The bobbin thread cannot be pulled up.

Needle is turned, bent or the point is dull.

Replace the needle.
Refer to How do I change the needle ?
Bobbin is set incorrectly.

Reset the bobbin thread correctly.
Refer to How do I set the bobbin ?
Upper threading is incorrect.

Check the steps for threading the machine and rethread the machine correctly.
Refer to How do I thread the machine ?

FAQ e Risoluzione dei problemi