Brother BAS-705 Instruction Manual page 78

Problem
Upper thread breaks.
Skipped stitches occur.
Needle breaks.
Cause
Upper thread tension is
too strong.
Needle is installed
incorrectly.
Thread is too thick for
the needle.
Thread take-up spring
tension and height are
incorrect.
Damaged or burred
rotary hook, needle hole
plate or needle.
Thread path is incorrect.
Clearance between
needle and rotary hook
tip is too great.
Incorrect needle and
rotary hook timing.
Driver is contacting
needle more than is
necessary.
Needle is bent.
Needle is installed
incorrectly.
Thread is twisted too
strongly.
Needle is touching the
rotary hook.
Needle is bent.
Needle is too thin.
Needle moves about.
Feed plate fixing screw
is not correctly tightened.
Check
Upper thread tension
Needle direction
Thread and needle
Thread take-up spring
tension and height
Damage or burring
Thread
Needle clearance
Needle bar lift amount
Clearance between
driver and needle
Bent needle
Needle direction
Winding direction of
thread along thread path.
Needle clearance
Needle bar lift amount
Bent needle
Needle and thread
Needle and thread
Feed plate
75
10. TROUBLESHOOTING
Remedy
Adjust the upper thread
tension.
Install the needle so that
the groove is facing
forward.
Use the correct thread
for the needle.
Adjust the tension and
height of the thread
take-up spring.
File smooth or replace
the affected part.
Pass the thread correctly
along the thread path.
Increase the thread amount.
Adjust the needle
clearance.
Adjust the needle bar lift
amount.
Adjust the driver needle
guard.
Replace the needle.
Install the needle so that
the groove is facing
forward.
Set the correct thread
winding direction for the
thread path.
Adjust the needle
clearance.
Adjust the needle bar lift
amount.
Replace the needle.
Use the correct needle
for the material.
Select the correct needle
for the sewing conditions.
Reduce the sewing speed.
Install the feed plate
securely.
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BAS-705