Post code C5 on the Asus Crosshair X670E Hero motherboard

[OmLed]

Good day. This is the situation: an Asus Crosshair x670e Hero motherboard was purchased for an AMD Ryzen 7950X processor. As a result, during the assembly of the PC, a post code C5 problem with the RAM was detected (the RAM is compatible with the platform, listed on the Asus website), which is why the PC does not start, but if you insert 1 die into the second RAM slot, the system starts and loads into Bios, but if you install 2 memory dies yes, then the problem described above appears.

[OmLed]

I took the motherboard to the service center for warranty service, but can anyone tell me what the problem is? Can the processor be guilty of this (its memory controller)?

[OmLed]

Could there be a problem in Bios?

[avinashga23]

Try disabling the EXPO and load optimized defaults in BIOS and then it will work with lower RAM clock speeds.
Try incrementally increasing (200 MHz at time) the memory frequency and find out the maximum stable memory frequency which is possible.

I was having the same issues with my GSkill Trident Z5 32GB * 4 = 128GB RAM when expo enabled.
After disabling expo and playing with memory frequency the maximum clock speed i got working is 4000 MHz.

Also there is a new BIOS update 1516 (Beta) with AGESA 1.0.0.7b upgrade which is claiming to fix the Expo issue, you can try the same and if you can let me know how it goes, i can also try with my RIG

Below is my system configuration :-

Processor:- AMD Ryzen 7950X3d
Motherboard:- Rog Crosshair Hero X670E  

Memory:- GSkill Trident Z5 6000MHz (30-40-40-96)
GPU:- Rog Strix 4090 OC @ 24 GB

Chassis:- ROG Hyperion GR701

Power Supply:- Rog Thor 1200W P2

CPU Cooler:- Rog Ryujin III 360

[OmLed]

I took my board to the service department, and we'll see what answer they give about the motherboard, because I think that the processor still works (because the post codes go) and that the RAM also works in the only second slot on to pay I am not completely sure that it is the Bios that is to blame, because I updated it using the Bios Flashback button.

[Jiaszzz_ROG]

Hello, @OmLed 

Generally, we would prioritize recommending that you refer to the following FAQs, check the memory slot configurations as suggested in the user manual, update the BIOS, clear the CMOS,or perform minimal hardware testing to isolate the problem.
[Motherboard] Troubleshooting - No Power/No Boot/No Display
[Motherboard] ASUS motherboard troubleshooting via Q-LED indicators
[Motherboard] Common Q-CODE(Error CODE) and Troubleshooting
However, since you have already sent the device for repair, we advise you to coordinate with the repair center to obtain detailed inspection updates.

Thank you.

Hello, @avinashga23 

To avoid any confusion, I have updated the response in the thread you posted. 

Thank you.

[OmLed]

Most likely, the legs of the processor socket were damaged during transportation/handover, or in the service center itself. The warranty repair was refused and even the paid one!!! I note that when the product was delivered to the store, it was written in the service certificate that there were no questions (damages) regarding the appearance and quality of the product. That is, the product was damaged in the store/at the service?! Now I will think twice when buying a product from Asus! Support is simply zero!!!

[Jiaszzz_ROG]

Hello, @OmLed 

May I ask if you sent your motherboard to the ASUS official repair center?
Have you now completed the repair process? 
If the repair has been completed, is everything functioning normally with it at the moment?

Thank you.

[OmLed]

In my assembly, the C5 code was due to a bent leg in the processor socket. It is also interesting that the specification states that the system will start only in the case of 1 module inserted in A1, 2 modules and 4 RAM modules. Interestingly, the system will not start with 3 modules.

[djvagnetti]

I HAVE A 4-16-5600 CONFIGURATION WHICH IS IN THE "TESTED" QVL  WITH A RYZEN 7950X3D. THE SYSTEM BOOTED FINE WITH THE DEFAULT CONFIGURATION WHICH GAVE ME A 3600 MHZ SPEED. I FLASHED THE BIOS TO THE LATEST 1516 AND APPLIED ONLY THE ASUS-RECOMMENDED EXPO SETTINGS AND I AM GETTING THE DREADED C5 ERROR. I TRY TO CLEAR CMOS, RESTART THE BIOS, AND DIFFERENT DIE  CONFIGURATIONS AND IT WILL NOT EVEN POST. I SPENT ALMOST $7,000 FOR A CRAPPY SYSTEM AND THE MOTHERBOARD JUST WILL NOT POST. LET'S SEE IF WARRANTY DOES SOMETHING BECAUSE IF NOT I WILL NOT REST UNTIL I AM TIRED OF BLOGGING, VLOGGING, AND PODCASTING ABOUT THIS RIPOFF!