2
Condition
Cause
How to Fix
Reference
3. Breaking
upper
thread.
1. Initial sewing speed is
too fast.
2. Thread path is incorrect.
3. Needle is bent or dull.
4. Top tension is too strong.
5. Needle size is inappropriate for
fabric.
6. Needle eye is worn.
7. Needle hole in needle
plate is
worn or burred.
Start with medium speed.
Use the proper thread path.
Replace with a new needle.
Adjust top tension correctly.
Use appropriate needle for fabric and
thread in use.
Change the needle.
Repair the hole or replace the needle
plate.
4. Breaking
bobbin
thread.
1. Bobbin holder is incorrectly
threaded.
2. Too much thread is wound
on the bobbin.
3. Lint is stuck inside the bobbin
holder.
4. Thread quality is too low.
5. Thread is jamming around the
bobbin holder.
Set the bobbin thread correctly.
Adjust the position of bobbin winder
stopper.
Clean the bobbin holder.
Change to a high quality sewing thread.
Clear out the jamming thread.
5. Needle
breaks
1. Needle is hitting the needle plate.
2. Needle is bent or worn.
3. Needle is hitting the hook.
4. Fabric is being pulled too strongly
while sewing.
See mechanical adjustment “Needle drop
position”.
Change the needle.
See mechanical adjustment “Clearance
between needle and tip of the rotary
hook”.
Guide the fabric gently while sewing.
P. 9
P. 12
