BSOD iPhone 13 despite several restores/updates and repair. What to do?

Hi there!

A user has been having troubles with her iPhone 13 pretty much ever since she got it (May 2023).

We configured it at the IT office without any issues on arrival and just updated it to the latest iOS before handing it out.

After a few weeks she contacted us saying the screen was very dark all of a sudden (as if it automatically adjusted the brightness through a mixture of night shift and truetone but way more than what's possible in settings). She could barely make out anything but after a restart it appeared the problem had been solved.

Fast forward two weeks and the problem resurfaced. However this time the screen went completely black and a restart didn't help so she came by our office and dropped off the phone here.

I connected it to a PC and put it in recovery mode. The only time I could see anything at all was during the hard reset (the Apple logo showed up, although a bit yellow as if a 1000% night shift had been activated)

After that I applied another iOS update through iTunes. That solved the issue and it worked for about a month or so.

After getting the phone back and when a restore and update didn't work we sent it to a certified Apple partner but got the phone back within two weeks with a note that said "no aciton required" as they couldn't find any physical damage to the phone but yet another restore - update seemed to have fixed the issue.

The phone worked well for a few months after that but here he are, yet again.

Updating iOS and restoring the phone no longer work. It does however react when I press the side button+volume down (as a slight vibration) and it shows the Apple logo when I do a hard reset (volume up > volume down > hold the side button).

I've tried restoring+updating several times and I got different error codes and I've googled them all but they all refer to the same steps "update itunes, restart computer" etc. Nothing worked.

I finally managed to update it to iOS 17.4.1 thanks to a third party software but to no avail, the screen is still black even after restoring it. During the restore process the progress bar and the logo are visible but as soon as it's completed, the screen turns black again.

I'm running out of ideas to try seeing as I've pretty much tried everything.

The phone was bought by a swedish company so there's no "official" Apple-support seeing as it wasn't bought on Apple.com.

Here's two pictures of the screen (only time it's been working)