JUKI MB-372 Instruction Book

24. CAUSES OF MALFUNCTIONS AND REPAIRING
Nature of malfunctions
Reasons
Repairing
Thread breakage
Loop positioning motion
bad
Nipper is holding the
thread
Needle does not fall in
the center of hole
Quicken the right and left
timing of the loop positioner
Adjust with nipper bar block
Adjust with button clamping
lever jaw holder
Thread tightening
inadequate
Inadequate loop position
ing
Timing of tension disc
No. 2 bad
Tension of tension disc
No. 2 bad
Needle does not fall in
the center of hole
Button clamp pressure
bad
Adjust right and left timing
of the loop positioner
Retard the float timing of
tension disc no. 2
Adjust the tension of tension
disc No. 2
Adjust with the button clamp
ing lever jaw holder
Adjust the button clamping
pressure
First stitching thread
comes out on top of
button excessively
Inadequate adjustment
of tension lever
Adjust the nipper bar block,
rear
Thread cutting bad
at stop motion
Bad timing of tension
disc No. 2
Needle hitting the button
hole
Inadequate rising range
of button clamp
Nipper thread holding
bad
Button clamp pressure
too strong
Rotard the float timing of
tension disc and adjust the
thread tension
Reset the needle fall
Make the button clamp lever
jaw about 12m/m (15/32")
from lower plate
Adjust with nipper bar block
Adjust with button clamp
pressure adjusting nut
21 —
From the library of: Superior Sewing Machine & Supply LLC

JUKI MB-372 Specifications

General

Brand	JUKI
Model	MB-372
Category	Sewing Machine
Language	English