Computer Dead--is it the Power Supply?

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Oct 7, 2005
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46
I think my PSU may have died. While gaming the image on my monitor froze up and after about 5 seconds I concluded that the rig had crashed, so I shut it down manually. The PC still had power since the HDD light was on. I came back about 15 minutes later and it would not even attempt to post as though it had no power at all. I took the side panel off and the PSU felt hot or at least very warm (but maybe that would be normal). However, I did see a mobo light flicker whenever I pressed the power button. I know it isn't the main HD because I moved that to another computer an it works. I attempted to start it several times over the next couple hours, but no dice.

This failure occurred without warning; the computer has been fine for the past several months.

Does it sound like the power supply? Will PSU's suddenly croak without warning--without having caused any performance problems in the recent past? Could the mobo or CPU have suddenly died?

In the past, perhaps once every 6 months the computer would freeze and then would not restart immediately, but would start again after being down for a minute. Could it have a problem with overheating? (I also discovered that all three intake fans were caked with dust.)

The suspected dead power supply is: Fortron 550W EPS

I don't own a PSU tester. Would it be a good idea to test this by taking a PSU from an old computer, connecting it to the mobo, and then seeing if the PSU fan and mobo fans turn on?

<EDIT> I just tried it again and it started up! 27 hours after it went down. I'm pretty sure I tried starting it up earlier today. Any ideas? Does it sound like the PSU?
 
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If the PSU died it would likely not power on with no lights anywhere at all.

It could be a lot of things, but it's probably heat related. But that can be heat on the CPU, GPU, RAM, mobo chipset....

If it dies again hook up a known good PSU right away and test if possible.
 
(I also discovered that all three intake fans were caked with dust.)
Yes it sounds like the PSU & yes it is a good idea try a PSU that you know works to verify. Assuming that we are all correct, what are your system specs so we can recommend a new PSU?

With your "edit - update", the world changes. Clean it up, check to be sure that all of the fans are working properly & Good Luck!
 
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If the PSU "failed" it's likely it would've completely shut down. Since it fired up once the rig cooled down, we can assume that it overheated, but that would've caused the PSU to shut down as well.

Given that the PC froze, I would look at some other aspect of the PC overheating. Northbridge, Southbridge, GPU, etc. Something that wouldn't necessarily shut down the PC when overheated.
 
If the PSU "failed" it's likely it would've completely shut down.

Agreed, most likely it would have been instant off for a PSU failure.

This problem sounds like a GPU overheat or less likely a CPU overheat. Could also be the chipset on the motherboard overheating. Check your fans and also monitor the temp of your GPU, CPU and motherboard (if possible).
 
I wouldn't be surprised if overheating caused or contributed to the initial problem, but that wouldn't explain why it intermittently struggles to boot up even when it hasn't been used for hours and is ice cold. Here's more data:

The computer ran fine for about an hour-and-a-half last night and even ran an FPS game for half-an-hour. So the computer itself seems to be fine, at least the RAM and CPU. Perhaps the mobo has some sort of issue relating to start ups.

I came to start it up again today and it wouldn't start! I keep pressing the power button and nothing happened. I just happened to be pressing the power button while I was pulling the power cord out of the PSU when the yellow HD light came on. I plugged it back in and it started right up and froze when Windows loaded. I pressed the power button to shut it down and it booted up fine on the next try (typing on it now).

Could this be a bad connection between the power cord and the PSU or a faulty power cord? I've never heard of one going bad. Does this eliminate the mobo as a culprit? It seems like the CPU and RAM definitely aren't the problem.
 
Assuming that we are all correct, what are your system specs so we can recommend a new PSU?

Socket 939 Athlon 4400 (dual core, 10% overclocked from 2.2 to 2.42 GhZ at 1.5v)
2 optical drives (rarely used)
2 ATA 7200 RPM hard drives
3.5 floppy (rarely used, not currently connected)
Six 80mm case fans
One 92mm fan (CPU heatsink)
(single) BFG 8800 GT OC (which has a crappy, standard HSF).

The potentially problematic PSU is: Fortron 550W EPS
 
Socket 939 Athlon 4400 (dual core, 10% overclocked from 2.2 to 2.42 GhZ at 1.5v)
2 optical drives (rarely used)
2 ATA 7200 RPM hard drives
3.5 floppy (rarely used, not currently connected)
Six 80mm case fans
One 92mm fan (CPU heatsink)
(single) BFG 8800 GT OC (which has a crappy, standard HSF).

The potentially problematic PSU is: Fortron 550W EPS
Are you still under warranty?
 
I built the rig in late January 2006 and have probably owned the power supply since sometime in late 2005. I guess I'd be covered if it had a 5 year warranty. The Newegg page says 1 year warranty for the PSU, but that doesn't mean it wasn't 5 years when I bought it.
 
I built the rig in late January 2006 and have probably owned the power supply since sometime in late 2005. I guess I'd be covered if it had a 5 year warranty. The Newegg page says 1 year warranty for the PSU, but that doesn't mean it wasn't 5 years when I bought it.
Write down the serial number and call Antec.
 
The sporadic problems points to a failing capacitor. It could be on the motherboard.

However, I also had a few FSP psu's go bad.

Because the computer is old, I would suggest it's time to upgrade!
 
The sporadic problems points to a failing capacitor. It could be on the motherboard.

However, I also had a few FSP psu's go bad.

Because the computer is old, I would suggest it's time to upgrade!

Oh bugger. I can live with the start-up problem if it doesn't affect anything else or get much worse. If I can ever find a (middle class) job then I'll be able to upgrade to a quad or six-core, but sadly I'm part of the legion of unemployed.
 
Check your northbridge power connector. That could be the issue. A Lot of times, if you see the motherboard blink on but it won't make it to post, the Northbridge isn't getting the power it needs. I found this out while changing a CPU cooler and plugged in the wrong part of the extension cable.

If this is the case, perhaps your PSU isn't providing power to the Northbridge (and replacing a PSU is cheaper than a Mobo+Processor).
 
Check your northbridge power connector. That could be the issue. A Lot of times, if you see the motherboard blink on but it won't make it to post, the Northbridge isn't getting the power it needs. I found this out while changing a CPU cooler and plugged in the wrong part of the extension cable.

If this is the case, perhaps your PSU isn't providing power to the Northbridge (and replacing a PSU is cheaper than a Mobo+Processor).
The northbridge does not have a dedicated power connector. If you're talking about the 8-pin EPS12V connector, that is for the CPU.
 
If you have some compressed air, trying cleaning out the power supply and see if that helps. It seems like the power supply is overheating on you.
 
Everything has been fine since mid-July now. My normal routine is to leave the power cord in when I shut down at night, and then when I come back in the morning, I normally have to unplug the power cord, hold the start button for a few seconds, and plug the cord back in and it starts right up without any problem.

But now it seems to be dead again.

I've been out of town for the past two weeks and left the power cord unplugged while I was away. Now I can't get it to start up again and it shows no signs of life. I'm going to leave the power cord in and try to start it every couple hours.

Does this sound like I have a PSU problem or a Mobo problem?
 
i have been reading about this for 4 months over at anandtech. still debating over pulling the trigger on that ocz psu for $22 in long green or what?
 
i have been reading about this for 4 months over at anandtech. still debating over pulling the trigger on that ocz psu for $22 in long green or what?
What $22 OCZ PSU are you talking about?
 
a stealthxstream 500 something that was on sale back in july when he first posted this at AT.
 
a stealthxstream 500 something that was on sale back in july when he first posted this at AT.

For an office type PC (basically dual core and onboard GPU), for $22, the StealthXStream 500W is an ok choice.
 
Well, I really hadn't had a problem since mid-July. The computer has reliably booted up using the "unplug the cord, hold reset for a couple seconds, plug it back in and start" trick. The computer ran just fine for hours and hours of heavy-duty gaming after doing that. So, I didn't have a need to replace the PSU.

Then I left town for two weeks and left the PSU unplugged. When I returned yesterday it was completely dead and the unplug-reset-plug-start trick no longer works. I'm assuming that the PSU is the problem, otherwise I might end up doing a little system building soon.

Right now I'm looking at an OCZ StealthXStream 600w for $40 AR at my local Microcenter. It's supposed to be pretty decent for the price. Hoping to pick up the Corsair 850 TX for $90 (rumored to be on clearance at Best Buy) if I can find one locally.
 
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Problem solved!

It looks like it was the power supply. I just bought a Corsair 850 TX for $90 at Best Buy. (It's a clearance special, YMMV, model CMPSU850TX SKU 9358287.)

This PSU has a monstrous amount of cables. Fortunately I was able to zip tie the ones I won't be using and fold them up above the power supply. An 850w enthusiast PSU is probably overkill; I merely have a single 8800 GT and an overclocked Socket 939 Athlon 4400 (10% overclock). I'm still a computer noob and it was a little nerve wracking having to swap out the PSUs in a tightly-packed tower. I was afraid that after all of that work I'd find out that the PSU was not the problem.

Only problem is, I don't feel any air being pushed out the back of the PSU. Is it safe to assume that the fan is controlled by a thermocouple and will turn on when it gets hot? Should the fan blow air into the computer, sucking it out from the back of the PSU, or should it suck air into the PSU from the computer, pushing it out the back?
 
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The fan is indeed temperature-controlled. It will run when necessary. And the fan is an exhaust, so it sucks in air from the case(or underneath the case if it's bottom-mounted above an intake grill) and blows it out the back.
 
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