Trouble shooting guide
Problem
Cause
Correction
Reference
Upper
thread
breaks
1. The machine is not threaded
correctly.
1. Rethread the upper thread.
11
2. The thread tension is too tight.
2. Reduce the thread tension (to
lower number).
18
3. The thread is too thick for the
needle.
3. Select a larger needle size.
15
4. The needle is not inserted
correctly.
4. Remove and reinsert the
QHHGOHÀDWVLGHWRZDUGVWKH
back).
14
5. The thread is wound around
the spool holder pin.
5. Remove the reel and wind up
the thread onto the reel.
11
6. The needle is damaged.
6. Insert a new needle.
14
Bobbin
thread
breaks
1. The bobbin case is not inserted
correctly.
1. Remove and reinsert the
bobbin case and pull on the
thread.
10
2. The bobbin case is threaded
wrong.
2. Check both bobbin and bobbin
case if on the correct position.
10
Skipped
stitches
1. The needle is not inserted
correctly.
1. Remove and reinsert the
QHHGOHÀDWVLGHWRZDUGVWKH
back).
14
2. The needle is damaged.
2. Insert a new needle.
14
3. The wrong size needle has
been used.
3. Choose a needle to suit the
thread.
15
4. The presser foot is not
attached correctly.
4. Check and attach it correctly.
16
5. The machine is not threaded
correctly.
5. Rethread the upper thread.
11
Needle
breaks
1. The needle is damaged.
1. Insert a new needle.
14
2. The needle is not correctly
inserted.
,QVHUWWKHQHHGOHFRUUHFWO\ÀDW
side towards the back).
14
3. Wrong needle size for the
fabric.
3. Choose a needle to suit the
thread and fabric.
15
4. The wrong presser foot is
attached.
4. Select the correct presser foot.
-
5. The needle clamp screw is
loose.
5. Use the screwdriver to tighten
the screw.
14
6. The presser foot is not
appropriate for the type of
stitch that you sew.
6. Attach appropriate presser foot
for the type of stitch that you
sew.
-
7. The upper thread tension too
tight.
7. Loosen the upper thread
tension.
18
49
Before calling for service, check below trouble shooting guides in advance, if problem
still exist, please contact nearest dealer or local service center.
Summary of Contents for Q421A
Page 1: ...Instruction Manual Q421A...
Page 2: ......
Page 7: ...Machine Introduction...
Page 11: ...Machine Setup...
Page 25: ...Sewing Basics...
Page 34: ...Utility Stitches...
Page 53: ...Maintenance and Trouble shooting...
Page 58: ......
Page 59: ......
