Screen doesn‘t work after replacement

So i dropped my iPhone 8 and when it fell the display didn‘t function anymore altough the glass was intact. At first when I used the power button the screen did turn on and off (just like a tv without any channel on; you could see that it has elecricity but it was a black screen tho). After i made a hard shut down (pressing the keys) the screen was just plain black (no electricity) but everything functioned (except you know… the screen). I thought maybe the LCD or touch might be broken and bought a replacement screen. Long story short end, nothing changed after replacing the screen