 14 18 18 18 15 16...
Page 35: ...34 15 16 15 16 puff 18 13 26 28 26...
Page 37: ...36 15 1 15...
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