Axis not homing help!

Hello,
This is my first build so I am new,, I am building a Rostock with a ramps 1.4 I am using mechanical end stops. Whenever I use my LCD controller and hit auto home, all three axis go up heading to the end stops but if the x and the z touch first then the y will not go all the way up to the switch. Same thing if the z and the y touch, the x will not go all the way up. Can anyone help me with this?

Thank you

Edited 2 time(s). Last edit at 02/15/2015 12:04PM by Smedek.