Limit switch locations and origin are not necessarily the same thing.
When you send a home command, the motors have to turn in the direction that will bump the end stop switches. The switches can be located at either the minimum or maximum of the X and Y axes, but the origin (coordinates 0,0,0) has to be at either the front left corner or the right rear corner of the machine. You have to make appropriate settings in the firmware and plug the endstop switches into the right connections on the controller board. There is a full explanation here: [
drmrehorst.blogspot.com]
Ultra MegaMax Dominator 3D printer: [
drmrehorst.blogspot.com]