Question PC can work normally but sometimes it doesn't? No Event Logs to see what happened.

[Ventormentor]

So, my PC is odd.

It's been reliable for several years and it's still DDR3 (Planning to upgrade to DDR4 when I can).

Sometimes it makes me think I need no upgrade, but other times it makes me think it's time to dump DDR3 now, but then I try one last time to test my PC and it works fine again... This time, it lasted 2 weeks until the freeze began again. Good times.

But anyways, PC generally it's ok. Can go to YouTube and watch stuff while I play an idle game and I play Runescape, all at the same time. Absolutely no issues on good days for hours, even my lil bro plays after I go do something else, so add some extra hours of use with no incident.

But on the really bad days, 5 mins in a vid is all it takes for a total system freeze that can shut off my PC fully, then it will reattempt a restart, only to freeze on the ASUS logo and restart again, then it begins a "1 sec" boot loop, forcing me to shut off the PC fully by turning off the surge protector.

That time, it was different... Finally I got a BSOD: "IRQL Not Less or Equal", but left no dump... Ironic, because the other total freezes just stopped on the last frame of something and shuts itself off afterwards with no BSOD at all...

What's going on? What could be failing in my PC that gives no signal of failure? Everything loads properly. No signs of garbled crap or errors loading stuff, no graphical glitches, temps are fine, and I did a clean Win reinstall and nothing fixed that. (That was a risky move, by the way, if my PC decided to act up in the middle of the reinstall, specially since it can freeze before POST).

What is happening to my PC that can fake good health, but at the same time, it shows me something is failing that I cannot pinpoint the cause?

Thanks for reading.

 

[Lutfij]

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list the specs to your build like so:
CPU:
CPU cooler:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the age of the PSU apart from it's make and model. BIOS version for your motherboard at this moment of time?

 

[Ventormentor]

Let's see...
CPU: Intel I7 4770
Cooler: BeQuiet! Pure Rock Slim
Mobo: Asus B85M-E
RAM: No idea, but it's 4 sticks of 2GB each.
SSD/HDD: The HDD is a Toshiba, which is quite old, but the SSD is a ADATA, pretty new-ish of 1 year.
GPU: GeForce GTX 1060 6GB
PSU: Corsair VS600 (Black/White, not the awfully bad Orange label)
Chassis: Generic mid-tower, but works.
OS: Win 10
Monitor: AOC 913Fw
PSU age? Like 1 and a half year?
No idea about the version of the BIOS, but the Mobo itself had its last update in 2018.

Anyways, not sure the relevancy when I say my PC can work normally, but on bad days, it freezes and shuts down, then boot loops for no reason.