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.

[Gatt]

Wow, and I thought to be the only one with this problem. I built my system with a brand new ASUS Rog Strix 790-E and Corsair Dominator 6200 (2x16GB). First try: error 55. Rechecked all, uninstalled and reinstalled everything. Error 55. Checked and re-checked the RAM sticks (I assemble my desktops since 10 years). Error 55. After a couple of days, just before RMAing the ASUS MB, I tried the 2x16GB sticks in slots A1 and B1 (!) and ... it posted! I went into the bios with F1 and made all the changes I needed. After that I put the sticks in A2 and B2 and everything is going well since then.

[Duncan91]

I just wanted to share an update, for all those interested. The motherboard was indeed the culprit, after swapping out to a replacement board all issues disappeared, thanks again to all those who offered suggestions.

[Hopper64]

I was afraid that might have been the problem since I also had a MZ790E do the same thing. My second board was fine. Glad you have it corrected!

[FireRx]

Geez guys,  Now I'm nervous. I haven't even tested my board yet, and I know the stopped making them, So if I have a problem I'll have to get a different board or go to a different manufacturer. I can't imagine ASUS having many boards for RMA left. 

[Hopper64]

Put it on a test bench or the top of the box and test it. Make sure it posts.

[Richard3125]

I think I have the same issue with both A1 and A2 ram slots. Before flashing the bios to the latest version, I didn't get any video at all. I have 4 memory sticks, but I'm currently working with 2. I thought it could be the power supply, but it works fine in my old PC 10900k. I don't know if I should change the motherboard. Since I live outside the U.S. I would have to wait a couple of weeks to get a new one, or purchase a pressure plate as suggested in other forums. But since I already made the mistake of buying a Gamdias chione p2-360r Changing it or upgrading it to an E version could be a viable solution. I would appreciate any advice. Can the ME firmware. Cause this issue?

ASUS ROG StrixZ790-F Gaming Wi-Fi / G.SKILL F5-6400J3239G16GA2-TZ5RK / 13900KF / 3070TI / Samsung 980 Pro / Samsung 970 evo plus / Corsair Serie RMX, RM1000x

[Silent_Scone]

hello,

looks like you’re combining the two kits, which is not recommended. Do you get QLED code 55 even after directly clearing the CMOS (optimised defaults)?

[Richard3125]

I get it if I use any of the A Channels. But if I only use the B channels I do not have any problem even if I enable the XHM or even AI optimized which without dual channel there is no point in using it. 

[Richard3125]

I meant XMP not XHM.  I forgot to add that the power supply is Corsair Serie RMX, RM1000x and the AIO Gamdias chione p2-360r

[Richard3125]

Which two kits are you referring to? All the memories have the same chipset, all of them are G.SKILL F5-6400J3239G16GA2-TZ5RK. Sorry, I am not the well versed in PC's.