S-7000DD
8. TROUBLESHOOTING
36
Problem Possible cause Page
8 Material slippage
・ Is the presser foot pressure too strong?
Adjust the presser foot pressure.
9 Lower thread is tangled at
the sewing start.
Spinning of bobbin during
thread trimming
・ Is the bobbin spinning direction correct when the lower thread is
being pulled?
Set the bobbin so that it turns in the opposite direction to the
rotary hook.
・ Is there too much thread
wound onto the bobbin?
The bobbin winding
amount should not be
more than 80 %.
・ Is the anti-spin spring attached?
Attach the anti-spin spring.
・ Is the bobbin turning smoothly?
If the bobbin is not turning smoothly, replace the bobbin.
・ Is a bobbin other that the light-alloy bobbins specified by Brother
being used?
Use only bobbins which are specified by Brother.
10 Upper and lower threads
are breaking.
・ Is the needle bent or is the needle tip broken?
Replace the needle if it is bent or broken.
・ Is the needle properly installed?
If it is incorrect, install the needle correctly.
・ Is the machine properly threaded?
If it is incorrect, thread the thread correctly.
・ Is the upper or lower thread tension too weak or too strong?
Adjust the upper thread or lower thread tension.
・ Is the upper thread may be loose because the thread take-up spring
operating range is too small?
Adjust the position of the thread take-up spring.
・ Is the rotary hook, feed dog or other part damaged?
If they are damaged, smooth them with an oiled grindstone or
replace the damaged parts.
・ Is the thread path damaged?
If the thread path is damaged, smooth it with sandpaper or
replace the damaged part.
26
26*
*
*
11 Incorrect thread trimming
(Upper and lower threads
are both not being
trimmed)
・ Is the fixed knife or movable knife damaged or worn?
Replace the fixed knife or the movable knife.
27*
12 Incorrect thread trimming
(Upper thread or lower
thread is not being
trimmed)
・ Is the needle properly installed?
If it is incorrect, install the needle correctly.
・ Is the fixed knife or movable knife blunt?
Replace the fixed knife or the movable knife.
27*
0750M
Lower
thread
2124M
0751M
0471M
