Innov-is F420

FAQs & Troubleshooting

FAQs & Troubleshooting

Tangled thread on wrong side of fabric


  • The thread becomes tangled on the wrong side of the fabric.


  • After starting sewing, a rattling noise is made and sewing cannot continue.
  • Looking under the fabric, there is tangled thread in the bobbin case.


Incorrect upper threading

If the upper thread is incorrectly threaded, the upper thread passed through the fabric cannot be firmly pulled up and the upper thread becomes tangled in the bobbin case, causing a rattling noise.


Remedy / Check details

Remove the tangled thread, and then correct the upper threading.


  1. Turn off the sewing machine.


  2. Remove the tangled thread. If it cannot be removed, cut the thread with scissors.



  3. Remove the upper thread from the machine.

    If the bobbin was removed from the bobbin case,  install the bobbin in the bobbin case correctly.
    Refer to How do I set the bobbin?.


  4. Turn on the sewing machine.


  5. Raise the presser foot using the presser foot lever.

    (1) Presser foot lever

    The upper thread shutter opens so the machine can be threaded.
    If the presser foot is not raised, the machine cannot be threaded correctly.

  6. Press image (Needle position button) once or twice to raise the needle.

    The needle is correctly raised when the mark on the handwheel is at the top, as shown below. Check the handwheel and, if this mark is not at this position, press image (Needle position button) until it is.

    image (1) Mark on handwheel

  7. While holding the thread lightly with your right hand, pull the thread with your left hand, and then pass the thread behind the thread guide cover and to the front.

    (1) Thread guide cover


  8. While holding the thread lightly with your right hand, pass the thread under the thread guide plate, and then pull it up.


    (1) Thread guide plate


  9. Pass the thread through the thread channel in the order shown below.

    (1) Shutter

  10. Press image.


  11. Slide the thread behind the needle bar thread guide.
    The thread can easily be passed behind the needle bar thread guide by holding the thread in your left hand, then feeding the thread with your right hand, as shown. Make sure that the thread is passed through to the left of the tab of the needle bar thread guide.

    (1) Needle bar thread guide

    (2) Tab


  12. Pull the end of the thread, which has been passed through the needle bar thread guide, to the left, then pass the thread through the notch of the threader thread guide(A), and then firmly pull the thread from the front and insert it into the slit of the threader thread guide disk marked “7” all the way(B).
    Make sure that the thread passes through the notch of the threader thread guide.
    (1) Notch of the threader thread guide

    (2) Threader thread guide disk


  13. Cut the thread with the cutter on the left side of the machine.
    image (1) Cutter
    • If the thread is pulled through and cannot be cut correctly, lower the presser foot lever so that the thread is held in place before cutting the thread. If this operation is performed, skip step 14.
    • When using thread that quickly winds off the spool, such as metallic thread, it may be difficult to thread the needle if the thread is cut. Therefore, instead of using the thread cutter, pull out about 8 cm (approx. 3 inches) of thread after passing it through the threader thread guide disks (marked “7”).
    (1) 8cm (approx. 3 inches) or more

  14. Lower the presser foot lever to lower the presser foot.
    image (1) Presser foot lever


  15. Lower the needle threader lever on the left side of the machine until it clicks, and then slowly return the lever to its original position.
    image (1) Hook

    (2) Needle threader lever

    The hook is rotated and passes the thread through the eye of the needle.
    If the needle is not raised to it's highest position, the needle threader cannot thread the needle.

    Turn handwheel counterclockwise until the needle is at its highest position.

    image (1) Mark on handwheel
  16. Carefully pull the end of thread that was passed through the eye of the needle.

    If the needle was not completely threaded, but a loop in the thread was formed in the eye of the needle, carefully pull the loop through the eye of the needle to pull out the end of the thread.
    image (1) Loop of the thread

    When pulling out the thread, do not pull it with extreme force, otherwise the needle may break or bend.

  17. Raise the presser foot lever, pass the end of the thread through and under the presser foot, and then pull out about 5 cm (approx. 2 inches) of thread toward the rear of the machine.
    image (1) 5 cm (approx. 2 inches)


  18. Press image to unlock all keys and buttons.

If your question was not answered, have you checked other FAQs?

Have you checked the manuals?

If you need further assistance, please contact Brother customer service:

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Innov-is F420

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