|
Symptom |
Root Cause |
Corrective Action
|
Sewing machine
suddenly stops during sewing.
Light is on, and handwheel can be turned easily by hand. |
|
| Sewing machine has been
run at a low speed for an extended period of time. |
| To prevent overheating,
motor power is automatically turned off. |
|
| Turn power off and wait
about 20 minutes. Safety device will reset, and machine will be ready to
operate. |
|
|
Needle will not move. |
| Upper thread has run
out. |
| Presser foot is up.
|
| Bobbin winder shaft was
left in winding position. |
| Buttonhole lever was not
lowered when machine was placed in buttonhole mode. |
|
| Replace empty spool and
thread machine. |
| Lower presser foot.
|
| Move bobbin winder shaft
back fully to left. |
| Lower buttonhole lever. |
|
|
Sewing machine will not run. |
| Presser foot is not
correct one, and needle hits presser foot. |
| Needle has come out and
is in hook of machine. |
|
| Replace presser foot
with new one. |
| Remove needle and insert
new one. |
|
|
Upper thread breaks. |
| Threading is not
correct. |
| Thread has a knot in it.
|
| Thread tension is too
tight. |
| Needle is bent or blunt
or has a sharp eye. |
| Needle is wrong size.
|
| Needle has been inserted
wrong. |
| Needle and thread does
not match. |
| Starting to stitch too
fast. |
| Thread take-up lever has
not been threaded. |
|
| Correctly thread
machine. |
| Remove knot.
|
| Correct thread tension.
|
| Replace needle.
|
| Replace needle with
correct size. |
| Properly insert needle.
|
| Start machine at a
medium speed. |
| Use proper thread or
needle. |
| Check threading order. |
|
|
Bobbin thread breaks. |
| Bobbin has not been
fully inserted in bobbin case. |
| Bobbin has been
incorrectly threaded. |
| Bobbin does not turn
smoothly in bobbin case. |
| Lint in bobbin case or
shuttle. |
|
| Securely install bobbin
into bobbin case. |
| Correctly thread bobbin
case. |
| Check to see that bobbin
has been wound evenly. |
| Clean bobbin case and
shuttle. |
|
|
Skipped stitches. |
| Thread tension is too
tight. |
| Needle is bent or blunt.
|
| Needle is wrong size. |
| Needle and thread does
not match. |
| Thread take-up lever has
not been threaded. |
| Light pressure on
presser foot. |
| Incorrect setting of
needle. |
|
| Correct thread tension.
|
| Replace needle.
|
| Replace needle with
correct size. |
| Use proper thread or
needle. |
| Check threading order.
|
| Increase pressure on
presser foot. |
| Reset needle. |
|
|
Stitches are not formed properly. |
| Thread has not been
pulled into thread sensor guide. |
| Threading is not
correct. |
| Bobbin case has been
threaded wrong. |
| Spool cap is wrong size
for thread spool. |
|
| Fully pull thread into
thread sensor guide. |
| Correct threading.
|
| Correctly thread bobbin
case. |
| Replace the cap with
correct size. |
|
|
Irregular stitches. |
| Incorrect size needle.
|
| Improper threading.
|
| Loose upper thread
tension. |
| Pulling fabric.
|
| Light pressure on
presser foot. |
| Loose presser foot. |
| Unevenly wound bobbin. |
|
| Choose correct size
needle for thread and fabric. |
| Rethread machine.
|
| Tighten upper thread
tension. |
| Do not pull fabric;
guide it gently. |
| Increase pressure on
presser foot. |
| Reset presser foot.
|
| Rewind bobbin. |
|
|
Fabric puckers. |
| Stitch length is too
long for material. |
| Needle point is blunt.
|
| Incorrect thread
tension. |
| Light pressure on
presser foot. |
| Fabric is too sheer or
soft. |
| Using two different
sizes or kinds of thread. |
|
| Decrease stitch length.
|
| Replace needle.
|
| Reset thread tension.
|
| Increase pressure on
presser foot. |
| Use underlay of tissue
paper. |
| Upper thread and bobbin
thread should be the same size and kind. |
|
|
Bunching of thread. |
| Upper and lower threads
not drawn back under presser foot. |
| Feed dog down. |
|
| Draw both threads back
under presser foot. |
| Raise feed dog. |
|
|
Needle breaks. |
| A thin needle was used
for sewing a heavy weight material. |
| Needle has not been
fully inserted into needle bar. |
| Needle clamp screw is
loose. |
| Presser foot is not
correct one. |
| Presser foot is loose.
|
| Pulling on fabric as you
sew. |
|
| Use correct size needle.
|
| Properly insert needle.
|
| Securely tighten needle
clamp screw. |
| Use correct presser
foot. |
| Reset presser foot.
|
| Do not pull fabric,
guide it gently. |
|
| Loud noise is heard.
|
| Knocking noise,
machine jammed. |
|
| Dust has accumulated in
feed dogs. |
| Lint is in hook.
|
| Thread caught in
shuttle. |
|
| Clean machine.
|
| Clean machine.
|
| Disassemble machine and
clean shuttle. |
|
|
The machine does not feed material. |
| The stitch length has
been set to zero. |
| The presser foot
pressure is too low. |
| Feed dogs are lowered.
|
| Threads are knotted
under fabric. |
|
| Reselect the proper
stitch pattern and length. |
| Set presser foor
pressure adjustment lever to "normal". |
| Raise feed dogs.
|
| Place both threads back
under presser foot before beginning to stitch. |
|
| Threading cannot be
done. |
| The needle threader
will not turn. |
| The threading hook
will not enter needle eye. |
|
| The needle is not in
highest position. |
| The needle threader is
designed not to turn to protect itself if the needle is not up.
|
| The needle has not been
fully inserted into needle bar. |
|
| Turn hand wheel until
needle reaches its highest position. |
| Properly insert needle. |
|
| Needle threader
cannot be returned and the sewing machine stops. |
| The threading hook is
left in the needle eye. |
|
Sewing machine was accidentally started while
threading hook was still in needle eye (during threading). |
Slightly turn handle clockwise and remove
threader. |