The pixel has a very thin and fragile screen. It's very easy to damage the lcd without being able to see a visible crack. Also you could have knocked off components around the lcd connector. Or it could be a backlight issue. I would use a bright flashlight and shine it on the screen when you think it should be displaying and see if you can see anything. If you can then it's a backlight issue. If you have no backlight and no image then I would start looking at the board for damage. If you cant find any physical damage then I would get a new screen.