Brother KE-430FX Instruction Manual page 86

11. TROUBLESHOOTING
Problem
Upper thread breaks.
Lower thread breaks.
Skipped stitches occur.
Needle breaks.
Button breaks.
(BE-438FX)
77
Cause
Upper thread tension is too strong.
Needle is installed incorrectly.
Thread is too thick for the needle.
Thread take-up spring tension and
height are incorrect.
Damaged or burred rotary hook, needle
hole plate or needle.
Thread melting (synthetic thread)
Lower thread tension is too strong.
Corners of needle hole plate or bobbin
case are damaged.
Clearance between needle and rotary
hook tip is too great.
Incorrect needle and rotary hook timing.
Driver is contacting needle more than is
necessary.
Needle is bent.
Needle is installed incorrectly.
Needle is touching the rotary hook.
Needle is bent.
Needle is too thin.
Needle is striking the button.
(BE-438FX)
Needle is striking the button.
KE-430FX/KE-430FS, BE-438FX
Remedy
Adjust the upper thread tension.
Install the needle correctly.
Use the correct thread for the needle.
Adjust the tension and height of the
thread take-up spring.
File smooth or replace the affected
part.
Use the needle cooler.
Adjust the lower thread tension.
File smooth or replace the affected
part.
Adjust the needle clearance.
Adjust the needle bar lift amount.
Adjust the driver needle guard.
Replace the needle.
Install the needle correctly.
Adjust the needle clearance.
Adjust the needle bar lift amount.
Replace the needle.
Use the correct needle for the material.
Refer to "5-6. Checking the sewing
pattern" .
Refer to "5-6. Checking the sewing
pattern" .
Ref.
P. 63
P. 26
P. 30
P. 64
P. 22
P. 63
P. 66
P. 66
P. 66
P. 26
P. 66
P. 66
P. 30
P. 42
P. 42