Question System Shuts Down After 10 Minutes

[braxus]

I got a new larger case to fit a 4090 GPU into. I havent got the GPU yet. I managed to swap all the parts from the old case to the new. All seemed fine for 10 minutes until the system shut itself down instantly. It wouldn't boot up again right away. So I was worried I overheated my CPU, so I let it cool down. After 20 minutes, it was able to go to boot screen, so I got into the bios. I watched the CPU Temps while letting the system run in the bios screen. It never went above 33 degrees C. Again after 10 minutes the system instantly shut down. I don't think it's the cpu, but can't be sure. Is the PSU detecting something I'm not aware of, hence shutting down? Not sure what to check at this point. My system is in my signature, but for those who don't see it, it's an AM5 7950X system that was running fine before the swap.

 

[braxus]

I checked the cable connections, especially the loose cables with power going through them. I put electrical tape on the ends of the connectors not being used. Powered it all up again and ran the bios screen for 1/2 hour. Didn't shut down yet, so I booted to Windows. Running that now. Maybe some connector was grounding out somewhere? I'll keep the system on till it does something again. When I was in the Bios, the CPU temp was 33 degrees C, the system temp was 37 C, the PCH was 54 C. I'll also need to check my cabling as two of the front fans aren't on, so I missed some cables for those.

 

[LabRat 891]

I checked the cable connections, especially the loose cables with power going through them. I put electrical tape on the ends of the connectors not being used. Powered it all up again and ran the bios screen for 1/2 hour. Didn't shut down yet, so I booted to Windows. Running that now. Maybe some connector was grounding out somewhere? I'll keep the system on till it does something again. When I was in the Bios, the CPU temp was 33 degrees C, the system temp was 37 C, the PCH was 54 C. I'll also need to check my cabling as two of the front fans aren't on, so I missed some cables for those.

I'd bet you had a 'loose' cable that was resistively-heating and de-seating itself in expansion. When it cools off, it would make 'seemingly, good-enough' of a connection.
I've had this kind of thing happen several times, non-destructively. Sometimes the pin(s) in the plugs get dislodged too; reseating (usually) will also push those pins back in.

The 'similar' situation that I still have no explanation for, are plugs needing to be reseated after a power outage.
Yeah... that doesn't make sense, I know. Why would the DC-side power connectors need re-seating, when AC Mains has been suddenly cut?
IDK, but It's happened to me at least half-a-dozen times over the last 15+ years, and across 3 different states with 3 different environments.