Replaced Battery now black screen won't connect to laptop - save data?

Please help, my little brother replaced my dad’s iphone SE (1st Gen) battery and now it won’t show on laptops when connected and it only displays a black screen. If the phone is not fixable, it’s not the end of the world but he really would like to retrieve his data, he has tons of pictures on it he didnt back up.

From what I understand they went to a small repair shop and the guy performed a couple of tests to see if the phone was dead. Apparently the battery is working and charging and the screen should be working too, but it was outside his filed of expertise. I tried a couple of manipulations to see if booting could be done. I got a slight vibration but then nothing. Didn’t manage to get to vibrate a second time.

Any ideas how to either fix the phone or retrieve the data ?