Unfortunately neither disassembling nor a display port cable solved the problem 😕
I really think the card is broken. I noticed that I not only get a black screen when installing the driver but also the whole system freezes because I can't activate/deactivate num lock anymore for example once the screen is black.
To verify that it is hardware I would suggest you try loading a much older driver as I have seen lots of complaints similar and reports of ultra wide resolution issues. Maybe try 17.10.1 one of the older driver last know to be rock solid before a lot of the newest features were added to the drivers that fubar'd things for so many.
I've installed the 17.10.1 driver but the problem persists: crash with black screen 😕
I will borrow another card to verify that this is the problem.