[SOLVED] PC going into hard stops or restarts every 30 mins

Yeah, that sounds like a PSU problem. Try using another PSU.

In which case you could try a hardware monitor like HWiNFO, look at the sensors section and read what the voltage reports are for the motherboard (particularly +3V, +5V and +12V readings). If actual values are widely different to what they should be (at least 5% difference), then it could indicate a problem with the PSU.

BIOS might also have this info as well.

The voltages are within the norms, so PSU shouldn't be an issue.

Something odd due to the observable behaviour of cutting out due to power loss. Perhaps a different component... do hear/read about VRMs on a motherboard could overheat and impact performance. Beyond what I know though.

What are full system specs? Perhaps someone might see something about the particular combination or have experience with them.

Still hoping someone with experience will chime in (if keep the thread going long enough it should attract attention).

At this point has there been a change in the temperature reading you mentioned? While it's possible the sensor could be faulty (what is it at idle?), a good cleaning up of dust or even reseating the CPU cooler might be worth considering just to rule out the possibility of it being a thermal issue. On that note, what is the cooler you're using at the moment?

The increased load observation still seems, to me, to point to something about power or thermals.

If a software issue, then a clean installation of Windows would be the 'nuclear' option. But it would get rid of it (unless it's a particularly bad virus or something).

There are some HDD health checking software out there which you could run to see if the HDD is fine. Crystal Disk Info is one I'm aware of; and someone here has mentioned one called HD Sentinel. Some manufacturers might even have their own software. Most hardware monitors should be able to read off the SMART information on the drive itself too. Might be worth having a look.

I had a similar problem with instant restarts. Without warning, while in-game for 1 to 2 hours the PC would simply restart - the Windows startup logo would be on screen as if I had just turned it on. I had kernel-power event 41 in event viewer and a few other errors, but nothing I could pin down as the cause. Speedfan was logging temps and they were fine, cpu around 60c, gpu 74c, mobo 51c. I suspected software while worrying about hardware (hopeful). I have a 2080 ti in an ITX-mini mobo with a 800w SFX-L psu and worried my system was being strained. Anyway, for several months now it bugged me that my screen saver wouldn’t kick in anymore for some reason. I thought maybe it was the Performance power setting so I had set it to Balanced quite a few weeks ago. I believed that was when my PC started insta-restarting, but I can’t be sure. I switched it back to Performance and I had another restart, so no luck there. I also checked for mobo and nVidia updates, but no luck after installing any of that. Also ran memtest for 14 hours and no errors. Anyway, about a week ago, which was after the several restart incidents, Windows pushed the October update to my PC. Along with it came some kind of Intel update, the exact phrasing of which I don’t remember, with a version number that, when googled, returned no results. Anyway, after these two updates my Screen Saver was working again! Since then, I gamed for about 1 to 1.5 hours without a restart. I’d like to test it a bit longer, but it looks like one of the two Windows updates fixed both the screen saver and the restart problem. I’m thinking the Intel update might have been microcode, but I’ll have to follow up on that. I vaguely remember there being an issue with restarts after Intel pushed microcode that patched Spectre and Meltdown. OP, did you install any Windows updates recently which you might be able to attribute to your problem going away?

UPDATE:
So I gamed for 4 hours last night and no restarts. Exact wording of the Intel update was "Intel Corporation - SoftwareComponent - 11/25/2018 12:00:00 AM - 2.2.100.47975" and I still can't get any google hits on that full version number. It does seem to track back to a microcode update related to Intel SGX. Check your Windows Update history to see if you have a similar item listed. I'm betting this was what fixed my insta-restarts, because I did nothing to my hardware during all of this. Didn't even pop the side off the case. I'm fairly certain that my problem was software (firmware) related.