LCD not turning on with RUMBA board

I have a RUMBA board, and I'm trying to connect a Full Graphic Smart LCD Controller from ReprapDiscount to my board. The LCD never turns on. Currently I've connected EXP1 from the LCD to EXP1 on the board, and the same with EXP2, with the red wire on the ribbon cable, closest to the black triangle on the RUMBA PCB. I've loaded the firmware, hotend and heatbed are heating up, motors are working fine. The only problem is, the LCD never turns on? What could be wrong? Should I try to flip the connectors for the LCD, can I damage something?

Found the problem with the LCD. Firstly I had to swap EXP1 and EXP2. Secondly, the potentiometer is a bit funny, the range at which the LCD display is visible is very narrow, so managed to get the contrast just right.