The Z-Motor on my K-8400 isn’t when i try to move it with the move axis 1mm command. it also doesnt move via auto home. However it is making a very high pitched sound. The z-rod seems to be very slightly bent but I can still turn it by hand quite easily. All wires are connected.
You may want to check and make sure all of the cable plugs are in the correct connectors.
Maybe re seat the cables just to be sure.
If your wiring is OK, try to swap the Z motor driver with another one and check if it’s working.
Thank you for the quick replys 
I will try your suggestions out tomorrow and then tell you if it worked.
switched the x and z driver boards now the z works and the x doesnt so i think my driver board is defect. thanks for your help
Do you know how to contact velleman for a replacement??
I will continue to post updates
Please mail your requirements and address to support at velleman dot be
Where can I mail them??
went to http:// www. velleman. eu/ support/ can’t find where to mail
as he wrote : support at velleman dot be
Im stupid thanks xD