Seeedstudio tft v2.0 & Plotter consumption's problems

Hi friends, first excuse me for my english, i've used Google Translator I'm doing a project for a plotter. I decided to handle it using an Arduino Mega 2560 and the touch screen, tft Seeedstudio v2.0, I have everything set with its interface and all arrows Xd. It works perfectly, loading the background image and detects exactly where you are pressing. Consuming Seeedstudio v2.0 tft is 250mA

The problem comes when, for a given arrow, like for example a LED light (to simulate an engine, or an outing to a L293D), for example. This LED is not lit, just, I measured with a multimeter and does not exceed the 1.58 V on average. However if I connect this led resistance through to the output of 5 V looks like a champion.

I guess it's for the consumption of the display, that all power is carried Arduino. Before writing this, I have read many post and I find your solution. My source current increases, which Arduino can only occur between all outputs 250 mA .... The maximum current that can give pin is 40 mA, but that does not mean that taking 54 E / S to give a total of 2,160 A, right?, If so it would increase my power to not exceed 2.1 A.

Please if anyone can help me with my question I'd appreciate it.

Thanks in advance.

please post schematics and code, that will tell us the details