Ok, I’ve tried again and set all the mobo options in the installation guide to their correct settings except for
If your system has IO Serial Port, disable it
which I couldn’t find.
I don’t get the unauthorised firmware warning anymore but i get the initial black screen again.
I have a really weird situation.
High sierra worked fine. Updated clover, downloaded Mojave from App Store, installed and it restarted..
Now i just get a black screen. Even when i try to boot from a Carbon Copy clone or a USB rescue disk - it keeps showing the same black screen. Scratching my...