Brother BAS-311F-L - Manual (Page 77)

14. TROUBLESHOOTING
BAS-311F-0, 311F-L, 326F-0
70
Needle bar lift amount
Upper thread is not
trimmed.
The movable knife does not pick
up the thread because of skipped
stitches at the sewing end.
Skipped stitches at
sewing end
Movable knife position
is incorrect.
Movable knife position
Adjust the needle bar lift
amount.
Refer to “Skipped
stitches occur”.
Adjust the position of the
movable knife.
44
42
Shuttle race thread
guide position Adjust the position of the
shuttle race thread gudie.
43
Sub-tension is too weak. Sub-tension
Turn the sub-tension nut
to adjust the tension.
25
Movable knife does not
pick up the thread.
Fixed knife is blunt. Fixed knife blade
Sharpen or replace the
fixed knife.
Thread take-up spring
tension and height are
incorrect.
Thread take up spring
tension and height
Thread jamming.
Incorrect needle and
rotary hook timing.
Needle bar lift amount
Shuttle race thread guide
is not separating the
threads.
Shuttle race thread
guide position
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.
42
43
25
Shuttle race thread
guide is not separating
the threads.
Shuttle race thread
guide position
Poor seam finish on
reverse side of material. Upper thread is not
properly tight. Upper thread tension
Uneven upper thread
length. Upper thread length
Adjust the position of the
shuttle race thread guide.
Adjust the upper thread
tension.
Adjust the sub-tension.
25
25
43
Upper thread tension is
too weak. Upper thread tension
Incorrect thread
tightness. Lower thread tension is
too weak. Lower thread tension
Thread take-up spring
tension and height are
incorrect.
Thread take up spring
tension and height
Adjust the upper thread
tension.
Adjust the lower thread
tension.
Adjust the tension and
height of the thread take-
up spring.
25
25
25
Problem Cause Check Remedy Page