Apparently I have an issue with a display shield made/distributed by DIYmalls. I'm using the same mega 2560 and the same touch screen display but the DIYmalls shield only produces a white screen. I have another shield that look identical, except the board color is white, and the display works fine. The DIYmalls board is blue. When the program loads the screen looks to be changing but ends up white.
I sent the first shield back to Amazon but the replacement does the same thing.
Link to the shield - DIYmalls shield
There is no real technical details in your link, there is no way to compare to another similar part. That is why we do not like links from there. It appears the parts may look alike except for color but they probably are not. What was wrong with the original display? Does the pinout match? Are they both 5V units?
Looking into this more I found the 3.3v regulator on the shield was putting out 4.25v. There were a number of signals on the blue board that were significantly different than the white board. I was checking this without the display connected. The chips on the board can handle 5v so I don't know why the signals were that much different. When I say different I don't mean just a difference of .95 v.
Another thing I found is that the pins on the displays from DIYmalls have some sort of coating on them. I tried cleaning them with a flux cleaner and it didn't touch it. I had to scrape it off with an x-acto blade. Before the cleaning I was getting just a white screen or a messed up display.