If you put the fuse inline between the drive and stepper, there's a good chance you killed the drive. Never put a fuse there, and never disconnect a motor under power, or you'll kill the drive instantly.
If the drive is working correctly, the motors should lock up when power is aplied to the drive. If they don't, then either the drives are miswired, or dead. If they do lock up, then you can move on to Mach3.