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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?

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  • What is powering the mega?
    – Majenko
    Commented Apr 30, 2016 at 12:10
  • an external adapter (9V,2A) Commented Apr 30, 2016 at 12:12

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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.

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  • So can I connect my lcd to the shield and connect the 5V pin to external power source and then connect the ground pin to the external source ground and make it common with the arduino ground? Commented Apr 29, 2016 at 0:03
  • Yep. That's right. As long as it is a regulated 5V power source.
    – Majenko
    Commented Apr 29, 2016 at 0:10
  • Sorry for the late reply (I was buying some components), I did try what you said, I connected my LCD to the shield and connected it to arduino through jumpers, except for the (3.3V, 5V, ground, Vin) pins wich happen to be the power pins on the shield, I connected them to external (5V 1.5A) usb adapter, I think that the LCD is stable now but I only get the backlight on...I can't see my code, it doesn't draw anything. Commented Apr 30, 2016 at 10:53
  • Is the ground connected to both the Arduino and the external power supply?
    – Majenko
    Commented Apr 30, 2016 at 11:03
  • I'm connecting Vin on the arduino board to 5V and whenever I take it off the LCD starts blinking, and I do connect the corresponding pin to Vin on the shield to 5v, I'm also connecting both the ground pins on the arduino and the corresponding pins to the on the shield to the ground of the 5V power source, the 3.3V corresponding pin on the shield is connected through a level shifter that I made of 10k and 20k resistors and connected them to the 5V adapter and finally the RST pin is connected to it's corresponding on the shield Commented Apr 30, 2016 at 11:08

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