Computer lost power while running, now won't POST

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SenorBeef

Weaksauce
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May 20, 2008
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I had a running, fully functional computer when I accidentally pulled the power cord out from the PSU when I was untangling wires.

I plugged it back in, at which point the fans/lights all powered up (I didn't hit the power utton at this point, it just went on by itself), but there was no post. I held the power button down to shut it off, then turned it back on - the fans/lights all came on (including the loud graphics card fan at 100%), except the 200mm fan on top which seemed like it was struggling to move (movingly slightly back and forth).

So I turned it off and left it alone for a few minutes, then tried to turn the power on again. All lights/fans came on, including the 200mm fan for about 6 sceonds. Then the whole thing shut down for about 3 seconds, and then came back on again on its own and stayed on until I turned it off.

Since then, when I turn it on it either does the 6 seconds on, 3 seconds off, back on indefintiely thing, or it comes on and stays on the first time

When it does this there's no post beep or any sort of noise except the fans and I think the hard drives spin up but I'm not positive. The monitors won't even click out of standby mode.

Hardware is:
Corsair 520hx psu, antec 900 case, DFI tr2s dark (p35) motherboard, 8800 GTS video, 2x2gb ram, core 2 duo.

I have a spare computer, but it was built in 2004 so it's hard to swap hardware to test it out. I can't plug the old power supply into the new system because it doesn't have PCI-e power pins... I can't substitute the old card because it's AGP... and I don't have any PCI video cards sitting around.

Is it likely my PSU is fried? How would I go about testing that? If not, what component is likely giving me the problem? What steps should I take to isolate the problem or potentially fix it? Any ideas? Thanks.
 
Unplug all drives, clear/reset CMOS, and try again. If that doesn't work, you should do a barebones setup. Before you try that, though, try a spare PSU.
 
I plugged the PSU into an old system and the old system POSTed, so the PSU probably isn't fried. Although it's possible, since the old comp doesn't use as much power, or the 8 pin mb connector or the PCI-e connector so it's not a complete test.

I reduced the system to the minimum - 1 stick of ram, graphics cards, cpu, cpu fan, and it wouldn't post. The antec 900 doesn't have a speaker built in to the case so in order to hear the beep codes I got my old sonata case and plugged the SPEAKER cable into the new mb. There were no error beeps. I then removed the ram and GPU just to see if I could generate error beeps and there were none. But I'm not positive the old speaker works.

If it doesn't generate any beep codes, does that mean it's the motherboard? If the CPU were broken, would that issue a beep code?
 
Did you reset the BIOS/clear the CMOS with the jumper? I would think that if the motherboard wasn't damaged you should get beep codes for no RAM or CPU. Assuming the speaker works and is connected correctly.
 
Yeah, I cleared the CMOS a few times, no change. No beep codes either although I need to confirm that the speaker works by using it on a healthy computer.

If the CPU is fried in some way, do you actually get a beep code? Or would the CPU be necesary to get to that stage of the POST and therefore no CPU = no beeps?

I guess the MB or the PSU is fried .... it's not just a normal powerup with no beeps... about half the time it powers up for 6 seconds, then turns off for 3, then powers back up...... if it was some normal beep code like bad ram or bad CPU, it wouldn't do that, right?
 
make for darn sure you are performing the CMOS reset properly...

power down
unplug power supply
remove battery on motherboard
move jumper to reset position
go drink a beer
come back and put cmos jumper back to normal position
replace battery
reconnect power supply, power on
 
@ nobody_here
That should guaranty that the Bios is reset but it really isn't necessary to remove the battery unless you can't find the jumper. Can't hurt to try it though.

@SenorBeef
I can't say one way or the other if you get a beep for a bad/no processor condition. I've never tried to boot a motherboard with no processor or actually got that beep code on one of my PC's. I haven't worked on enough PC's to get into that situation. I have got beep codes for incorrect and or no RAM. If the documentation for your motherboard BIOS says you should get a code and you're not, my best guess is a bad motherboard and or power supply. If it was me I would borrow or buy another power supply to test with and go from there.
 
No, you typically don't get a beep error for a CPU problem, so the only way to know if your CPU is bad is to try it in another, known-working mobo. Its most likely your board or CPU, but out of the two, its typically the board. CPUs do go bad, but rarely before the board.
 
have an update.

So I disassembled and reassembled everything, including popping off the HSF and reseating the CPU. Then I ran the motherboard outside the case to ensure there wasn't a short. No change.

I also used the new PSU to power the old computer. The old computer has a 20 pin ATX and 4 pin 12v connector, whereas the new power supply has a 24 pin ATX connector and an 8 pin 12v. Still, it's backwards compatable because you can plug a 24 pin into a 20 pin, and the psu has a seperate 4 pin 12v connector. I booted into the bios, checked out the PC health section, and all the voltages were solid - 12v was 12.04, 5v was 4.94, etc.

Then I got a new motherboard (GA-EP45-UD3R) and it still doesn't work. The symptoms are a little bit different now, and I get some beep codes. But the errors and problems during boot are weirdly inconsistent.

First, the CPU fan, in the "cpu fan" socket, does not power up when the system powers up. It starts either 12 or 25 seconds after boot, depending on the hardware configuration. The GPU fan and PSU fans start right as the power switch is pushed.

And sometimes the system will instantly power off when I hit the power button, and sometimes it will require me to hold it for 5 seconds. What does it mean, that sometimes it's reaching different stages of booting?

If I run with nothing but PSU and CPU, no video, no ram, no HDs, etc, it powers on, continous short beeps at the same interval for 11 seconds (long enough for 8.5 beeps), then it powers off for 2 seconds. At which point it powers itself back on, runs for 11 seconds (with 8.5 beeps), and powers itself on, then restarts itself, etc.

"Continuous beeping" in the motherboard manual indicates a power failure.

If I plug the video card in (along with the PCI-E power connector) but still nothing else, it powers up, beeps 3 times, powers off, powers itself back up, beeps 3 times, repeat. The motherboard manual does not indicate what three short beeps means. I don't think it's the "continuous beeping" above, because it distinctly beeps 3 times, stops, and then powers off.

When I then stick in 1 ram stick in addition to the video card, it powered on for 5 seconds, powdered off, powered on again, and then roughly 15 seconds later gave off 1 long beep, and 2 short beeps (I think, it actually sounded like 1 long beep, and then 1 short beep where the volume dipped in the middle of the short beep, I think it's meant to be 2 beeps).

The manual says 1 long, 2 short beeps (What it probably is) is a gpu/monitor error. 1 long, 1 short (which it maybe is) is a memory or motherboard error. It then powered off as soon as I hit the power button.

I rebooted with the same hardware configuration and this time it didn't power off first, it just beeped at 15 seconds in. Even with the same configuration as last attempt, now it took 5 seconds of holding the power button to turn it off, it didn't do it instantly.

Then I tried removing the video card again and switching the ram to another slot. This time it powered up, 1 long 2 short beeps after about 8 seconds (which makes sense since the video card is missing), the CPU fan came on a few seconds after that at about 12 seconds, and it instnatly powered off when I hit the power button.

I put the video card back on, with the ram the same as above, and now after about 22 seconds it gave 1 long, 2 short beeps. 3 seconds later, at 25 seconds after power on, the CPU fan came on. It instantly powered off when I hit the button.

I then moved the ram to the third slot over, and it powered on - but no beeps this time. After 25 seconds, the CPU fan kicked on.

Whenever I had the video card in, I had it plugged into a monitor - and it never clicked out of standby mode.

I am now completely perplexed. So I came here hoping that someone would give me some idea, any idea, what's going on, or at least what I can try next.

To add: On a normal boot back when it worked, my video card would spin up to 100% fan when I hit the power button for about 2-3 seconds until it booted up its own bios and got its fan profile and lowered it to like 40%, so you'd hit the power button and get LOUD..2 seconds... quiet. Now it just stays on full blast, which I assume means the video card isn't getting to the point where it consults its bios. I'm not sure what that means, but I thought it was worth adding.
 
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Memory is especially sensitive to voltages, including voltage drops. It could have been fried, easily. I doubt it's the GPU, since it would be odd for the videocard to go like that. Not impossible, just unlikely.

It would be even more unlikely it's your CPU - because if it was you probably would not even get a beep!

In any case, try the memory in another PC and in different slot configurations. I also suggest checking out the GPU in another PC, just incase. And make sure you plug in the PCIE cable into the GPU or you WILL get the anoying BEEEEP coming from your MB speaker.
 
Unfortunately I don't have access to another computer that has DDR2 memory slots or PCI-E for that matter - the only thing I have access to are older athlon systems with DDR and AGP, which is what's making this so hard.
 
Yes as im reading this im going "OMG!" just a small loss of power can cause chaos! Hopfully you find out whats wrong cause life without my rig? its heartbreak!

Yes the best thing you can do is find a friend with same style computer (DDR2, same style CPU, PSU, and so on) and do a part by part swap and see what works in his computer and what dont
 
If Im reading correctly you have tested the PSU good, and purchased a new motherboard, and still having the problem?

If so, then you're down to CPU, VGA, and RAM. Does the new motherboard have onboard video? Use that instead if so and test. If not, then pick up a PCI-E 7600GS for like $25 at Microcenter if you have one nearby. Get a cheap stick of DDR2 RAM from a PC shop, like a used 512MB stick. Then see what you get.

The odds of it being your CPU seem slim to me, and as stated earlier, usually if your CPU is bad you get no POST beeps.
 
Have you asked around in here to see if someone lives close by you. You could just be a short drive away from your problem being fixed.
 
Standpoint said:
If Im reading correctly you have tested the PSU good, and purchased a new motherboard, and still having the problem?

If so, then you're down to CPU, VGA, and RAM. Does the new motherboard have onboard video? Use that instead if so and test. If not, then pick up a PCI-E 7600GS for like $25 at Microcenter if you have one nearby. Get a cheap stick of DDR2 RAM from a PC shop, like a used 512MB stick. Then see what you get.

The odds of it being your CPU seem slim to me, and as stated earlier, usually if your CPU is bad you get no POST beeps.
Click to expand...

The PSU was tested in an older computer with a 4 pin 12v and 20pin ATX and a lower power draw and no PCI-E card. So there's a chance that the PSU is good in that respect, but maybe the 8 pin 12v or PCI-E connector is screwed up and my test wouldn't show it.

My friend is mailing me his old pci-e card currently. If that doesn't work I'll post an update.

FLYINGDOG said:
Have you asked around in here to see if someone lives close by you. You could just be a short drive away from your problem being fixed.
Click to expand...

Nah, I didn't think to ask a stranger for a favor like that. I live in Las Vegas though, so if anyone wants to volunteer...
 
So, turns out it was the video card. A friend shipped me his old GF7950 and it's working, I'm on it now.

Which is weird, since the video card would be the last part I'd expect to fry with an electrical/sudden shutdown issue.

And my old motherboard, the DFI p35, won't give me any error codes whatsoever. When I knew everything worked except the video card, no beep. When I had the ram in the wrong spots, no beep. When I had no ram at all, no beep. The speaker/controller works because it gives 1 beep on POST, but that's it.

What a weird process to chase down a bum video card.
 
Weird indeed...
o.O.gif
 
Yeah sometimes you end up shaking your head and saying WTF? I was just working on a PC that had no hard drive and no RAM in it. The owner didn't know if it worked and it was given to her as is. I cleared the CMOS and powered it up and it wouldn't post, no beep and no video on the monitor. I noticed the hard drive led was on continuous so just for fun I put in an old drive I had laying around. It still didn't post and no video but I got 1 long beep. I took a stick of DDR out of my rig and put that in and it posted. I really didn't expect to have to put a hard drive in to get a post code. :confused:
 
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