Hi I have a Sabre 1250 machine and when i start it up it goes through all of its self tests just fine, but then once its to the point where I can use the keys and screen I get an error 160 Z axis open loop, and when I go to the machine setup screen and view the current positions the Z axis is going continuously negative even though the physical axis is not moving. Has anyone had this problem or have any ideas on what I should be checking to fix it?

Thanks for the help, Joe