I agree withVator gator, I have had similar troubles with one board dragging down communication for all.,does the elevator level back into the floor after you run it away on insp,then put it back on auto..( prob not) will the door open or close when using test buttons on the door board? Unplug the door board and selector board then try clc communication. Clc is the heart of the system ,if this one will not communicate this is a good place to start when replacing boards