Brother KE-430HX Instruction Manual page 107

Problem
Upper thread is not
trimmed.
Thread jamming.
Poor seam finish on
reverse side of
material.
Incorrect thread
tightness.
Machine does not
operate when power is
turned on and foot
switch is depressed.
The illumination
becomes momentarily
darker or flickers.
Cause
Movable knife is blunt.
Fixed knife is blunt.
Movable knife does not pick up the
thread.
The movable knife does not pick up the
thread because of skipped stitches at
the sewing end.
Movable knife position is incorrect.
Sub-tension is too weak.
Thread take-up spring tension and
height are incorrect.
Incorrect needle and shuttle hook
timing.
Shuttle race thread guide
separating the threads.
Shuttle race thread guide is separating
the threads insufficiently.
Upper thread is not properly tight.
Uneven needle thread.
Needle thread is too long.
Needle is striking the button.
(BE-438HX/HS)
Upper thread tension is too weak.
Lower thread tension is too weak.
Thread take-up spring tension and
height are incorrect.
Machine head switch does not work.
The illumination may
momentarily darker or flicker when the
sewing machine starts
depending on the power supply in the
environment where the sewing machine
is being used. This is not a sign of a
malfunction.
KE-430HX/KE-430HS, BE-438HX/BE-438HS
Replace the movable knife.
Sharpen or replace the fixed knife.
Adjust the position of the shuttle race
thread guide.
Adjust the needle bar lift amount.
Refer to "Skipped stitches occur".
Adjust the position of the movable knife.
Turn the sub-tension nut to adjust the
tension.
Adjust the tension and height of the
thread take-up spring.
Adjust the needle bar lift amount.
is not Adjust the position of the shuttle race
thread guide.
Adjust the position of the shuttle race
thread guide.
Adjust the upper thread tension.
Adjust the sub-tension.
Adjust the sub-tension.
<When using the thread nipper
device>
Turn the tension nut to adjust the upper
thread trailing length to 35 – 38 mm.
Refer to "5-11. Checking the sewing
pattern".
Adjust the upper thread tension.
Adjust the lower thread tension.
Adjust the tension and height of the
thread take-up spring.
Check if the machine head switch cord
is disconnected.
Adjust the position of the switching
plate.
Replace the machine head switch if it is
broken.
become
or stops,
11. TROUBLESHOOTING
Remedy Ref.
P. 86
P. 86
P. 85
P. 84
P. 96
P. 86
P. 36
P. 82
P. 84
P. 85
P. 85
P. 81
P. 36
P. 38
P. 57
P. 81
P. 81
P. 82
P. 22
P. 30
97