Check for the following matters.

• Probable cause

  The threading on the machine is improper.

   

  Remedy

  Make sure that the threads are passed into the machine properly.
  Rethread the threads to the machine in an appropriate procedure.

   

  Refer to the detailed instructions to learn the threading procedure.

  Instructions for threading the machine.

  You can also see the instructions for threading on movie.

  Video instructions for threading

• Probable cause

  The top cover spreader and top cover thread guide are attached incorrectly.

   

  Remedy

  Make sure that the top cover spreader and top cover thread guide are attached properly.
  Reattach the top cover spreader and top cover thread guide to the machine in an appropriate procedure.

   

  Refer to the instructions to learn the installation procedure of the top cover spreader and top cover thread guide in the threading procedure.

  Instructions for installing the top cover spreader and top cover thread guide in the threading procedure.

  You can also see the instructions for attaching the top cover spreader and top cover thread guide on movie.
  Refer to the operation in the first half of the movie "How to thread the top cover stitch" to learn attaching the top cover spreader and top cover thread guide.

  Video instructions: "How to thread the top cover stitch".

• Probable cause

  Adjustment of thread tension is not performed properly.

   

  Remedy

  Position "4" on the tension dial is the standard of thread tension.
  Start the adjustment with "4" when adjusting thread tension.
  When adjusting the thread tension, change the tension dial position little by little and then check the sewing result with trial sewing.

   

  Refer to the instructions to learn the adjustment of thread tension.

  Instructions for adjustment of thread tension

• Probable cause

  The top cover thread is not passed under the presser foot when you start sewing.

   

  Remedy

  If the thread for top cover is not underneath the pressor foot, the spreader sometimes does not catch the thread.
  Pass the top cover thread under the presser foot from left to right as shown in the illustration.