How do I tell if my Power Supply Unit is going bad?

For starters, I'm a software guy, not a hardware guy. I'm able to diagnose certain hardware issues, but not very many at all.

My primary system continues to crash rather badly. Just in the middle of WoW, it dies. I don't think it's heat-related since when I am able to bring it right back up (which is not always, hence this thread), the heat monitors in the BIOS don't seem to indicate anything outside of well-accepted norms for the processor, MB, chipset, case, etc. This particular crash is just a general freezing of the system.

Anyhow, here's the rub: I'm not always able to restart it just yet. In fact, it has been acting that way for some time now even after normal shutdowns. Basically what happens, after the system is off (through whatever means, a normal shutdown or a crash), it is unable to start again. I hold the start button down on the case and the fans spin up for about half a second and then stop. Immediately after stopping, they spin up again for the same amount of time and then stop. This goes on as long as I hold down the start button. Since I have a clear side to the case, I can see that the motherboard lights "pulse" right along with the fans.

Certain things seem to fix the problem. Like unplugging the computer for a while. The time required to get this fix to work seems to be random, though.

I haven't seen anything (but again, I could easily be wrong about this) that would indicate the motherboard is at fault, so I find myself left blaming the power supply unit.

Any ideas?

Thanks in advance.

P.S. - This has happened before but it only took one restart cycle to get it working right again and it was usually after a fan had failed causing the system to overheat rather badly. I hadn't thought anything of it until recently when it started to do this after normal shutdown as well as horrific events.

Fans spinning up and the system failing to completely power up seems to indicate a motherboard problem to me.

It could be some freak power supply problem, but I wouldn't bet on it.

Got any spare power supplies lying around?

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Originally Posted by 'mmcookies',index.php?page=Thread&postID=212082#po st212082

Fans spinning up and the system failing to completely power up seems to indicate a motherboard problem to me.

It could be some freak power supply problem, but I wouldn't bet on it.

Got any spare power supplies lying around?

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Well, sort of. I could use the Power Supplies out of my slave systems (hardware boxer here), but I need to check that they have the juice needed to bot my main system (it's beefy). It wouldn't surprise me that something else could be the problem, though. I might have to stop by EVGA's community boards and see to it that this has or has not been dealt with there.

In the mean time, I'll look into my other Power supplies as resources to use. I'll make a Death Knight and play with them a bit in order to see if anything iffy happens while playing.

EDIT: I'm not sure it's a MB problem, but I could be wrong. My rational for this is that I was gone for several hours today between shutting the machine down and powering it up. When I got home, it was still messed up (as far the boot process is concerned). Perhaps I have missed something in my limited MB research that still allows this to be a MB problem. But like I said, this machine only booted up after I unplugged it totally and let it sit for a bit.

Actually, a friend just told me that's pretty much what happened when he had an old power supply on its last legs, so it could be either the MB or the PS.

Regardless, the easiest way to check is with another power supply. You don't even have to install the thing, just lay it on the open case and replace the power cables.

And if it doesn't have enough juice, take out the graphics card and unplug some drives.

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Originally Posted by 'mmcookies',index.php?page=Thread&postID=212087#po st212087

And if it doesn't have enough juice, take out the graphics card and unplug some drives.

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I did some investigation and it turns out I should be fine. The graphics card power is really optional, and I'm running an SLI board that requires power for the SLI stuff as well as to each video card. Those I don't need to install power to. Everything else is going to be fine.

Details forthcoming.

Are you running Vista? There are either CPU temp gadgets or a lot of high end boards have software utilities that could tell you if you are running hot. Otherwise get into your BIOS and look for temperature readings. If it is a manufactured system (like a Dell) it may have some diagnostic stuff that can run from BIOS. That could rule out memory and perhaps your PS (the fan at least). In my experience it sounds like a heat problem, but never rule the PS out.

It could be your memory also. If nothing else works try starting up with only 1 stick of memory at a time. If 1 stick is bad/going bad you could find it with trial and error. Also if they are real dusty memory sticks can overheat as well. You may or may not have a memory heat sensor on you MB.

Definitive Update:

It was the MoBo. Yesterday while playing, the main system crashed again with a nasty-sounding POP. I smelled a little smoke. Yeah. So I starting pulling things and trying to get the motherboard to POST (which it never did). I was doing all this with a good power supply, too. Turns out the one I had in the case is NOT defective. Anyhow...

I got down to just the memory and the processor in the MoBo. Pulled those two parts as well. Reset CMOS (for about the fifth time). Powered up. No POST. The MoBo is dead. The other parts look good. I'm on my way to pick up the new motherboard. We're going to see how it does.

It gets even funnier. The power supply was probably the culprit, so it has been replaced as well. But it turns out that when the whole system went, it took one of my drives in a mirror as well. It's something like this that makes me glad I mirrored in the first place. Drive blew up, data still exists. Yay me. Or not. Now, I have to replace the drive as well.

Damn.

Drives are very susceptible to power spikes. I recall a friend of mine in QA pulling the power to a drive one day without turning off the power to the unit and killing it probably much the same way. :P