Does anything work on tne mach3 screen ? If not maybe you did not click the RESET button which enables the controller. This will light the "computer" led on the machines control panel. If the LED is on then the machine sees the computer. Try typing in 500 for the S word and hit enter then click the spindle button. Or try typing M3 S500 into the MDI line and hit enter. If neither of those work it is time to start trouble shooting.