Brother BAS-705 - Troubleshooting; Machine Head Troubleshooting

10. TROUBLESHOOTING
10. TROUBLESHOOTING
10-1. Machine Head
― 74 ―
BAS-705
Thread winding amount
Upper thread length
Refer to "Skipped
stitches occur".
Bobbin winder thread
tension stud height
Thread wiper position
Clearance between
thread wiper and needle
tip
Thread wiper standby
position
Presser lifter air tube
Presser lifter air tube

Presser lifter air tube is
bent or damaged.
Presser lifter air tube is
bent or damaged.
Presser is contacting
thread wiper.
The thread wiper is
obstructing the needle.
Thread wiper position is
incorrect.
Bobbin winder thread
tension stud height is
incorrect.
Bobbin presser position
is incorrect.
Stitches being skipped
at the sewing start.
Uneven upper thread
length.
Lower thread winds to
one side.
Adjust the height of the
thread tension stud.
26
Adjust the position of the
bobbin presser.
26
Refer to "Skipped
stitches occur".

Adjust the sub-tension.
28
28
Adjust the operating
distance of the thread
wiper.
45
Adjust the height of the
thread wiper.
45
Adjust the position of the
thread wiper.
45
Straighten the bend in the
tube or replace the tube.
7
Straighten the bend in the
tube or replace the tube.
7

Page
Thread wiper does not
operate correctly.
Presser does not rise.

Problem
Lower thread winding
amount is incorrect.
Cause Check Remedy
Threads comes
unthreaded.



Tension and height of
thread take-up spring
Thread and needle Needle is too thick for
the thread.
Incorrect height or tension
of thread take-up spring.
Select a needle that matches the thread.
Check that the thread path. gives the
correct amount of resistance to the thread.
Increase the tension or
lower the height of the
thread take-up pring.
29
Damage
Lower thread tension Lower thread tension is
too strong.
Damaged or burred needle hole
plate, bobbin case corner, shuttle
race thread guide or shuttle race.
Adjust the lower thread
tension.
28
File smooth or replace
the affected part.

Lower thread breaks.
Lower thread tension
Bending amount of
bobbin presser spring
Tension of bobbin
presser spring in bobbin
case is too strong.
Lower thread winding
method is incorrect.
Reduce the tension of
the bobbin presser spring.
28
Adjust the lower thread
tension.
26.28