The PC of Theseus, or How I Changed Everything To Change Nothing

[JulsSkogs]

This has been a journey.

A week and a half ago I found my PC to not be outputting video. I had left it sitting idle overnight, no sleep or shut down. Peripherals still had power. Rebooted the system, nothing, not even the motherboard splash/boot screen. I had some artifacting happening on one monitor on rare occasion and having already started looking to upgrade anyway, I assumed it was the GPU. I checked all of the display cables to each monitor, tried HDMI instead of DisplayPort, the monitors themselves were getting video from consoles, etc. Tried resetting the CMOS and re-seating/swapping the RAM positions (two 8GB sticks of CMK16GX4M2D3600C18 from Corsair), still got nothing.

Bought a 6700XT, installed it  (and didn't remove it from this point forward), nothing. Took my system over to a friends, tossed his RAM (a single 8GB stick of M378A1K43CB2-CRC from Samsung) in my build and boom it worked. This led me to believe one of my RAM sticks had gone bad. Kept the one we deduced was bad out of the system and went home. Plugged my system in, started fiddling with going through the DDU process and puttinng this troubleshooting behind me, but decided to save it for the next day. Left my PC to idle. Woke up, ran DDU, and downloaded AMD's GPU management software. Rebooted, no video after. Assumed this was all coincidental and the "good" stick of RAM went bad. Used the magic of Amazon to get a 2x16GB kit of Corsair's CMH32GX4M2D3600C18W. Installed those and back to normal!

 

Until I rebooted to enable Smart Access Memory. After the shutdown portion of the reboot, no more video. So at this point I was convinced the motherboard must be shorting one of the RAM slots or something. Order a new motherboard, same model as the linked parts list BUT it was rev. 1.2 (referred to as 1.X in the documentation as far as I can find), rather than the original's rev. 1.1. Motherboard arrived yesterday and I went back to the aforementioned friend's place to try my original RAM in his system because we somehow overlooked doing that the first time. It booted right up with video, no problem. This further reinforced in my mind that my motherboard is the issue.

Wake up this morning and gut my PC (an excellent time to clean up some lazy cable management) and swap my motherboard. Excited to finally enjoy using my PC after a while and...you guessed it, no video! At this point, I'm considering just moving to a secluded cabin in the woods away from any and all technology. Now thinking it is obviously the CPU, I grabbed my 3600 that I had replaced with my 5800X3D and popped that in. Still, nothing. One stick of 2x8GB Corsair RAM, nothing. Two sticks in swapped slots, nothing. Other stick by itself? Nothing. Pop the 2x16GB of RAM in, nothing. One stick, nothing. Other stick solo? SOMETHING. I finally had video again, and all was running as normal. But knowing that I had to continue searching for answers and see if it was still going to replicate the problem, I regretfully restarted. Lost video, who could have seen that coming?

 

Try both 2x16GB sticks in swapped slots, nothing. Tried going back to my 5800X3D with the 2x16GB kit, nothing no matter the stick/slot combo. So finally, I do something that I likely should have done much earlier in this process and checked the QVL docs for both revisions of the motherboard and for both Vermeer- and Matisse-generation CPUs. None of the RAM mentioned in this post is supported. Which has now opened up even more questions in my mind, or at least creates further confusion around questions like "Why does it work sometimes and not others?" Looking over the QVL docs, they have a Sep. 2021 upload date on the Gigabyte website and I know Corsair has done a refresh of their RGB modules recently, so suppose it could truly a simple matter of none of the modules actually being intended to work in this motherboard but I have had the 2x8GB kit in the rev 1.1 motherboard for over 2 years now with no issues. How does that work? Is it a matter "well it could work but we're not saying that it for sure will, that's why it's not on the list"?  I updated the BIOS at the beginning of March when I got my 5800X3D and it ran with no issues until this mystery started. The QVL docs also show no support for any of Corsair's white RGB models, at least from what I can tell, and that seems strange given that, while they would be a different SKU, their actual compatibility shouldn't be any different than the black RGB sticks of the same spec, right? Do QVLs not get updated over time to factor in new model releases? Part of me wants to think that this could obviously be solved by just finding sticks of a supported SKU, but that just leads my brain back into wondering why the build worked for so long without an issue to begin with.

 

So now we're here. And I'm confused, looking like Charlie Day on the search for Pepe Silvia. The only thing I haven't replaced is the PSU, storage and cooling, and I can't imagine how any of those would play into this. I have basically built an entirely new PC at this point, and it is not meaningfully different in any way than when I started this process, I just have less money and more PC parts that I don't need. Does anyone have some sage wisdom? Is there something obvious that I'm just completely overlooking?

[JulsSkogs]

I've now tried swapping PSUs to my old ATX PSU and tried building the system outside of the case and still, nothing.