I dropped my phone and the entire screen went black.

Hi Rami,

While there is a small possibility the display connector has gotten disconnected as a result of the drop, it's far more likely that the fall has exacerbated the existing screen damage and put the final nails in the screen's coffin.

If it was my phone, the first thing I'd do would be to follow the screen replacement guide up through Step 5 where it shows how to disconnect the LCD connector. Unplug the connector, clean both sides with 90% or higher concentration isopropyl alcohol then reconnect it. Reassemble the phone and see if that's made any difference.

Motorola Moto E4 Screen (No Fingerprint Sensor) Replacement - iFixit Repair Guide

If, as I suspect, it still doesn't show a picture, then you'll need to source a replacement screen and follow the guide the rest of the way through to replace the LCD. Don't forget to purchase precut screen and rear case adhesive sheets so it'll stay together when you reassemble it. Just as a tip; I usually buy a couple when I need them; they're quite inexpensive and unfortunately all too easy to mess up, so having extras on hand saves you from having to wait while you reorder if you do get them tangled up and unusable.

If your phone is the model with the fingerprint sensor let us know and we'll see if we can locate the correct guide for that phone since the guide I pointed to specifically says not to use it if your phone has the fingerprint sensor.

Good luck; let us know how it goes!