Chosen Solution

So I changed the screen. Prior to this the phone was working. Now at startup, the logo is shown as usual for a few seconds. Then the logo turns grey and I get codes from the top of the screen. Nothing happens after this. What should I do?

Hello disconnect the frint camera cable and turn on again see does that fix it.. Usually a faulty camera flex causes this fault

There is three cables connecting the screen to the motherboard. Try disconnecting them, then reconnect them. Did this work?