Brother 434C Sewing Machine User Manual


 
6. TROUBLESHOOTING
KE-430B, 430C series
135
Problem Cause Remedy Ref.
Movable knife is blunt. Replace the movable knife.
P.118
-
P.120
Fixed knife is blunt. Sharpen or replace the fixed knife.
P.118
-
P.120
Adjust the position of the shuttle
race thread guide. (except KE-484C)
P.102
Movable knife does not pick up the
thread.
Adjust the needle bar lift amount. P.100
The movable knife does not pick up
the thread because of skipped
stitches at the sewing end.
Refer to “Skipped stitches occur”. P.134
Movable knife position is incorrect.
Adjust the position of the movable
knife.
P.116
P.117
Upper thread is not
trimmed.
Sub-tension is too weak.
Turn the sub-tension nut to adjust
the tension.
Instruction
manual
Thread take-up spring tension and
height are incorrect.
Adjust the tension and height of the
thread take-up spring.
P. 5
Incorrect needle and rotary hook
timing.
Adjust the needle bar lift amount. P.100
Thread jamming.
Shuttle race thread guide is not
separating the threads. (except
KE-484C)
Adjust the position of the shuttle
race thread guide.
P.102
Shuttle race thread guide is
parating the threads insufficiently.
(except KE-484C)
se
Adjust the position of the shuttle
race thread guide.
P.102
Upper thread is not properly tight. Adjust the upper thread tension. P.5
Uneven needle thread. Adjust the sub-tension.
Instruction
manual
Needle thread is too long.
Adjust the thread take-up lever
stroke.
P.114
P.115
Poor seam finish on
reverse side of
material.
Needle is striking the button (438)
Refer to “6. CHECKING THE SEWING
PATTERN” in the Instruction Manual.
Instruction
manual
Upper thread tension is too weak. Adjust the upper thread tension. P.5
Lower thread tension is too weak. Adjust the lower thread tension. P.5
Incorrect thread
tightness.
Thread take-up spring tension and
height are incorrect.
Adjust the tension and height of the
thread take-up spring.
P. 5
Check if the head position switch
cord is disconnected.
Instruction
manual
Adjust the position of the switching
plate.
P.130
Machine does not
operate when power
is turned on and foot
switch is depressed.
Head position switch does not work.
Replace the head position switch if
it is broken.
Inner clamping device
does not operate.
(434, 435, 436)
Work clamp pressure is too strong.
Adjust the work clamp pressure so
that the inner clamping device
operates.
P.132