arduino mega overheat when connected to TFT 7" and TFT shield I have bought a 7" LCD (TFT01-7) and a shield to make it work with arduino mega (http://www.elecfreaks.com/store/lcd-tft01-mega-shield-v10-p-214.html), but when I upload my code to the arduino and plug my LCD to the shield the arduino get overheated and the LCD lose power and I don't know why even when I power my arduino with external 9V 2A adapter, I even tried uploading an example from the library but it does the same, I used to work with the same code and the same shield but with 5" LCD ITDB50 and I didn't have this problem before, how can I fix this?
7" LCDs need a lot of current. They need it for the back light.

That current comes from the 5V pin.  That 5V pin is supplied by a linear regulator that has limited current capacity.  As you draw more current it gets hotter and hotter and eventually shuts down.

You will need to power your LCD screen with another external 5V source. The best solution may be a powerful (2A) phone charger (USB) which you then plug direct into the USB port of the board thus bypassing the weak regulator.