Display does not come on after drop

Is the screen cracked? It’s likely that it is given that it was dropped from a rooftop. When you press the power button and start touching the screen is there any vibration feedback?

If your screen is black then the LCD display is likely broken or possibly came disconnected. You could try opening up the phone to see whether it came disconnected or not. My money is on the LCD being broken. There’s not much you can do besides buy a new LCD display for the phone.

Assuming you need to buy a new LCD you want to also make sure that you’re getting some sort of vibration feedback when touching the screen. If nothing happens then it’s also very possible that the phone’s touch digitizer is broken. You’ll want to replace that too. Usually these replacements come in pairs which makes them very easy to install.

Here’s a combo pack that might work for you if you need it (LCD display and touch digitizer) https://www.ebay.com/itm/LCD-Display-Tou...