Possible reasons: external power or plug fault, power failure.
Solution: replace the power supply.
Possible reasons: needle bending deformation, improper material
(too thick, too thin, too soft, too hard), wearing or not, the
wrong or wrong sewing thread, improper sewing thread, no standard
Solution: replace the original factory or standard 90 # machine
needle, correct the needle and tighten the thimble screw properly,
replace the appropriate fabric, and replace the sewing thread of
the original factory.