Screen replacement won’t turn back on

I would try doing a hard reboot first. Hold down the volume button and power button until you see the Apple logo. If that doesnt work, try plugging it into your PC or Mac to see if it’s recognized. Lastly try reseating all connections. If none of these work, try another screen to rule out the replacement part going bad. You could have a short on VDD main or some other short that could be causing the phone to not take a charge. Hopefully one of the above steps fixes the issue, because a short will require microsoldering repair.

disconnect battery plug in screen and connect to charge. (try just the screen without the front camera)

You should get an apple logo after 10 seconds or so

If you don’t, check your charge port is seated correctly

Sounds like your phone is fake charging