I recently purchased a Sainsmart 5" TFT display here.
I received it yesterday, along with its shield, and hooked it up to my Sainsmart Mega 2560. Had it working in just a few minutes with the UTFT library, everything looked good.
I proceeded to wire my Adafruit Ultimate GPS module to the board as well so that I could log some GPS data and display it to the TFT screen. I found that getting a GPS signal was considerably harder with the TFT screen connected to the same Arduino board, instead of receiving useful GPS data after 10-20 seconds, it would take ~10 minutes before getting a time and date stamp from a satellite. (This is in contrast to getting a full fix usually within one minute while the TFT display is not connected to the same board.) This difficulty did not change with an external power source.
Since it was taking so long to get any data, and had yet to get a GPS fix, I decided to leave it on overnight and log if/when it did get a fix and display that information to the TFT screen. I left the only power source to the Arduino as the USB cable from the computer. I woke up this morning and came to my computer to check the screen and it was completely black, the Arduino also being unresponsive. I unplugged everything and attempted to power on the screen with a mini-USB power supply to no avail. The Arduino is not damaged and works fine. The GPS module is not damaged and works fine as well.
If the screen is connected to an Arduino, the Arduino will not power on. This leads me to believe that something in the screen is shorted. I also tested the screen on a second Adruino Mega 2560 with the same results.
Thoughts? I’m at a loss. I guess I’ll have to call Sainsmart to try to get a replacement?
EDIT: I should also mention that the screen is completely black with no signs of powering on. I can get the red power LED on the bottom to come on if I supply Vin power to the Arduino instead of just the 5V from the USB cable.