When homing all the axes the Z and X axes start to home simultaneously. The Y axes waits. When the Z and X axes reach the home position the Y axes starts to home. All three axes have homing switches that are active low. I have used a logic probe to check the state of the homing switches and they are correct. (Pins 10, 11 and 12 )
It is my understanding that all three axes must home simultaneously. I have check all the software settings and can not work out why the Y axes waits for the Z and X axes before homing.