PC won't boot up - help needed!

Greetings,
I am dealing with an issue that I honestly cannot wrap my head around. Every time I power on my PC, it dies almost immediately—it runs for about a single second before just cutting out—and then, after a few moments, it triggers itself back on automatically.

Once that happens, about two out of three times, everything seems fine; it completes the boot cycle and operates perfectly. However, it frequently refuses to boot entirely, leaving me staring at nothing but a black screen.

The exact same thing occurs whenever I try to wake the system from sleep mode.

I haven't observed any signs of overheating or anything of that nature.

Thank you.

Have you taken a quick look at your temperatures just to be safe? I mean, check the CPU, the motherboard, all that stuff.
Maybe try swapping in a different power supply—borrow one from a buddy if you can—but don't grab some bottom-of-the-barrel unit since I'm not entirely sure what your actual setup looks like.

It could also be an issue with the graphics card; I actually dealt with something pretty similar recently where it would boot up half the time and just fail the other half. If your processor has integrated graphics, try plugging the monitor directly into the motherboard instead of the GPU to see if that changes anything.
Also, take a peek inside the case to make sure it isn't just choked with dust... double-check all your cable connections and things like that; honestly, you just have to work through the process of elimination.
You should probably run a scan on the hard drive using HD Tune (and please, don't just do a quick scan), and maybe install CrystalDiskInfo or Hard Disk Sentinel too, just so you can get a real sense of the drive's health.

Just let us know what your full specs are.😉

EVGA SuperNOVA Series, 430 Watt, ATX, EPS12V, PS/2, US Version
NVIDIA GeForce GTX Series 2GB 860m PCI Express.
Transcend DDR3 2x4GB 1333MHz, JM1333KLH-4G
The Asrock FM2 FM2A75M-HD is a budget-tier motherboard that serves its purpose if you aren't looking to push boundaries. It’s an entry-level component designed for basic functionality rather than high-end performance. If you're just trying to get a machine up and running for standard tasks, it functions adequately, but don't expect anything more from it.
Intel Core i3

Just like @wanderingpanther68 mentioned, there could be a dozen different things going on here—it’s hard to say for sure without more digging. I'd suggest starting with the power supply, though... just to rule it out. Also, when was the last time you did a clean install of macOS? You know, like actually formatting the drive and starting fresh with a clean OS installation?

Honestly, it could be anything from a simple overload to a thermal issue. You might want to grab something like Speccy or a similar utility; those tools can pull temperature readings for pretty much every component in your rig—motherboard, hard drive, CPU, RAM, GPU... I’m not entirely positive if it hits every single one or just most of them, but you'll get a good idea. I’ve even heard stories where if you have way too many fans running at once, the system might actually trip a circuit or shut down right at startup due to the power draw, though don't quote me on that.

I'd probably start by flashing the BIOS and resetting everything to the factory defaults. Those ASUS boards on Intel LGA 1151 can be pretty finicky; I've dealt with my fair share of nonsense with them myself.

wearycrane15 said:Honestly, it could be anything from a simple overload to a thermal issue. You might want to grab something like Speccy or a similar utility; those tools can pull temperature readings for pretty much every component in your rig—motherboard, hard drive, CPU, RAM, GPU... I’m not entirely positive if it hits every single one or just most of them, but you'll get a good idea. I’ve even heard stories where if you have way too many fans running at once, the system might actually trip a circuit or shut down right at startup due to the power draw, though don't quote me on that.

I mean, how many fans could you actually have that wouldn't pull any real power?🤣