I've got this display: http://www.electrokit.com/2-4-tft-lcd-t ... uino.49420
It's working on Standard UNO (5V) but just lit up on the Sparkfun Mega Pro (http://www.electrokit.com/mega-pro-5v-a ... belt.49198).
I've cut the 3,3V feed as it is connected to 5V on Sparkfun Mega Pro 5V. Yes, Works on Uno with the cut! Tested all relevant outputs on the Mega, Working !
Anyone got a clue?