How to fix the trembling extruder of A5S?

This problem is that the wire of the extrude motor  is loose .

Firstly, do a pull and insert of the plug, make sure it's tight .

Secondly, pull and insert the plugs of the three cables at the right side.

Thirdly,  open the y-box and check whether the wire of extrude motor  is loose .

Here is a video link for how to open the y-box .

https://www.youtube.com/watch?v=m1SS6x40NNY&list=PL1RCkPuTzWlLds9UmsdzRpNiav6Gdv4_F&index=4&t=0s

Lastly, plug the extrude wire.

Thanks.