Has this system always behaved like this or did this only start recently?
Doesn't seem to say much other than the PC has rebooted. If you press Start>>>Reliability>>>Click view reliability history. It may tell you a little bit more around the time the system shutdown. The Event Viewer is stuffed with so many log entries it can be trickier to see what's going on.
From my experience hardware errors don't often leave much of a paper trail.
Damaged pins on the CPU can cause problems, it's also possible to get a faulty CPU. However CPU hardware problems are quite rare relative to those of other components. I've never had a faulty CPU personally.
It doesn't sound like it is RAM if it's passed memtest but sometimes it can take a long time to fail. Your RAM is relatively low latency, you could try disabling XMP to see if that makes any difference just in case your CPU/motherboard is a bit picky.
I've had to troubleshoot these sorts of issues before, unfortunately it can be very difficult without spare components.
The system is about 8 months old, I believe the first lock up issue started 4 months ago, and persisted through Clear CMOS, and Fresh Windows, and I believe a BIOS update, but I can't quite remember, I did just update the BIOS today tho, maybe that will help, but I suspect not. The shutdown problem started when I installed the new UPS but as I said, I tested it off of the UPS and it still happened.
I did check the reliability history, that report on the right came from there, and it was listed as a hardware error and the Event viewer named the source as "KernelPower" I checked the keywords listed and they seem to indicate it was a power issue as well, but then listed a bunch of fixes like turning off Fast Boot, updating the graphics drivers and such, so who knows really lol.
Here is the Reliability History
Again, I don't see anything that stands out as a cause, but there are other apps that stop working at other times, I never noticed any issues at those times tho. The first 2 images are the complete shutdown, and you can see "Hardware Error" and the last image is when the system locked up but didn't shut down. No hardware error, just a note that the system
didn't shutdown properly as I had to hit the switch to restart it. Not sure what to make of that exactly, but I agree, I don't think there is much of a paper trail here.
As for the CPU, I have never had one go bad either, as I said, I assumed it would be all or nothing, but I'm probably wrong about that. I do however inspect the pins carefully upon install and use extreme care, so I don't believe that to be the problem anyway, but I may have to pull it and check as a last resort.
For the RAM I did triple check compatibility, I did get the low latency, but it was listed on the QVL for the MB and other lists, so unless I lost the silicon lottery really bad and the CPU can't handle it?. Also, I believe I did try running it at at base settings before and the lockup still happened, I will give it a shot tho as that was before this new shutdown problem. And when the lockup happens, the DRAM Q-LED is lit indicated a RAM issue, that is what prompted me to do multiple memtest runs, but since those came back fine, I started to suspect the MB or the PSU, and now I am leaning PSU after this new problem started.
Yes it is very difficult, I normally can fix most problems myself, but for this I figured I would appeal to better experts than myself. I use to fix computers for friends and considered doing it for a living until I realized the pay doesn't match the skill needed. But I have fixed desktops, laptops, replaced phone screens (the glued on ones, now the screw on ones) and only failed once when I was tired and made a sloppy mistake lol. But all this to say I am not new to this, I just have reached a point where "phone a friend" seemed like a good idea whilst still troubleshooting to both confirm my thinking and get some different views on it.
I do appreciate your input