Still having a blackscreen with a new screen replacement

Hi everyone,

I replaced my screen almost a year ago and after the screen replacement, everything was working fine. But then, a month ago, my screen went also black. I replaced the screen with a new one, but I couldn't see anything on it EVEN if I can open the phone, feel his vibrations and unlock my phone with the fingerprint sensor.

So my question is : How can I fix this issue ? Which part I'd need to look at to repair my phone ?

If there's nothing I can do with your suggested procedure, how can I have access to my phone and save all my photos/videos/notes that I took to do a full backup of my data ? I tried to connect a USB-C to HDMI adapter on it with a keyboard and to connect it to my monitor but it didn't work.

Thank you so much community !