Just a guess, but it looks to me this related to the way power is drained from the PSU. Meaning, the PSU is fine, but something causes your system to suddenly drain a peak of power from your power supply, and causes the system to shut down. The most likely culprit is the motherboard itself, or the CPU ( although a CPU failure would perhaps be likelier to develop through blue screens ) , but the GFX could also be the cause ( either through the PCI-E or through the power connector ), or a faulty / degraded connector somewhere ( causing a spark that causes an emergency halt )

To debug this, the solution is first to disconnect everything and check all connectors. I hope you have a modular PSU. check that all wires are firmly seated in the connectors. Then reconnect the essential ( OS drive, MB) and if possible use a basic low-end GFX . If the system still crashes then, the omen is pretty bad. If not , then gradually re-connect other components


The smell test is useful, indeed. But if the smell is strong enough to be noticed when opening the case, it might be a bit late... still, as funny as it seems, smelling while visually inspecting a component, like a GFX, makes a lot of sense

Well, guessing game...
Your cpu temps are surprisingly low, can you trust your sensors? I'd rather guess it's a malfunctioning temperature sensor and your cpu is simply overheating.

I think this is most likely the issue. Mine acted in the same way, and as those caps that bulge are usually on the power conditioning circuits, any disruption in them causes the comp to shut down.

Well I guess the question coming to mind if you recently put in the RX 480 is a no... Seems the default settings on that card draws more power from the motherboard than it should (exceeding 90watts vs the 75watt limit).

After replacing the the power strip and video card, it still shut off randomly.

Now it's having other glitches, like not recognizing hard drives at boot.

It's obvious now, the motherboard is failing. I've purchased a new one.

Thanks for all your suggestions.
No, I purposefully run a very lightweight version of Linux and turn off all extra visual flash in Windows. I like a responsive OS. The heatsink is also really good. 40 C was with the case on. With the case open, it's 32 C.

I also tested an earlier version of the bios that didn't control fan speed very well and temps were more around the 56 C range while idling.

Of course, when running a game it gets hotter, but the pc only seemed to shut down when the processor was under 40 C, like browsing the web or other lightweight programs.


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Thanks to everyone. It was the motherboard. Up and running with a new motherboard now.