UTFT+ITDB02-5.0 (SSD1963)+adruino mega 2560 white screen

Just an overview....it appears you are on the right board, you are using the right library, and you have a good display. I do have one concern about the shield. Have you found others using this combination? The iteads use a shield with ICs to reduce voltage while the elecfreaks use resistors. Shouldn't be an issue but maybe something to look at.