SOLVED: Ugh - 4080S Issues - Black Screen after BIOS Splash, OS running.

[Narj]

All well and good, but maybe he's just a plonker

Happy to admit when I've been a complete idiot, in fact it's easy to do stupid things when you're flustered but the very weird behaviour here still has me stumped.

I'm not a guru but I've been building and swearing at systems since P2. I do suspect this motherboard has a lot of juice retention which is quite apparent when you disconnect power and have the track LED feature on. That might have been one factor

I just had a weird issue where having dual monitors attached on boot resulted in no video at all so I disconnected one, booted, reattached the second and it's fine over several reboots now. I think something is going on that will be resolved by a new base setup in all honesty. I get it, it's a Frankenstein's monster setup for modern standards but it is what it is for now

 

[JediFragger]

Dude we've all done it at some point inc me, we live and learn

 

[Narj]

Hmm compared initial BIOS settings and the only differences I saw with the exception of XMP profile related changes were:

- Intel Virtualisation Technology -> Disabled
- Vt-d -> Disabled
- SW Guard Extensions -> Software Controlled
- Above 4G Decoding -> Disabled

Just re-enabled Resizable Bar again as it's off by default, which then disabled CSM and enabled Above 4G Decoding. @Vimes good shout on CSM OFF being correct.

The machine still boots (hoped it would due to msinfo32 showing UEFI) and things still seem to be working so yeah... happy but confused.

I've re-enabled virtualisation as I need that for VMWare (don't need nesting right now so left VT-d off). Saved good BIOS settings to profile and USB

Every day is a school day, I learned quite a bit from this at least even if it's given me some more grey hairs.

Cheers again, all. Never give up!

EDIT: On reflection, I had dusted out the PC a few days before receiving the GPU in preparation. I wonder if the glitching and weirdness (or a loose connection) was kicked off by this. Weird how it didn't manifest until a while later after testing other GPUs fine though.