Maximus Z790 Extreme Persistent Qcode 55 "Detect Memory" issue

[Duncan91]

Starting a post for some help with a detect memory issue I can't seem to solve.

Problem: Can't get past POST, persistently get Qcode 28, 54 and then hang on 55. Using latest (0904) Bios while writing this. Have swapped out RAM from my original kit (F5-6000J3040G32GX2-RS5K) to (F5-6800J3446F48GX2-TZ5RK) as I initally thought it was faulty after remounting everything and trying all slots whilst isolating ram sticks. I have checked all pins and PCB tracks (specifically the ones to the right of the CPU around the mounting holes. No RAM slots provide a successful boot whether I use 1 or 2 sticks. I have tried rolling back BIOS and cycled between chips 1 and 2. I have tried safe boot, battery out, 60s CMOS hold reset, loosening CPU cooler mount screws, loosening Backplate screws and gradual tightening again whilst periodically clearing CMOS and booting.

RAM is always checked and checked again for a firm and correct seating.

Setup;
CPU: 13900K
MB: Maximus Z790 Extreme (0904)
RAM: F5-6800J3446F48GX2-TZ5RK
GPU: Strix 4090
PSU: Be Quiet Dark Power Pro 1200
Cooling: CPU block Heatkiller IV with LGA1700 Heavy Backplate and washer mod (0.8mm), Heatkiller V Pro 4090 Strix

I'm running out of ideas. I appreciate the help, thank you.

[Duncan91]

Can I just confirm that the Intel ME firmware, advised by ASUS to be installed prior to a BIOS update is installed in the OS? As my issue prevents me to advance past POST I'm wondering how I can in fact load this Management Engine Firmware.

[Hopper64]

You are not going to know until it posts in the bios. I doubt the latest FW is installed currently, but I don't think that's the problem. I guess it could be since you flashed 0904 without knowing what FW version is present. I just think it unlikely.  Typically it's recommended to install the latest management engine in the OS first, then the FW, then the bios. You haven't been able to get that far yet. I know the feeling. Had the same issue.

[Duncan91]

I flashed because I hoped that a newer BIOS would support my high density kit F5-6800J3446F48GX2-TZ5RK after originally having no post with F5-6000J3040G32GX2-RS5K and believing it was the culprit. Would you suggest loading the factory BIOS, if so where can i find it online?

[Hopper64]

You could try that. It should be on the download site for the board.

[Hopper64]

Looks like 0502 is on the site.

https://rog.asus.com/motherboards/rog-maximus/rog-maximus-z790-extreme-model/helpdesk_bios/

It may have shipped with version 08xx though. Hard to know.

[Duncan91]

Hi Hopper, I've already tried 0502. I thought perhaps there was a version prior this.

[Hopper64]

I don't know if there was, but if you tried that then you have exhausted that possibility. I don't think 0502 required a FW update.

[Duncan91]

Just to clarify guys, I’m reading quite a lot about channels A1 & B1 falling over due to contact pressure or tracer track damage. However if all 4 slots, both channels fail to be recognised and the RAM kit is ruled out as not being faulty would that indicate a faulty memory controller? POST codes for CPU pass but RAM codes fail (Qcode 55)? 

There is NO damage on the motherboard, it’s brand new and it’s been tested in factory config, with the washer mod and the contact plate mod. All yield no success.

[Silent_Scone]

Hello,

Contact issues will typically manifest either intermittently or for a particular slot. If no success after attempting to remount or even with a third party contact frame it would suggest the fault is either with the CPU or motherboard.

[Duncan91]

Cheers Silent_Scone, as I said, I look forward to swap out the CPU on order to fix it and or rule it out and then start with the motherboard RMA. I will update with my findings