Owner's Manual

14. Troubleshooting
55
BAS-343E
Upper thread tension
Needle direction
Needle clearance
Thread and needle
Thread
Thread take-up spring
tension and height
Clearance between
driver and needle
Needle bar lift amount
Check Remedy Problem Cause
Thread is too thick for
the needle.
Upper thread tension
is too strong.
Thread take-up spring
tension and height are
incorrect. incorrect.
Thread path is incorrect.
Corners of needle hole
plate or bobbin case
are damaged.
Clearance between
needle and rotary hook
tip is too great.
Incorrect needle and
rotary hook timing.
Needle is installed
incorrectly.
Driver is contacting
needle more than is
necessary.
33
32
33
10
13
12
9
Adjust the upper
thread tension.
Adjust the driver
needle guard.
Adjust the needle
clearance. the affected
Pass the thread
correctly along the
thread path.
Adjust the needle bar
lift amount.
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.
Install the needle so
that the groove is
facing forward.
13
Page
Upper thread breaks.
Skipped stitches



Needle direction
Bent needle
Needle is bent.
9
Install the needle so
that the groove is
facing forward.tube.
Replace the needle.
Needle clearance
Bent needle
Needle bar lift amount
Needle is bent.
Needle moves about.
Neelde is touching the
rotary hook.
33
32

Replace the needle.
Adjust the needle
clearance. the groove
Adjust the needle bar
lift amount.
Needle breaks.
Needle and thread
Needle and threa
Needle is too thin.
12
12
Use the correct needle
for the material.
Select the correct needle
for the sewing conditions.
Reduce the sewing
Damage
Lower thread tension
Lower thread tension
is too strong.
13

File smooth or replace
the affected part.
Adjust the lower thread
tension. amount.
Lower thread breaks.
Thread melting
(synthetic thread)
Damaged or burred
rotary hook, needle
hole plate or needle.
Use a thread cooling
device.
Thread edge
Damage or burring
Needle is installed
incorrectly.
10