My PC fell onto my scanner and now suffers from random shutdowns

Hey, first post, in need of advice.
So I knocked my tower over with a left elbow by accident, falling off of my desk and onto my scanner. My scanner is done for, but the tower seemed fine - iTunes didn't skip a beat throughout the split-second ordeal.
Upon its return to the desk, the tower seemed fine. Then, about 5 minutes later, it shut down. I waited, and restarted it, and it worked great for the rest of the evening. I shut it down before going to bed.
Now, this morning, it ran CHKDSK on my Windows-installed drive, C:. It deleted a few corrupt entries, and then started normally. I logged in and let it do its thing, decided to just let it run, and came back about 15 minutes later, and it was on the "locked out" screen. I signed back in, and everything was fine. I opened up My Documents, scrolled down, and then boom - complete and utter shutdown.
I should point out that at some point during its construction, I must have gotten a wire crossed, because it will never, ever stay turned off unless I turn the power supply off - if you just shut it down, it will turn on after about 5 seconds. But this time, it stays off. And it actually takes about 10 seconds to turn it back on.

Now, I've noticed that the shutdown only occurs when I try to run processes on it. Leaving it idle will net no response, but any attempt to open up a browser or program results in immediate shutdown.

I've checked out everything with a mini mag light, and I've had to blow a lot of dust off (it's really dirty, I'm lazy and haven't been cleaning it regularly). There's also a fair amount of thermal paste on the chip, and I'm waiting to get some more thermal grease before cleaning it off.

So I think it could be one or more of three things: the C:\ disk is corrupt/cracked/loose, my power supply is shorting, or my chip is cracked. I wouldn't think that thermal paste would be the complete answer, but I imagine if it's heat-related that it has a hand in it.

Either way, I'm in need of help. And if anyone knows why the never-stays-shut-down thing happens, that'd be swell too.

I should also add: ASRock motherboard, Intel chipset, Western Digital blue caviar HDs, can't remember the power supply offhand, and currently running windows XP.
 
If the CPU has sustained damage it wouldn't work at all.

I'm not really overly sure what the issue is, it sounds software related, but then I can't think of any process that would cause immediate shutdown of the PSU.

It could be heat related, but the computer would freeze from the CPU overheating under load and therefore thermally throttling down to reduce temperature. It wouldn't in my experience "order" the PSU to immediately cut all power, unless this is a safe guard through the motherboard I'm unaware of.

I would check the CPU cooler all the same. Does it still feel rigid on all 4 corners, or does the cooler frame now have play when you rock it side to side? Its possible the impact has dislodged one or more pins holding the cooler to the motherboard.
 
Just to add to Leeky above.

I have had motherboard protection in the past from a overheating CPU; It's called "C.O.P" (CPU overheating protection). it comes with most old ASUS boards and it issues a shutdown call when the cpu temp gets above around 70 c.

I'm guessing this chap means normal shutdown as opposed to a full power cut (?).

I agree though, sounds like the heatsink might have come loose here.
 
Definitely did. Took it off, examined the pins and noticed a couple weren't closing properly. Took me a while to get it back on, but the pins hold now - after some jamming - and it seems pretty stable.

Still backing up onto a terrabyte harddrive just in case the magic smoke starts leaking out.

Thanks!
 
Back