Xiaomi MI 11 Lite screen problem

Hello, I have a problem with my Xiaomi Mi 11 Lite display. When I turn it on the screen flashes with white lines. I have tried replacing the screen twice as well as the flex connector but the same thing was happening. When I turn the phone onI can tell that, aside from the broken screen, that it works fine indicated by sound (hearing the startup sound, tap sounds, notifications ect.) I checked the fpc connector on the mainboard and it seems fine. Would appreciate any help.