Troubleshooting

Condition

 

Cause

Reference

The needle thread

1. The needle thread is not threaded properly.

See page 21

breaks.

2.

The needle thread tension is too tight.

See page 24

3.

The needle is bent or blunt.

See page 16

 

 

4.

The needle is incorrectly inserted.

See page 16

 

5.

The needle thread and the bobbin thread are not set under the

 

 

 

presser foot when starting sewing.

See page 25

 

6.

The threads are not drawn to the rear after sewing.

See page 82

 

7.

The thread is either too heavy or too fine for the needle.

See page 17

 

 

 

 

The bobbin thread

1.

The bobbin thread is not threaded properly in the bobbin holder.

See page 20

breaks.

2.

Lint has collected in the bobbin holder.

See page 82

 

 

3.

The bobbin is damaged and doesn't turn smoothly.

Exchange bobbin.

 

 

 

 

The needle breaks.

1.

The needle is incorrectly inserted.

See page 16

 

 

2.

The needle clamp screw is loose.

See page 16

 

3.

The threads are not drawn to the rear after sewing.

See page 25

 

4.

The needle is too fine for the fabric being used.

See page 17

 

 

 

Skipped stitches

1. The needle is bent, blunt or incorrectly inserted.

See page 16

 

2.

The needle and/or fabrics are not suitable for the work being

 

 

 

sewn.

See page 17

 

3.

A Blue Tip needle is not being used when sewing stretch, very

 

 

 

fine fabrics or synthetics.

See page 17

 

4.

The needle thread is not threaded properly.

See page 21

 

5.

A poor quality needle is being used.

Change the needle.

 

 

 

Seam puckering

1. The needle thread tension is too tight.

See page 24

 

2.

The needle thread is not threaded properly.

See page 21

 

3.

The needle is too heavy for the fabric being sewn.

See page 17

 

4.

The stitch length is too long for the fabric.

Make the stitch coarser

 

 

 

 

The cloth is not

1.

The feed dog is packed with lint.

See page 78

2.

The stitches are too fine.

Make the stitch coarser.

feeding smoothly.

3.

The feed dog is not raised after "drop feed" sewing.

See page 14

 

 

 

 

 

Stitches form loops

1.

The needle thread tension is too loose.

See page 24

2.

The needle is either too heavy or too fine for the thread.

See page 17

below the fabric.

 

 

 

 

 

 

The machine does not

1. The machine is not plugged in.

See page 6

2.

Thread has been caught in the hook race.

See page 82

work.

3.

The bobbin winder spindle is not returned to the left after bobbin

 

 

 

 

 

winding.

See page 19

 

 

 

 

Buttonhole is not sewn

1.

The stitch density is not suitable for the fabric being sewn.

See page 43

2. A suitable interface material has not been used for stretch or

 

properly.

 

synthetic fabric.

See page 17

 

 

 

 

The machine does not

1.

Thread has been caught in the hook race.

See page 82

run smoothly and is

2.

Lint has built up in the hook race or bobbin holder.

See page 82

noisy.

 

 

 

 

 

 

 

8 6

Page 88
Image 88
Janome 4900 QC manual Troubleshooting, Condition Cause Reference