I would suspect wiring misconnection on your RAMBo board; I saw something on that subject on another forum. While the manual doesn't mention it other than the second picture off section 8.17, the LCD cables that go into the RAMBo board could go both ways, but only should be going one way. The pictures in the manual do show what color goes where, they just don't warn you to check for it other than that one easily missed picture. This is confusing in the manual as they say the cable with one stripe goes here, the one with two goes here... well, they mean 1 black stripe/2 black stripes. Both cables have one red stripe also, both of which need to be facing the 6 look-alike connectors that the endstops and PINDA probe go into.