Hi enb141, sorry to hear that. So your memory is OK during tests? Have you tried all of the following? (easy things first - your BIOS settings may not be exactly the same):
1) Unplug everything you can (I know you've tried this) also try another keyboard and mouse if you have alternatives
2) Disable PCI Express Native Power Mgt in BIOS (advanced tab, platform misc configuration)
3) Disable Native ASPM (Active State Power Management) (advanced tab, platform misc configuration)
4) Make sure that maximum power savings in Link State Power Management in Windows (Edit Power Plan/ Advanced settings/ PCI Express/ Link State Power Management) are NOT enabled, or only go for moderate power savings
5) Try running Command prompt as admin and type: sfc /scannow
6) Then also try as admin: DISM.exe /Online /Cleanup-image /Restorehealth
7) Turn XMP off and/or run the memory at lower speed, try different RAM sticks
😎 Try an earlier BIOS
9) Reinstall Windows (save all of your files first!), make sure that you have all of you motherboard drivers re-installed
10) Reseat the CPU
I hope one of the above helps or that somebody else can suggest some other things to try.
Z690 Hero, BIOS 2802, MEI 2336.5.2.0, ME Firmware 16.1.30.2307, 7000X Case, RM1000x PSU, i9 12900K, ASUS TUF OC 3090TI, 2 x 16GB Corsair RAM @ 5200MHz, Windows 11 Pro 23H2, Corsair H150i Elite AIO, 4x Corsair RGB fans, 3x M.2 NVME drives, 2x SATA SSDs, 2x SATA HDs.