Question Holy Trinity: random black screen, CPU EZ debug light on, force shutdown required

[GEkiDit]

Hello Guys,
I built my PC 5 years ago and never had an issue I couldnt fix. I have had this problem for a couple of months now. It first occured when we got a new internet router(coincidence or not?). During gaming I get a black screen out of nowhere. The lights and fans are still on but the CPU EZ debug light also turns on. I then have to force shutdown because otherwise the PC wouldnt power down. I cant reproduce the problem because one day i can game for multiple hours and the other day it happens after 2 minutes. The only game that seems to work fine is Valorant. All others experience this problem.
Things I have tried (probably forgot one):

• memtest86
• BIOS reset
• clear CMOS
• BIOS updated to newest version
• Updated Chipset and GPU Drivers
• complete rebuild of PC , cleaned every component, applied new thermal paste, installed new PSU (old one got replaced by manufacturer due to unstable dc)

Note: after this step the PC worked fine for 2 days, the longest since the problem first occured

• sfc /scannow + repairing damaged files
• Windows clean install
• monitored temperatures when problem occured: hottest component (GPU) with 54° C right before end of protocol

HWiNFO showed that the "Power Reporting Deviation(Accuracy) sometimes drops to 70%, is that a problem?
In the reliability monitor I only get informed when it shuts down and not why. Sometimes it reports an unexpected shutdown when the pc was running but not being used.
My PC:

• MSI B450 Tomahawk
• Ryzen 5 2600
• ROG Strix Vega 64 OC
• G.Skill Trident Z 3200 CL16
• 500 GB SSD and 2 TB HDD
• old PSU: bequiet Pure Power 11 600W
• new PSU: bequiet Pure Power 12 650W modular

I feel like I am missing something very obvious. Any advice on the next steps and/or the possible cause of this is very much appreciated!

 

[Lutfij]

Welcome to the forums, newcomer!

MSI B450 Tomahawk
+
BIOS updated to newest version
Would give us some semblance as to which BIOS version you're on at this moment of time.

Windows clean install
Where did you source the installer for the OS? Might want to mention what version(not edition) of Windows 10/11 you're on. Did you install the OS in an offline mode, alter installing all drivers in an elevated command, i.e, Right click installer>Run as Administrator?

Can you drop in another processor into your build? If the issue doesn't persist then the processor you currently have is the source of the issue.

 

[GEkiDit]

Thanks for your reply!

Welcome to the forums, newcomer!

MSI B450 Tomahawk
+
BIOS updated to newest version
Would give us some semblance as to which BIOS version you're on at this moment of time.

My current BIOS version is: 1.J1

Windows clean install
Where did you source the installer for the OS?

Directly from the Microsoft website with the Media Creation Tool.

Might want to mention what version(not edition) of Windows 10/11 you're on.

Microsoft Windows 10 Home (x64) Build 19045.3930 (22H2)

Did you install the OS in an offline mode

No, I installed it via the ISO file

, alter installing all drivers in an elevated command, i.e, Right click installer>Run as Administrator?

Did not do that. Will try.

Can you drop in another processor into your build? If the issue doesn't persist then the processor you currently have is the source of the issue.

Unfortunately i do not have another processor.

Yesterday I switched the RAM sticks. PC didnt boot! Tried each one alone. One booted, the other didnt.
Is it the RAM?

Thank you very much for your help!

 

[GEkiDit]

Sorry for the late response, was gone for 2 weeks. I have tried everything you suggested except replacing the CPU. Problem persists. The RAM thing is completely random: sometimes a stick works and sometimes it doesnt. I read somewhere that manually adjusting the frequency of the HBM of the vega solved the issue for that user. Tried that and now I completely baked my PC. It wont post anymore. If I reset CMOS with the battery removal I can go into the BIOS. Then I resetted the BIOS to default to rule anything in that direction out. Saved and rebooted: still no boot. The loading circle with the dots starts to spin (sometimes) but then I get a No Signal from my monitor. Then the red CPU led goes on (also sometimes). Took the GPU out to confirm a proper connection via PCIe. Noticed it was really hot, but there wasn’t any load on it. I guess my Vega just died🙁

 

[GEkiDit]

Vega works fine in another pc. I was now able to test every component in another system except for the CPU/MoBo. As I was planning on upgrading them before all of this started, I will just do that.