Check that you have power to the 4 drive cards inside the Accumove 3 box, there will be a green light on each card. There is a fuse on the small power board with the two large capacitors, next to the two-pin plug that has the two red wires on it, this is an 8 amp 250v slow blow fuse. You can also check the two cards inside the black box inside Accumove box one of the cards has 4 connections on it this is the stepper card, make sure it is fully seated.