ProArt Z790-CREATOR boards wont post if RAM is in slots A1 or A2

[shadedurza]

I'm trying to understand why the ProArt Z790 refuses to POST with ram in slots A1 or A2. It's very clear from the manual that the "recommended memory configuration" for 2 sticks is in slots A2 and B2 however I am now on my second brand new board that won't post with RAM in that configuration.

If I POST the board with RAM in B1 and/or B2 slots I am able to get in and change the xmp settings. If the board is left with XMP off, powered off, RAM installed in A2 and B2, then powered on, no POST. Only yellow DRAM light forever.
If I do the same thing but turn XMP on, I get no POST however the yellow DRAM light sometimes changes to red and then switches back to yellow periodically. I believe this is the board attempting to find a RAM speed it can POST with and/or attempting to POST in safe mode.

Troubleshooting:
Issue occurs with BIOS version 2302 and 2504.
I am able to get both boards to POST with RAM in slots B1, B2, and B1 + B2.
After getting either board to post with RAM in the wrong slots I have tried turning XMP on or off. No difference.
I've tried with multiple RAM kits including the G.Skill 64GB (2x32GB) F5-6000J3040G32GX2-TZ5RK
which IS listed as a supported kit as well as a Corsair 64GB (2x32GB) kit which isn't listed as supported. Same issue with either kit.
Because I've read that contact frames used by the kind of CPU cooler I have can bend the motherboard, as a troubleshooting step I've tried uninstalling the Liquid CPU cooler and replacing with just a simple stock intel cooler that used to come with older CPUs. No difference.

Please let me know what I'm doing wrong or if there are any troubleshooting steps I've missed.
Thanks

Specs:
Motherboard:
Asus ProArt Z790-CREATOR WIFI ATX LGA1700
Processor:
Intel Core i9-13900K 3 GHz 24-Core
CPU cooler:
Arctic Cooling Liquid Freezer III 240mm
or
Old stock intel cooler
Memory:
G.Skill Trident Z5 RGB Series 64GB (2 x 32GB) DDR5-6000
or
Corsair Vengeance RGB 64GB DDR5-6000 PC5-48000 CL30

[shadedurza]

After further troubleshooting I have confirmed that both boards POST and boot as expected, with either kit of RAM, while using a 14th gen processor (Intel Core i9-14900KS)

Is this a compatibility issue or could there actually be something wrong with the CPU? I've inspected it very closely and there doesn't appear to be any sign of damage. Are there any tests I can run to verify something is wrong with it?

[achugh · Accepted solution]

Hi @shadedurza , typically the A1, A2 slots not working is a sign of either the CPU or the socket getting damaged. If you replace the CPU and then everything works points to CPU being damaged or being the issue.

[shadedurza]

A damaged CPU you say? If only there were some color the light on the motherboard could have changed to in order to indicate that. Could have sped the troubleshooting process right along. Oh well. 🙄