Brother S-7000DD Instruction Manual page 44

8. TROUBLESHOOTING
Problem
5 Skipped stitches at sewing
start
Thread unravelling at
sewing start
6 Uneven seam
7 Large degree of puckering
(excess tension)
35
・ Is the thread take-up spring tension too strong?
Reduce the tension of the thread take-up spring.
・ Is the thread take-up spring operating range too large?
Lower the position of the thread take-up spring.
・ Are the trailing lengths of the upper threads too short after thread
trimming?
Adjust the pretension.
・ Are the threads not being trimmed cleanly?
Sharpen the fixed knives, or replace the fixed and movable
knives if necessary.
・ Is the needle too thick?
Try using a needle with a count that is one lower than the
current needle.
・ Is the length of thread trailing out from the bobbin case after thread
trimming too short?
If the bobbin is spinning loosely, replace the anti-spin spring in
the bobbin case.
・ Is the sewing speed too fast at the sewing start?
Set the operation panel so that slow start is enabled.
・ Is the needle up stop position too high?
Adjust the needle up stop position.
0749M
・ Is the presser foot pressure too weak?
Adjust the presser foot pressure.
・ Is the feed dog too low?
Adjust the feed dog height.
・ Is the bobbin scratched?
If the bobbin is damaged, smooth it with an oiled grindstone or
replace it.
0473M
・ Is the upper thread tension too strong?
Make the upper thread tension as weak as possible.
・ Is the lower thread tension too strong?
Make the lower thread tension as weak as possible.
・ Is the needle tip blunt?
Replace the needle if it is blunt.
・ Is the needle too thick?
Replace with as thin a needle as possible.
・ Are the thread take-up spring tensions too strong?
Make the thread take-up spring tension as weak as possible.
・ Is the thread take-up spring operating range too large?
Lower the position of the thread take-up spring to as low a
position as possible.
・ Is the presser foot pressure too strong?
Adjust the presser foot pressure.
・ Is the sewing speed too fast?
Gradually reduce the maximum sewing speed using the
operation panel.
・ Is the angle of the feed dog correct?
Tilt the front of the feed dog down slightly.
0978M
Possible cause
S-7000DD
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