I like my little EZ servo motor. Would be highly disappointed if it went away.

The first thing I'd try is remove the power and unhook and re-connect all cables from the EZ-Guide to the EZ-Steer. Could just be a loose connection. On the other hand, when I had the controller box open, I seem to remember a fuse on the circuit board. Might warrant a quick trip to the folks at AgExpress, as merely replacing a fuse seldom solves the underlying cause for the blown fuse.