motor problems with self resetting UMO

[dunc 0]

Hi this is my first problem since i got my UMO. i installed a new heat bed and it work fine and then the nozzle was replace then a few problems occurred.

now when i tried to level the bed and my z-axis will not move at all not up or down and I've tried moving it in the menu on the UMO, power is getting to it because when i try to moves by hand its locked it place, and when the UMO off i can move it.

When i try to print the heated bed and the extruder do not move but the x and y axis move perfectly.

then if a leave it for a minute it start resetting it self ever 5 to 10 seconds.

so i don't know what happening and i really need help on this please,

kind regard Duncan