Troubleshooting - Brother KE-430B Service Manual

6. TROUBLESHOOTING

６. TROUBLESHOOTING
Turn off the power switch and disconnect the power cord before carrying out troubleshooting, otherwise
the machine will operate if the foot switch is depressed by mistake, which could result in injury.
Problem
Work clamp does not
rise.
Button clamp does
not rise. (438)
Work clamp is not
lowered.
Button clamp is not
lowered. (438)
Work clamp lift
amount is incorrect.
Button clamp lift
amount is incorrect.
(438)
Work clamp does not
close. (432)
Thread wiper does
not operate correctly.
Lower thread winds
to one side.
Lower thread winding
amount is incorrect.
Thread comes
unthreaded.
133
CAUTION
Cause
<430, 431, 433, 434, 435, 436, 484>
Work clamp operation is sluggish.
Work clamp (Button clamp) lift
amount is too great.
Too much friction between work
clamp plate and work clamp arm
lever plate. (430, 431, 433, 434
solenoid specifications)
Work clamp is contacting thread
wiper.
Presser lifter link is not moving
back.
<Solenoid specifications>
Incorrect position of work clamp arm
lever plate (button clamp holder
hook assembly).
<Pneumatic specifications>
Incorrect position of work clamp arm
lever.
Incorrect position of presser closing
roller.
The thread wiper is obstructing the
needle.
Thread wiper position is incorrect.
Tension stud height is incorrect.
Bobbin presser position is incorrect.
Stitches being skipped
sewing start.
Uneven needle thread.
Needle thread is too short.
KE-430B, 430C series
Remedy
Grease the sliding part of the work
clamp.
Adjust the work clamp (button
clamp) lift amount.
Grease the work clamp plate and
work clamp arm lever plate.
Adjust the position of the thread
wiper.
Check if the link return spring is
unhooked.
Adjust the work clamp (button
clamp) lift amount.
Check whether
engaged with
adjusting plate or not, and adjust
the position of presser closing roller.
Adjust the height of the thread
wiper.
Adjust the operating distance of the
thread wiper.
Adjust the operating distance of the
thread wiper.
Adjust the height of the tension
stud.
Adjust the position of the bobbin
presser.
at the
Refer to "Skipped stitches occur"
Adjust the sub-tension.
Adjust the thread take-up lever
stroke.
Ref.
P.104
P.105
P.104
P.105
P.106
P.104
P.105
P.111
-
P.113
P.65
-
P.68
P.104
P.105
P.106
stop lever is
stop position
P.108
P.111
-
P.113
P.111
-
P.113
P.111
-
P.113
Instruction
manual
Instruction
manual
P.134
Instruction
manual
P.114
P.115