The other day I was playing Left 4 Dead 2 when suddenly, without warning, my computer simply shut down, as if the power plug had been pulled out. I tried restarting it, but nothing (NOTHING) happened. No fans would turn on, the mobo would not post, it was just dead. I opened up my case to see if something important had simply come loose, but found nothing unusual. I tried again, and all I got was a very brief (fraction of a second) flash from the mobo's troubleshooting LED's (to brief to even bother deciphering), and one of the fans started up, but again, only for a small fraction of a second. I took my computer completely apart, put it back together, but still nothing.
After some thinking, I realized it was most likely that the power supply had died. It was an Antec Basiq 550W. My cpu is an AMD Phenom x4 9650 oc'd from 2.3 GHz to 2.8 GHz (which had been running stably for over a year), my gpu was a pretty new eVGA GTX 460 SSC edition (I just got it about a month ago), and then of course RAM, some hard drives, fans, etc. I figured 550W must have just not been quite enough and it finally buckled under the pressure (although I had played L4D2 for many hours on it with that same setup with no problems.)
So I went to a local electronics store which fortunately had a pretty good deal on a Zalman 850W psu. This would certainly be more than enough for my system, so I bought it, installed it, and to my delight, it started right up again. Then, since I had cleared my CMOS earlier in trying to fix my initial problem, I was playing around with it trying to get it back to its original oc level. At one point I had it at 2.6 GHz, ran Prime95 for 10 minutes (obviously not very long, but the temps plateau-ed at around 65C.) Then I decided I would try playing Left 4 Dead 2 again, mostly just to see how stable it would be. And after maybe 10-15 minutes, to my horror, it shut down again and would not turn back on. Just like before. I can probably return the Zalman psu to the store (or exchange for a new one), but I'm seriously afraid my computer will just destroy another brand new, perfectly good power supply.
Does anyone know why this could possibly happen? I can imagine my computer maybe just shutting down due to instability, but to totally wreck the psu?? They are supposed to have all sorts of failsafes against this, like overvolt/overcurrent/short-circuit protections. And this was not some no-name cheapo psu either. Could it possibly be due to my motherboard somehow? It is an MSI K9N2 SLI Platinum, not quite 3 years old. Or maybe it's just my attempts to overclock? I could just leave it at its stock clock speeds if I need to. Please, anyone, I have never encountered such a precarious problem and I'm afraid to even try anything again!
I would really like to believe that this is just due to an odd coincidence, but my (perhaps slightly paranoid) mind tells me it's just too much of a stretch to believe that a power supply that I just put in to replace an old one that suddenly died could also suddenly die within hours of being installed and that the two events are unrelated.
But then, I have no idea how a power supply can just die like that! It's not like I jammed a fork into its circuitry and stuck a neodymium magnet on it just for fun. My computer is plugged in through a surge suppressor, and there were no thunderstorms or anything like that lately (I live in Minnesota!)
So should I just go exchange the psu for a new one? It was really quite a good deal, a trusted brand name 850W psu for only $99. But what if that breaks? Returning it broken once to the store will most likely not raise any eyebrows, but twice within the span of a couple of days might seem a tad suspicious. It doesn't help that I used to work there a couple years ago, so I could very well be recognized. And if I did try again, I don't know if I'd ever be able to play Left 4 Dead again, which is too bad because I'm quite addicted.
Has anyone ever heard of something like this happening, or even just have a guess at what might be causing it (besides random chance)?
I replaced the Zalman psu with a new one, and once again, my computer still wouldn't turn on. No fans spinning, no post, nothing. Frustrated and desperate, I disassembled my whole computer, replaced the standoff screws on the motherboard, changed to a different surge suppressor, and even a new power cord. Moment of truth, I hit the power button, and...FFFFFFUUUUUUU---!!! Nothing. I was about ready to bring my computer in somewhere and pay some ridiculous fee for a diagnosis service, but before that I figured I'd try messing around with things a little bit more to see if out of blind luck I would come across a solution. At this point I was fairly certain it must be my motherboard, so I was playing around with the ATX power connectors to it.
And then something unexpected happened. I had taken out my video card to get easier access to the cmos battery which I thought I would try replacing. Then when I tried turning on my computer to see if that had worked, it started booting up! But as I later discovered, it had nothing to do with the cmos battery. I had forgotten to put the video card back in before I hit the power button, and when I put it back in, my computer returned to being a lifeless black box of s***. So my video card was the problem!! My brand new Geforce GTX 460 which I had bought not more than a month ago. Fortunately I still had my good old Geforce 9600 GT, so I put that in and my computer booted up just like normal. And evga has good customer service, they have an actual phone number you can call and actually talk to someone, so I'm going to RMA the card (it just sucks that it will be about 2-3 weeks before I have a replacement.)
So although I solved one mystery, I opened up perhaps an even larger one: Why the hell would a video card cause a computer to become so totally and utterly unresponsive? I can see maybe a broken card resulting in no video output to the screen, but the computer should at least try to start booting up, or at the very least the case fans should start spinning. Unfortunately I don't have another computer around with a pci-e slot to see if it would do the same thing to it. Computers are weird.