NLI DKN-3, Instruction Manual, Page: 15 / 40

11
Trouble Cause Cure
Needle thread breaks
1. Damaged looper
2. Needle thread too tight
3. Worn our feed dog causing fine stitches
4. Thread twisting or entangling between
thread stand and needle
5. Improper needle setting;
Bent or damaged needle
6. Needle thread too loose
Replace looper
Reduce tension
Replace feed dog
Secure correct threading
Set needle properly
Replace needle
Increase tension
Looper thread breaks
1. Looper thread too tight or too loose
2. Damaged looper
3. Thread twisting or entangling between
thread stand and looper
Adjust tension
Replace looper
Check for correct threading
No chaining on fabric end
1. Incorrect threading
2. Looper thread too tight
3. Improper timing of needle and looper
4. Presser foot screw loosened
Thread machine correctly
Reduce tension
Adjust timing of needle and looper
Tighten the screw
Thread skips
1. Needle setting not correct;
Bent or damaged needle
2. Needle thread regulator set too low
3. Needle thread sticking on needle due to
heat
4. Needle bar set too high
5. Needle thread pinched by needle guard,
collapsing loop
6. Looper thread too loose, not marking a
good triangle
Set needle correctly
Replace needle
Raise regulator
Use lubricant on thread
Lower needle bar
Lower needle guard slightly
Increase looper thread tension
Needle or looper breaks
1. Improper timing of needle and looper
2. Bent needle
Adjust timing of needle and looper
Replace needle
Nonuniform stitch length;
seam not straight
1. Weak pressure of needle and looper
2. Bent needle
3. Worn out feed dog
Increase pressure
Replace needle
Replace feed dog
7. Troubleshooting
When trouble occurs when operating the machine, refer to the following table for selecting suitable measures: