Question Diagnosing whether it's the CPU or mobo that's faulty ?

[yksi]

I am testing out a computer I was hoping to have just finished when I found that it will simply not POST when any more than 1 RAM slot is filled. I did the usual RAM diagnostics, and found from Googling that this exact issue actually may be caused by the CPU/mobo socketing. Apparently overtightening coolers can damage the CPU-mobo connection and cause this exact issue where more than 1 RAM slot being filled causes POST failure.

That got me worried, as I did do something pretty stupid when installing. It’s a liquid-cooled PC, and I started with a defective CPU waterblock, whose screws were too short. I don’t know why, but I took this as a challenge to force it to screw in correctly. I never succeeded (and ended up successfully RMA’ing the block) - and I was definitely squeezing the block and backplate together WAY too hard, for about 10-15 minutes’ worth of time.

Thus I’m pretty confident I am experiencing issues caused by overtightening blocks. But, with exactly 1 stick of RAM in slot 4, the computer runs perfectly fine.

I’m now wondering the best way to figure out whether I destroyed something in the motherboard vs. something in the CPU. Are there any sort of tests I could do to isolate which is causing the problem?

My planned first step was to check the CPU for bent pins. Is there anything else I need to rule out the CPU being the broken component?

I suppose my tl;dr is: “Which is most likely to break from overtightening a CPU cooler and cause failure to POST only with more than 1 RAM stick: the mobo, the CPU, or (please no!!) both?”

 

[Lutfij]

If this is a board with an LGA socket, then yes the unnecessary pressure can and will bend the contacts on the underside of the processor and cause contact issues. There are instances where the PCB traces were also damaged(as is the case with JayzTwoCents, where he drilled holes into his ASRock X99 platform and then realized he also took out PCB traces that ran around the screw holes) when someone decided to try and have screws mate with a backplate.

For the sake of relevance, can you please include the specs to your system that you're troubleshooting, like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
BIOS version for your motherboard? Which slots are you working with the sticks of ram on the motherboard?

 

[yksi]

Sure.

CPU: Ryzen 9 5900X
Motherboard: ASUS TUF GAMING X570-PRO WIFI II
RAM: Corsair Vengeance RGB Pro 32GB (2x16GB) DDR4 3600 (PC4-28800) C18
SSD: Samsung SSD 860 EVO 1TB
GPU: AMD Radeon RX 5700 XT
PSU: EVGA Supernova 750 P2
Chassis: Phanteks Enthoo Pro M
OS: Windows 10
BIOS Version: 4204

I currently have 1 RAM stick working in DIMM_A2, the slot farthest from the CPU. I have not tried other slots as I believe you always need to use A2 when you have 1 stick, right?

 

[yksi]

I did a little bit better testing today with more alternate RAM combinations.

I found that the computer simply will not POST whenever ANY B RAM slot is filled. DIMM_B1 and DIMM_B2 having anything in them causes failure - whereas I am currently running fine with A1 and A2 both filled. However, it does not seem to be a "dual-channel vs. single-channel issue" - as I went down the list inserting only a single RAM stick and trying to boot. B1 and B2 both failed when I tried this, whereas A2 again booted fine and so did A1. It seems to me more that the B slots themselves simply do not work, rather than "the mobo's dual channel is faulty." Would you agree? Or is it possible for a CPU/mobo issue to be causing the B slots to simply never work?