Question ASUS ROG Maximus Hero z790 Build unable to Boot; Hangs at Q-Code 60

[hypnocode]

Hello, just got my ASUS ROG Maximus Hero z790 board back from an RMA, where they purportedly fixed a resistor (it was hanging at code 7f). I got it back after almost a month, and put it back together only to have it hang on error code 60 before I can access the BIOS. It occasionally power cycles, but generally after doing that once or twice it comes back around to Q-Code 60, and super rarely will settle on 4f. In the manual thats "DXE Core started" which suggests it's Driver Execution Environment, I guess where it produces boot services, is failing.

The build pcpartpicker list can be found here: https://pcpartpicker.com/list/3vzPyg
And consists of the following components:

Intel Core i9-13900K 3 GHz 24-Core Processor
Asus ROG MAXIMUS Z790 HERO ATX LGA1700 Motherboard
G.Skill Trident Z5 RGB 32 GB (2 x 16 GB) DDR5-7200 CL34 Memory
2x Samsung 980 Pro 2 TB M.2-2280 PCIe 4.0 X4 NVME Solid State Drive
EVGA FTW2 GAMING iCX GeForce GTX 1070 Ti 8 GB Video Card
Fractal Design Define 7 XL ATX Full Tower Case
Corsair HX1200i 1200 W 80+ Platinum Certified Fully Modular ATX Power Supply

I opened another ticket with ASUS but they're taking a while to get back to me, so I'm hoping somebody out there in computer land will have some magical insight about this issue, or will see something I've completely overlooked. There's not a ton of similar issues I could find, at least none with a satisfying resolution, so I figured I'd be asking for posterity if nothing else. Thanks in advance!

 

[Lutfij]

Welcome to the forums, newcomer!


How are you cooling the processor?

I would breadboard the innards, using only the processor, one stick of ram on slot A2, without the discrete GPU or your storage drives, see if you can get POST. See if you can also reflash the BIOS using the BIOS FlashBack button on the rear of the motherboard;

View: https://youtu.be/ewg1aI0nhfE

Same principle even if the nomenclature on the board is different. After you've verified your BIOS was flashed to the latest version, clear the CMOS. You do so by disconnecting from the wall and display, then remove the CMOS battery, then press and hold the power button for 30secs then replace the battery after 30mins.

Did you inspect the CPU's socket for any bent or broken pins?

 

[hypnocode]

Okay, I've tried the bios update with it breadboarded. No dice.
I inspected the cpu slot, no obvious defects. Gave the cpu a very thorough cleaning with a q-tip and 91% Isopropyl Alcohol and reseated carefully. No change.