I'm having the same problem... wired up everything from the 4030/425oz kit and when I turn on the power the motors lock up like they should, but linux cnc and Mach-3 on different computers nothing turns. I know its not the parallel port (different computers) I know it isn't the parallel cable (multi-meter test). Power supply is putting out 24V to the drivers,so the only thing I can think of is the c-10 BOB. (At least one of the 4030s must be ok). Does anyone have an idea what could be wrong?