There could be several things that could cause the machine not to pick up the bobbin thread.

• The upper thread could be tangled. Remove the thread completely from the machine.
  The correct size spool cap should be used for the size of the thread spool. Re-thread the machine according to the directions in the manual.

One Point Advice  Place a spool of thread on a spool pin
One Point Advice  Upper threading

• Remove the bobbin and make sure the bobbin is threaded properly in the shuttle race.
  Remove any loose threads or lint in the shuttle race.

One Point Advice  Lower(bobbin) threading

• You could be holding the needle thread too tight. Hold the thread lightly to keep the end from going down into the shuttle.
  
  
• The needle could be thread incorrectly. Thread the needle eye from the front to the back.
  
  
• The needle could be bent or improperly inserted. Install a new needle with the flat side of the needle facing the back.
  
  
• The thread twist is either too tight or too loose. Improper twisting results in irregular loop formation. Try using a new spool.