Methods as below:
1. Change the needle first.
2. Drop the feeding teeth and see if there is pressure on the presser foot.
3. Open the two screws on the needle plate to remove the needle plate and follow:
(1) Shake the handwheel on the right side and shake the needle bar to the lowest position (when you shake it, don’t remember it)
(2) Continue to shake down to see the needle bar ascending, the lower shuttle also starts to hook the needle
(3) The hook tip is used to hook the needle thread. When it coincides with the needle eye, you must have a reference object. The tip of the shuttle is not hooked on the eye of the needle, but hooked up to 1.5-2.0mm on the eye of the needle.