Help! My PC just died.

Got home, fired up my PC, and everything went sideways. My monitor keeps flickering like the tower isn't even receiving power. I can hear the hard drive trying to spin up—that clicking sound happened maybe three or four times—but there's just no picture. I tried restarting and power cycling it a few times, and during those attempts, the CPU fan actually cut out once or twice, and it took a few tries to get any life at all after that clicking noise. Interestingly, I think I heard the Windows XP startup sound once or twice, yet the screen remains totally blank. Any idea what the hell is going on? 🤷

Maybe try starting out by swapping in a different graphics card.

Maybe you're looking at a faulty power supply... if you can grab a different one just to test things out, it might be worth a shot...

So, I tried this: I hooked the monitor directly to the motherboard and got a picture. However, the fan on my graphics card is still spinning, so I'm not entirely sure if the GPU itself is actually the culprit. On top of that, the hard drive isn't booting up nearly as fast as it should be. As for that clicking sound I mentioned earlier—it’s definitely not coming from the drives or the DVD-ROM since I've unplugged everything. I can't pinpoint it exactly, but it seems to be coming from somewhere near the front panel power button and the reset switch.

It’s the graphics card. I pulled it out, cleaned everything up, and put it all back together, though I was a bit unsure about one specific wire, so I booted the PC just to check a photo. It powered right up—fans spinning perfectly, drives humming, even the image popped up full screen. Everything looked fine, so I figured I'd just pop it back in. But once I seated it and tried again, nothing. No display, and the drives wouldn't even spin up. I ended up pulling it out again, rebooted, and suddenly everything works perfectly again.
I suppose the question is whether the issue lies with the GPU itself or the slot. I only have one slot available, so unless I can get my hands on another PC, I'm a bit stuck.

Mahun, I already told you. Your power supply probably gave out. It’s the obvious answer.
Since the PSU is a component that handles constant load (including your HDDs and SSDs),
you should just buy one with more headroom right away—maybe 25-30% more wattage than you actually need. That's how you make it last for years. That is how it should be done.
If you just buy the bare minimum, you'll be replacing it in a couple of years. It depends.
Or maybe it’s something else entirely. Who knows? My crystal ball is looking pretty cloudy.