ROG STRIX Z790-E GAMING WIFI II -- boot failure (qcodes A2, 98)

[sfc]

Motherboard: ROG STRIX Z790-E GAMING WIFI II
Memory: CORSAIR - VENGEANCE RGB 32GB (2x16GB) 6000MHz DDR5 (single stick installed in A2 slot for now)
HD: Samsung 970 EVO Plus 1tb M.2
Graphics: PNY - NVIDIA GeForce RTX 4060 Ti 16GB GDDR6 PCIe Gen 4 x16 Graphics Card
Cooler: CORSAIR - iCUE H150i ELITE LCD XT
PSU: CORSAIR - RMx Series RM1000x 80 PLUS Gold

I've never been able to get this build to do anything other than throw an A2 or 98 Q-code no matter what I try: reflash the BIOS, clear the CMOS, strip the system down, etc. Am I missing something extremely obvious?

[sfc]

This is a brand new build.

[Vynra]

and what cpu are you using...?

[sfc]

Intel - Core i9-14900K

[Vynra]

And you were using the correct slots a2 and b2 (slots 2 and 4) ?

[sfc]

Yes (only slot A2 is populated at the moment)

[Silent_Scone]

Hi @sfc 

What happens if you try to use the iGPU instead?

[sfc]

Using the iGPU results in either an A2 error (first boot after BIOS flash) or 98 error (subsequent boots) and no display output, just as before.

[sfc]

I tried plugging an Aurga wireless KVM device into the iGPU and now...