[SOLVED] New PC, mystery problem? I am running out of options.

[Theriak25]

Hi guys,

I bought a brand new pc, but I am still having problem which I am unable to solve. And I am running out of options .

Relevant specs:

AMD Ryzen 5800x
Gigabyte B550 AORUS elite v2
2x16Gb HyperX Predator DDR4 32GB (Kit 2x16GB) 3600MHz CL17
Gigabyte Nvidia RTX 3070 Eagle 8Gb OC
Be Quiet! Dark Rock4 cooler
PSU Seasonic 750w

The problem is related to DDR's or Mobo (I guess). Computer does not boot with both modules, only with one (most of the time, more to this later). Both modules are correctly placed in slots A2 and B2 (recommended by MOBO manual). It only shows the memory in A2 slot, never in B2. I moved a fan and placed the DDR's to A1/B1 slots. Same problem, B1 slot didnt show the memory, which surprised me, i was just thinking its the one faulty B2 slot and that will be all. Well I tried every single scenario, so i tested every slot alone, with one module first and second module after. Everything worked expect the B2 slot. I tried different DDR's from my older PC, same results.

What confuses me the most is the fact that A1/B1 configuration didnt work, however B1 alone works. A2/B2 configuration didnt work either, but then again B2 alone didnt work so it makes sense.

I took the pc to the shop where i bought it (one hour ride by a car). To my surprise, everything worked there as intended. We were not able to replicate the problem (we tried it for like 40 times) Everything worked flawlessly! Shop is trustworthy, no scam there, I was there all the time. Guess what...I came home, turned pc on and problem was there again. What a bad Mojo.

To make things even more complicated - very few times (like 1 from 40 times), it booted with both A2/B2 slots working. When did it happen? It was when pc was lying on a side. When I tried to move the case, even after the smallest movement, screen went black, it rebooted and came back with only one active A2 slot again. With only one slot booted, it is not sensitive to movement at all. DDR's were correctly placed within the slots and were secured all the time.

What I tried?

• Different memories (2x16Gb HyperX Predator, 2x8Gb HyperX Savage)
• Loose the cooler, tried boot it a few times with less pressure from cooler to CPU, then tightened it again (I saw it here in other thread, did nothing for me)
• Different Cables
• Changed/Turned on and off XMP profiles
• Checked my Mobo has most recent BIOS
• Loaded BIOS to default, several times
• Visually checked mobo, checked all connections there manually
• Tried different sockets and plugs, different rooms withing my flat
• Praying
• Cursing

What I cant do?

- Check possible bent pins on CPU


I am out of options I am aware of. I cant do much more with the PC myself, I can do only basic things alone. However if I cant replicate the problem in the store, there is nothing they can do for me. Other than that PC works almost perfectly, only when I connect my AOC 24G2 to the GPU with Display port, it is 50:50 it will work. No problem with HDMI tho.

I am stucked now.

Thank you very, very much for a help. And sorry for my English.

 

[alceryes]

There is a know, weird issue that affects memory channels when the CPU cooler is too tight. Loosen it SLIGHTLY (or remove and reattach).

It should always be tight enough so that you cannot move it at all if you push it from the sides.

 

[cryoburner]

That's unfortunate because the memory controller is in the CPU and if you have bent pins that would be the cause of your issue.

That wouldn't really explain why it worked every time they tested it at the shop though.

Maybe try in a different building? Perhaps the power to the building is questionable, and the PSU isn't able to cope with it. Seasonic PSUs should usually be pretty good though, and that would seem like an unlikely scenario overall. It just seems weird that it worked fine at the store.

Another thing possibly worth trying might be to update the motherboard's BIOS to the latest version, and/or clear the CMOS to reset the BIOS back to its default settings. You then might need to reconfigure some things though. And of course, that still wouldn't explain why it worked for them.

 

[Theriak25]

Thanks for the replies. I am going to try different building today, I will let you now. In case it has something to do with electricity in my flat, what are my possible options with that particular pc? Every other electric device and older pc's worked in my flat flawlessly.

I will try CMOS reset after that, we will see.

If nothing from above helps, I will make another trip to the shop for CPU check then.

 

[roberttim]

I doubt it's the bent pins on the CPU socket since you've done almost everything that I would have tried out if I was having the same issue.

 

[Theriak25]

First update: electricity is out of question now, tried it in a brand new house, problem persists.

 

[Paperdoc]

What you describe sounds like a intermittent bad connection. And that appears to happen when the computer case is bumped around. I doubt it is a bad connection in the RAM slots. I suspect it is something touching the bottom side of the mobo and causing a short circuit that should not happen.

ONE way this can happen is if the stand-offs that are supposed to be under the mobo are misplaced. In a case, there are some small items about ¼" high screwed into threaded holes in the back panel of the case, and then screws through the mounting holes of the mobo (usually three rows of three, but it varies) turn into these little stand-offs. The stand-offs establish clearnace between the back side of the mobo and the case's back panel. The mounting screws fasten the board to them securely and ground the mobo at those points. BUT there should never be any other contact points between the mobo back side and the case. If a stand-off is placed in the wrong position it can cause a problem.

From your post I do not expect that you are "handy" with disassembling and re-assembling your computer. So I suggest you take it back to the shop and have them inspect for this possible source of trouble, or any other possible way for there to be an intermittent short or loose connection.

 

[Theriak25]

Update:

First of all, thanks for all advices and opinions. The Situation has evolved. Last two days, my pc started to recognize both DDR modules. I didnt do anything, didnt try nothing mechanically-wise, pc just decided to suddenly show both DDRs. However somewhat the problem persists. When both modules are loaded, PC is unstable. Even walking near the case, which causes small vibrations in my floor, is enough to make PC reboot. It just restarts itself. When only one module is loaded, this problem is not present.

Only thing I did was downloading CPU-Z. After the first start of that software, it showed both modules, however task manager, or other third party fps monitor softwares did not. Next day, BIOS just started showing both modules, like other third party software.

Paperdoc: I checked the mobo, it doesnt seem it touches anything, however what you describe makes sense. I arranged an appointment with the pc seller, he is willing to swap my mobo and even memory modules with no charge, so I shall see. If the problem persists, next time we will swap CPU, as soon as it is available. I hope it will be solved. Will let you know.

 

[Paperdoc]

If any of seller's efforts to resolve this involve taking the mobo out of the case, whether it is replaced or not, THEN is when to check VERY carefully that all the stand-offs are in the right places and exactly aligned with the mobo holes. There should never be any stand-off where there is NOT a mobo mounting hole. Another error some make if they don't know: NO stand-offs! Most cases come with stand-offs pre-installed, but sometimes a few are in wrong places. But SOME mobos come with them NOT installed and in a bag. People who are not familiar with this may fail to use them at all, and that is almost guranteed to cause problems.