Perfectly working system now has boot issues after current spike?

Hi Guys,

As the title says, I had a perfectly good running system with Big Sur, i5 6600k (skylake) running integrated and outputting fine over hdmi to a UHD monitor.

It would then appear a voltage spike occurred frying not only the psu but the display and HDMI port. When trying to boot the system off display port instead, the apple logo and bar comes up but then the screen goes black outputting no signal once the bar gets to the left hand side of the apple logo.

I have tried booting in verbose from a USB with the same config on it and these are pictures of the last thing I could see;

https://imgur.com/a/5mDY5l5

And the parts list;

https://uk.pcpartpicker.com/list/qMhZhy

Any help would be great, I remember patching a fair amount of stuff when getting the UHD output to work but can’t for the life of me figure out how I did it in case that is the issue.

Thanks!