32
TROUBLESHOOTING
Trouble
Causes
Soultion
Top thread broken
1. Improper top threading.
2. Excessively tight top tension.
3. Blunt or bend needle.
4. Improper fixing of needle.
5. At start of sewing, top thread and
bottom thread are not correctly
fixed beneath the presser.
6. The thread is unsuitable.
1. Threading the top thread again.
2. Adjust the top tension.
3. Replace the needle.
4. Reinstall the needle.
5. Proper operation.
6. Replace the proper thread.
Bobbin thread broken
1. The bobbin thread is not correctly
threaded into bobbin case.
2. Cotton flock collected on shuttle
race.
3. The bobbin is damaged and
impossible to smoothly rotate.
1. Thread the bobbin thread again.
2. Clean the shuttle race.
3. Replace the bobbin.
Needle broken
1. Improper fixing of needle.
2. Blunt or bend needle.
3. The needle clamp screw is
loosening.
4. Excessively tight top tension.
5. Too thin needle.
1. Reinstall the needle.
2. Replace the needle.
3. Tight the needle clamp screw.
4. Adjust the top tension.
5. Replace the proper needle.
Skipping stitches
1. Improper fixing of needle.
2. Blunt or bend needle.
3. The needle and (or) thread is
unsuitable for the used fabric.
4. Improper top threading.
5. The needle is unsuitable.
1. Reinstall the needle.
2. Replace the needle.
3. Replace the proper needle and
thread.
4. Threading the top thread again.
5. Replace the proper needle.
Seam puckering
1. Excessively tight top tension.
2. Improper top threading.
3. Excessively thick top thread for
the used fabric.
1. Adjust the top tension.
2. Threading the top thread again.
3. Replace the proper thread.
Unsmooth feed
1. Feed dog is wound by thread.
2. Thread jams.
1. Clean the feed dog.
2. Clean the clamping thread.
Not run of machine
1. Not surely inserting power plug.
2. Clamping thread at shuttle race.
3. Failure to replace the bobbin
winder shaft at original position
after winding bobbin.
1. Check the power connector.
2. Clean the clamping thread.
3. Push the bobbin winder shaft to
original position.
Thread jaming
1. The presser foot lifter is not lower
down when sewing.
2. Improper top threading.
3. Improper bobbin threading.
1. Lower down the presser foot lifter.
2. Threading the top thread again.
3. Threading the bobbin thread
again.
