Brother 484C Sewing Machine User Manual


 
6. TROUBLESHOOTING
KE-430B, 430C series
134
Problem Cause Remedy Ref.
Upper thread tension is too strong. Adjust the upper thread tension. P.5
Needle is installed incorrectly. Install the needle correctly.
Instruction
manual
Thread is too thick for the needle.
Use the correct thread for the
needle.
P. 5
Thread take-up spring tension and
height are incorrect.
Adjust the tension and height of the
thread take-up spring.
P. 5
Damaged or burred rotary hook,
needle hole plate or needle.
File smooth or replace the affected
part.
Upper thread breaks.
Thread melting (synthetic thread)
Use a thread cooling device
(optional)
P.136
Lower thread tension is too strong. Adjust the lower thread tension. P.5
Lower thread breaks.
Corners of needle hole plate or
bobbin case are damaged.
File smooth or replace the affected
part.
Clearance between needle and
rotary hook tip is too great.
Adjust the needle clearance. P.101
Incorrect needle and rotary hook
timing.
Adjust the needle bar lift amount. P.100
Driver is contacting needle more
than is necessary. (except KE-484C)
Adjust the driver needle guard. P.101
Needle is bent. Replace the needle.
Needle is installed incorrectly. Install the needle correctly.
Instruction
manual
Skipped stitches
occur.
Needle thread is too short.
Adjust the thread take-up lever
stroke.
P.114
P.115
Adjust the needle clearance. P.101
Needle is touching the rotary hook.
Adjust the needle bar lift amount. P.100
Needle is bent. Replace the needle.
Needle is too thin.
Use the correct needle for the
material.
P. 5
Needle breaks.
Needle is striking the button (438)
Refer to “6. CHECKING THE
SEWING PATTERN” in the
Instruction Manual.
Instruction
manual
Button breaks. (438)
Needle is striking the button
Refer to “6. CHECKING THE
SEWING PATTERN” in the
Instruction Manual.
Instruction
manual