PC froze and now won't turn on

So, just like the title says—everything suddenly froze. Mouse won't move, keyboard is dead, nothing. It’s just stuck staring at the desktop. I tried hitting the power button on the case, but it wouldn't budge. On the second attempt, it actually booted up, ran for maybe ten minutes, and then froze again. After that, it just died completely. Now, it won't even turn on. I’m hearing this weird beep, too—not every single time, but enough to be annoying—and then, nothing. Just silence.
I'm trying to wrap my head around which part actually kicked the bucket here. I ruled out the hard drive because, well, if the drive was the issue, I figured it would at least try to boot into DOS or throw some kind of error message. Power supply seems fine since the lights come on normally. And I don't think it's the RAM either, because again, I'd expect some sort of BIOS error or a boot attempt there.
Basically, using my "expert" amateur logic, I've narrowed it down to the motherboard or the CPU. Though, honestly, I've never had a CPU die on me before, so I have zero clue what those symptoms actually look like...
When I try to power it up now, it gets juice, but it won't actually start. The LEDs light up, but the fans won't spin and nothing else happens.
I'm in a bit of a bind because I've got some work to finish by Friday and I have no idea what parts I need to swap out. It doesn't help that this thing uses an old LGA 775 socket, which is pretty much ancient history at this point, but hey, I guess I can hunt something down on Craigslist if I figure out what's broken.
For context, the motherboard is an ASUS ROG Maximus and the CPU is an Intel Core i7 or something similar.

Thanks in advance for any advice you guys can toss my way.

Look, you should probably grab a different power supply from a friend or somewhere else just to test things out—and while you're at it, double-check all those connectors running from the PSU to the motherboard to make sure they're actually seated properly. The PC will still attempt to fire up even without a CPU installed, so that really narrows it down: the issue is either sitting in your power supply or it's a problem with the motherboard itself.

Benjamin King2 said:Try borrowing a different power supply just to test things out—and definitely double-check those connectors going from the PSU to the motherboard to make sure they’re actually seated right. You can technically fire up a PC without a CPU installed, so the culprit is likely either the power supply or the motherboard itself.

Man, thanks a ton—you've been a huge help here since I'm basically a total amateur when it comes to IT stuff.😁 😁I mean, I know how to put a rig together and install software and all that, but when it comes to the technical deep dives? Yeah, I'm a bit of a klutz.
I'll try to scrounge up a spare power supply to test. Even though this was a pretty pricey Corsair RM650, it might still be worth it compared to hunting down a motherboard or a processor—which would be a nightmare given they're old Socket 775 parts. Still, my gut tells me it's the motherboard.
Besides, what would cause the optical drives to spin up if the power supply wasn't doing its job???

It doesn't necessarily mean the thing is completely fried—it might just be failing to push enough juice to all your components. That is, assuming there's actually an issue with it to begin with. Which is why I’m telling you to swap it out and test a different one; you have to play the substitution game if you ever want to pinpoint which specific part is acting up.

Benjamin King2 said:It doesn’t necessarily have to be totally dead—it might just not be pushing enough juice to all your parts. Assuming there's even an actual issue to begin with. That's why I'm suggesting you swap things out; you've gotta test the components one by one to figure out which one is actually acting up.

So, I went ahead and tore the whole thing down and put it back together, and now... weirdly enough... it's running perfectly fine. The real question is how long this lasts before it acts up again. Honestly, part of me almost wishes it would just die completely—that way I'd actually know what needs replacing.

Honestly, it’s entirely possible some connector just wiggled loose—maybe the ATX or the CPU power cable—and that was the whole reason it was acting up. Anyway, problem solved. 🙂

So, the damn thing started shutting down on me again—totally froze up, wouldn't even boot. Turns out the connector was just acting loose, so I popped it back in, snapped it shut, and it's running again. But then, of course, it decided it needed to run a Windows repair, and wouldn't you know it... for the first time in two years, it’s throwing that "Windows is not genuine" error at me. It's like the system is getting all sensitive or something. I've actually noticed before that if I move the case even a little bit, it tends to hang.

So I just gave it a shot—and seriously, if I even tap it or nudge it slightly, the whole thing just freezes up. And I’m telling you, all the connections are seated perfectly fine.

Then it won't even boot up right away; it just keeps trying itself over and over until it finally catches.
And then DOS just throws an "overclocking failed" error at me...
It’s like some kind of loose contact or something went sideways with the hardware...

If you have a friend who works in the field, or if you can find someone through a professional contact, I’d suggest handing it over to them to take a look. This isn't really the kind of thing you can diagnose from a distance; you need eyes on the hardware to know what's actually happening. You might be able to narrow it down using some trial and error, much like how Benjamin King2 suggested

Brian Campbell6 said:I just gave it a shot—the second I tap it or even give it a little nudge, the whole thing freezes?????? And I'm telling you, every single connection is seated perfectly.

Then it won't even boot up, so it just keeps trying over and over until it finally catches.
And then DOS just spits back "overclocking failed".........
It’s like some contact is totally shot...

That isn't a DOS issue, it's the BIOS. You should check the BIOS to see if the date got reset; if it did, you probably just need to swap out the CMOS battery on your motherboard.

Regarding this thing about it not wanting to boot until you jumpstart it—which power supply are we even talking about? I'd probably just crack it open and check if any of the capacitors look blown or bulged up

Benjamin King2 said:It’s not the DOS thing—it's the BIOS. You should check the BIOS settings to see if the date got reset or something; if it did, you probably just need to swap out the CMOS battery on the motherboard.

Yeah, okay, it's the BIOS... I don't know why I kept blaming DOS, my bad. But wait, how am I even supposed to go about checking the date in there?🙂

fadedorca66 said:Regarding that part about it refusing to boot until you give it a little kick—which PSU are we even talking about here? Honestly, if I were you, I'd crack the casing open and take a look at the capacitors... see if any of them are looking all bloated or busted.

Corsair TX 650

Brian Campbell6 said:Right, I meant BIOS—not sure why I kept typing DOS, honestly. How am I even supposed to check the date?🙂

Just hop into the BIOS and check there. Usually, when you boot up a Dell, the screen will tell you to "press ... to enter setup" or something similar.

On my end, if the system time isn't set correctly on Windows XP, I usually find myself having to reboot immediately after the initial startup. Once I get the clock adjusted, everything tends to run smoothly again.

Benjamin King2 said:Just hop into the BIOS and take a look. Usually, when you're booting up a Dell, it’ll pop up a little message on the screen saying "press ... to enter setup."

Looks like the date got reset back to whenever it left the factory... probably July 1st, 2009.
Might be worth messing around with the battery. Thanks anyway—honestly, I wouldn't have even thought to check this myself.

Just go ahead and load the default settings in your BIOS right after you swap out that battery.

Benjamin King2 said:Just reset everything to the default BIOS settings once you've swapped out that battery.

Man, I have no clue how to do that part. So, I swapped the battery, switched the boot priority from the floppy back to the hard drive, and fixed the clock. Everything seems fine—mostly—except for this weird thing where the BIOS flashes "Adapter 1 no HDD found" for a split second during startup... I'm stuck on how to fix that. On the bright side, it isn't freezing anymore when I move the case or bump it—well, at least not yet. Maybe a loose connection finally settled itself out.

Edit:
Anyway, I’m actually typing this on the machine in question now.
Everything feels mostly normal, but the startup sequence is acting a little funky. First, the fans kick on, then they go quiet after about two seconds, and suddenly this Asus express gat pops up—which has never happened before—then two seconds later it tries to boot again, the fans spin back up, and it finishes the job. It all works, except for that annoying "Adapter 1 no HDD detected" message popping up right at the start. Still, it gets me into the OS just fine.

If it works, who cares? 😁 I guess it might be worth grabbing the manual from the motherboard manufacturer just to see what's actually going on

fadedorca66 said:I mean, if the thing actually works, does it even matter? 😁Though honestly, you're probably better off just grabbing the manual from the motherboard manufacturer and giving it a thorough read so you aren't flying blind

Yeah, doing that would definitely be the smartest move here.😁