How to repair the computer sewing machine that bounces up after thread cutting?

After sewing, the thread behind the thread will automatically pull back and cause loosening.

With automatic knotting function, it can be used before stopping the needle.

Then there is the automatic thread cutting function, which can be used directly.

No sideline business will break up.

Without the above functions.

I sewed three stitches to fix it.

Even if the upper thread is pulled back, it will not come loose.

In addition, please adjust the offline tension, it is easy to pull back if it is too tight.