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FAULT FINDING CHART
Problem
Probable cause Possible easy correction
Threads kink
together under the
fabric.
- Upper thread improper threading.
- Upper tension dial at O position.
- Re-thread. See page 14
- Increase upper thread tension. See page 18
Irregular stitches
- Incorrect needle size.
- Improper threading.
- Loose top thread tension
- Pulling fabric.
- Loose presser foot.
- Uneven wound bobbin
- Needle plate broken
- Choose correct size needle.
- Re-thread. See page 14
- Tighten top tension. See page 18
- Gently pull the fabric.
- Re-set presser foot.
- Re-wind bobbin. See page 10、
、、
、11
- Change needle plate.
Breaking needle
- Wrong needle size for the fabric.
- The needle is curving.
- Pulling fabric.
- The needle clamp screw is loose.
- Pattern dial rotation when needle is in the fabric.
- Loose presser foot.
- Choose a needle to suit the thread and fabric.
- Re-set needle. See page 8
- Gently pull the fabric.
- Tighten the needle clamp screw.
- Bring needle to its highest position, before you choose a
pattern
- Re-set presser foot.
Bunching of thread
- Upper and lower thread not pulled back under
presser foot before sewing.
- Pull both threads under and back of presser foot, then
rotate the hand wheel with right hand.
Puckering
- Incorrect thread tension.
- Upper thread improper threading.
- Using two different sizes or types of thread.
- Bent or blunt needle.
- Loose presser foot
- Fabric too thin or too soft.
- Re-set thread tension. See page 18
- Re-thread. See page 14
- Use same size and type threads.
- Insert new needle.
- Re-set presser foot.
- Use underlay or vlies.
Skipping stitches
- Incorrect size needle.
- Bent or blunt needle.
- Incorrect setting of needle.
- Improper threading.
- Choose correct needle size for thread and fabric. See
page 20
- Insert new needle.
- Re-set needle. See page 8
- Re-thread. See page 14
Breaking upper
thread
- Starting to stitch too fast.
- Improper threading.
- Top thread tension too high.
- Incorrect setting of needle.
- Wrong needles and thread for the fabric.
- Set thread pool and the position indentation at left
side.
- Incorrect setting of bobbin case.
- Needle eye is sharp.
- Burrs on bobbin.
- Burrs on needle hole.
- Start to stitch at a medium speed.
- Re-thread. See page 14
- Adjust top thread tension. See page 18
- Re-set needle. See page 8
- Choose correct needle and thread to suit the fabric. See
page 20
- Adjust position of the indentation to right side.
See page 10、
、、
、11
- Re-set bobbin case. See page 38
- Replace new needle.
- Sand or change bobbin case.
- Sand or change needle plate.
Breaking bobbin
thread
- Down thread improper threading.
- Down thread tension too high.
- Lint in bobbin or shuttle.
- Re-thread. See page 12、
、、
、13
- Adjust thread tension. See page 19
- Clean bobbin case and shuttle. See page 38
Fabric not moving
- Stitch length in “O” position.
- Scraps in with feed-dog
- Sewing thread entangled
- Feed dog position down.
- Adjust stitch length.
- Clean feed dog. See page 38
- Pull back upper and bobbin thread under presser foot.
- Feed dog position up.
Machine jamming
knocking noise
- Thread caught in bobbin case.
- Remove and clean bobbin case. See page 38
Sewing machine
doesn’t operate
- The machine is not plugged in.
- Machine is not switched on.
- Plug in machine.
- Switch on machine
Down thread is
pulled above the
cloth.
- Top thread tension too high.
- Upper thread improper threading.
- Down thread improper threading.
- Adjust top thread tension. See page 18
- Re-thread. See page 14
- Re-thread. See page 12、
、、
、13
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