Brother BE-438C Instruction Manual page 65

Problem
Thread jamming.
Poor seam finish on
reverse side of
material.
Incorrect thread
tightness.
Button breaks.
Machine does not
operate when power is
turned on and foot
switch is depressed.
Cause
Thread take-up spring
tension and height are
incorrect.
Incorrect needle and
rotary hook timing.
Shuttle race thread guide
is not separating the
threads.
Shuttle race thread guide
is separating the threads
insufficiently.
Upper thread is not prop-
erly tight.
Uneven upper thread
length.
Upper thread is too long.
Needle is striking the
button.
Upper thread tension is
too weak.
Lower thread tension is
too weak.
Thread take-up spring
tension and height are
incorrect.
Needle is striking the
button.
Head position switch
does not work.
Check
Thread take-up spring
tension and height
Needle bar lift amount
Shuttle race thread guide
position
Shuttle race thread guide
position
Upper thread tension
Upper thread length
Thread take-up lever
stroke
Needle down setting
Upper thread tension
Lower thread tension
Thread take-up spring
tension and height
Needle down setting
Head position switch cord
connection
Switching plate position
Head position switch is
broken.
BE-438C
16. TROUBLESHOOTING
Remedy
Adjust the tension and
height of the thread take-
up spring.
Adjust the needle bar lift
amount.
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 thread take-up
lever stroke.
Refer to "6. 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.
Refer to "6. CHECKING
THE SEWING
PATTERN".
Check if the cord is dis-
connected.
Adjust the position of the
switching plate.
Replace the head posi-
tion switch.
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