XLoader+grbl=motors moving all the time

Hello guys,I have been trying to get into gcode recently and I have found Tinkernut´s CR-Rom to cnc tutorial (https://www.youtube.com/watch?v=2xMfkTrx_0U) .Hardware part is ok but when I use XLoader to load hex file v0.8c from site https://github.com/grbl/grbl my motors starts to go 1 side forever. Only difference from video is that I use USB to power and H-Bridge to control motors. Any help please? Thank you for your time :)

Btw when I use standart arduino code all works well..So no problem in circuit itself.

It is usually a bad idea to power an Arduino and some motors from the same source. Certainly, most motors should not be powered by USB. Provide some other power source for your motors.

A video shows things working properly. You do the same as the video but with some differences AND things do not work so well. Could there be a connection?

Hey man thank you for reply.So I did connected motors to separated power sup. and motors seems to be working better BUT when I send code G0 z-1 (moves z axe up) but when I tell it G0 z0 nothing happens..and thats same for all motors :( Any wise help again please :)

I am glad to help but I do not know grbl and I do not know gcode. Sorry!

In any case, this probably deserves a new post with a different title.