- 37 -
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
17
Irregular stitches
- Incorrect size needle.
- Improper threading.
- Loosen 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
17
- Gently lead 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 not installed. The needle is curving.
- Pulling fabric.
- The needle clamp screw is loose.
- The pattern dial is rotated when needle is in 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 your choose a
pattern.
- Re-set presser foot.
Bunching of thread
- Upper and lower threads are not pulled back under
presser foot before starting seam.
- 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 type of thread.
- Bent or blunt needle.
- Loose presser foot
- Fabric too thin or too soft.
- Re-set thread tension. See page
17
- Re-thread. See page
14
- Use same size and type threads.
- Insert new needle.
- Re-set presser foot.
- Use underlay or vlies.
Skipping stitches
- Wrong needle size
- Bent or blunt needle.
- Incorrect setting of needle.
- Improper threading.
- Choose correct size needle for thread and fabric. See
page
19
- 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
17
- Re-set needle. See page
8
- Choose correct needle and thread to suit the fabric. See
page
19
- Adjust position of the indentation to right side.
See page
10
、
、
、
、
11
- Re-set bobbin case. See page
34
- Replace new needle.
- Sand or change bobbin case.
- Insert needle again
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
18
- Clean bobbin case and shuttle. See page
34
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
34
- Pull back upper and bobbin thread under of presser foot.
- Feed dog position up
Machine jamming
knocking noise
- Thread caught in shuttle.
- Remove and clean shuttle. See page
34
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
17
- Re-thread. See page
14
- Re-thread. See page
12
、
、
、
、
13
