PC was randomly rebooting, took everything apart to dust out and reseat everything and found the culprit. I'm glad I spotted it before it properly melted / caused a fire…
I used the included 4x 8pin to 12VHPWR adaptor specifically to isolate this potential issue from my PSU and I'm glad I did, put an old GPU in and everything is fine again so I've started the RMA process.
I have a wireview pro II on order, so naturally this would happen just before that arrives…
Originally posted to the nvidia subreddit but it was removed, same with a cross post to MSI_Gaming, I can't imagine why. Maddening, I'm trying to post for other users in the same boat.
If you're a poor soul coming from google, the windows event viewer was showing:
“`
The computer has rebooted from a bugcheck. The bugcheck was: 0x00000116 (0xffffe183c6516010, 0xfffff8058f53f140, 0xffffffffc000009a, 0x0000000000000004). A dump was saved in: C:\WINDOWS\Minidump\011726-25109-01.dmp. Report Id: 53b6b18f-37dd-47d7-a174-d5b2995732fb.
“`
And looking in the dump file with `WinDbg` showed `nvlddmkm.sys`, an nvidia driver component, was the cause so I was already worried it was GPU related.