Ramps/NEMA17 motor issues

I finally set up the the ramps board and soldered 3 motors. However, there have been some issues. When I decrease the z-value, the z-motor does not rotate, but it does rotate when I increase the the z-value up. Any ideas?

yep, areyour endstop plugged and working?
i guess if you send m119, it will say x triggered y triggered and z triggered.
If you want to continue your test, without plug in the end stop, you have to try, invert endstop logic in your firmware, so it will see them as open.
The fact is you can't go further than the eendstop.

Yep, Apparently Z_Min is showing as high. Thanks.