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