Question 2 of 4 DIMM slots not working?

[ArmoredRhino187]

Hi all

I recently built a new gaming system, everything seemed to be okay until when I got to the POST

From what I could see it seems that 2 of the 4 DIMM slots on my motherboard would not work in the sense that the DRAM Warning light would stay on when there were any modules in these two slots. From left to right you have slots b1, b2, a1 and a2. b1 and b2 are the slots that seem to have this problem. After testing each of the 4 RAM sticks in A1 and A2 i was able to confirm that the RAM was functional and dectable by the system via BIOS. I updated the BIOS to the latest non-beta version for stability to no avail. After inspecting the CPU pins I confirmed that there was no noticable bending or forced installation as the CPU essentially sunk into the holes on the AM4 socket very easily with little to no force required. The BIOS detected the CPU and after installing windows and inspecting the components the CPU was functioning normally clocking around 3.4 GHZ at the time. After this I checked out the AIO and for any loose cables and I could see nothing amiss. There are two things that I thought I should note as they may or may not have a weight on the reason for this issue.

1. The CMOS settings are out of date even after updating. I removed the coin battery for 10 minutes and reinstalled it which did nothing
2. When booting the PC, the system fans are connected via a corsair Commander module and for this reason the CPU_Fan 1 header on the motherboard is vacant. The system will warn me that a fan is not connected in that header but will continue to boot

I have the ability to send this motherboard back for an RMA as I am quite certain its is the board that is faulty. There were no obstructions or dust in the DIMM slots as the board was new but I airblasted it afterwards to be on the safeside as well

If you have any other suggestions please feel free to let me know, many thanks
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SYSTEM SPECS

MOTHERBOARD : ROG STRIX B550-F GAMING WIFI II
CPU : AMD RYZEN 9 5900X
CPU COOLER : CORSAIR H150I RGB ELITE CAPELLIX 360MM
FANS : 3X CORSAIR 120MM RGB along with AIO connected to CARSAIR COMMANDER PRO MODULE
GPU : EVGA RTX 3090 FTW3 ULTRA
RAM : 2X CORSAIR VENGENCE LPX 3600MHZ 16GB (2 X 8GB)
STORAGE : 2X SATA SDD
PSU : CORSAIR RM1000X THERMALLY CONTROLLED MODULAR POWER SUPPLY
CHASSIS : CORSAIR 4000D AIRFLOW

 

[SkyNetRising]

RAM : 2X CORSAIR VENGENCE LPX 3600MHZ 16GB (2 X 8GB)

Install ram modules in slots A2 and B2.
Install modules from the same kit. Avoid mixing kits.

 

[ArmoredRhino187]

Install ram modules in slots A2 and B2.
Install modules from the same kit. Avoid mixing kits.

Attempted this as well as a1 and b1 for dual channeling. It didnt work. For some reason if there is module present in either b1 or b2 at any given time the computer will refuse to POST and will just show the DRAM warning light.
And yes I seperated and tested each kit so as to not mix them which still did not work. If it was A2 and B2, B2 would have an issue but A2 would be fine (tested this by first using both, then a2 only, then b2 only. and the problem seems to lie with b2 in this case) And the same for A1 and B1.

 

[kerberos_20]

ram controller is on cpu, b1 and b2 both not working would mean that your cpu has borked second memory controller
id start with cpu rma

 

[SkyNetRising]

Damaged cpu actually is quite unusual (and unlikely). Unless it was used for heavy overclocking before.

More likely is damage to motherboard during installation of cpu cooler.

 

[ArmoredRhino187]

Damaged cpu actually is quite unusual (and unlikely). Unless it was used for heavy overclocking before.

More likely is damage to motherboard during installation of cpu cooler.

If it was the CPU then it would have been an issue during its manufacture as im sure I took the necessary steps to making sure the pins were aligned properly and when it came to installing they sat in perfectly. Ive tested and removed the CPU to inspect for any wear or damage to the pins but honestly nothing. The BIOS seems to see everything fine and even Windows was able to detect 4 available DIMM slots for RAM.

Would it have anything to do with the AIO pump that is being used or would that not be relevant in this case? Otherwise the installation was pretty smooth, didnt hit anything, it pretty much sat on perfectly and I made sure not to over tighten the cooler