The fact that you cannot move the motors with the keyboard serves as a clue to a couple possibilities.
- The software may not be communicating with parallel port. (One possibility may be that your step pins are not low active, or vice versa depending on your drivers).
- You may not be in the correct tab of Mach3. Make sure you are in the Program Run tab.
- The jog on/off button on the program run screen may not be lit (invoked).
This address below shows the complete troubleshooting for this type of situation. It will show how to test each pin at the parallel port at the back of the computer and everything else associated with correctly wiring the electronics.
6 axis robot with Mach3 Card 6 Axis Motion Controller