
69
Short upper
thread after
trimming due to
separation failure
Thread break
before trimming
①
Movable blade is too fast or
too slow to separate the
upper thread
②
Incorrect position of picker
③
Picker failure
①
Upper thread is too short
•
check main and sub
tension adjuster
•
dent or damage of
movable blade
②
Lower thread is too short
•
doesn
’
t unwind smoothly
•
too weak or too elastic
■
Adjust insert angle of
movable blade (295
°
)
■
Adjust picker position
■
Check and change X, Y
drivers
■
Adjust upper thread tension
■
remove dent using
whetstone or sandpaper or
change movable blade
■
adjust or change bobbin
case spring
■
change lower thread
■
Check fuse spec.
■
Too short lower
thread cannot make
stitches right after
trimming
Inspection & Repair
Cause
Error Type
Reference
Check for dent
Summary of Contents for MA-6
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