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Computer turns on for a split second, then shuts off.

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  • Power Supplies
  • Computer
  • Components
Last response: in Components
August 1, 2009 1:51:31 PM

ve had this computer in storage for almost a year now.

its a few years old.

specs:

intel 865 mobo
pentium D 2.8Ghz
2 gigs kingston
2 320GB seagate sata drives
audigy w/firewire
running xp sp3

it booted up fine, came into the login screen, i typed in my password, and no response, it took the password in the text field, and started to work, then froze.

****.

so i rebooted, thinking its been in storage for a while, maybe it just needs a clean format.

i boot, it logs into the screen again, i type the password, same issue.

i do a hard reset.

now this time, the bios posts, shows the winxp logo, then the computer just turns off. no power.

mind you, while it was on, i did bump it a little trying to move the box a little closer.

i push the power button, no response. i unplug the computer, turn the switch off from the back, then wait. i push the power, and for a split second, the power LED gets a jolt of power, and the fan in the back and the cpu fan START spinning but fail to continue.

i read some posts from others having similar issues, and many have mentioned that its the power supply. OR there's a short somewhere.

so i take the whole thing apart. bare board, video card, and ram, connected to the monitor to see if it'll post.

nothing. the same issue.

i take the video card out. now its just the mobo, ram, power, and monitor.

no response.

there was a case just like this out on the net where some guy had the exact same problem, and in 10 minutes, he comes back after he has unplugged the computer, and it worked.

no such luck in my case.

anyways. so i think its the power supply, i read online about a self test. taking a paper clip and connecting the green and a black from your connector that goes into the motherboard from the powersupply.

the computer seems to power, the hard drives spin, the cd rom works, but the
board doesnt get any power.

im stumped.

i searched the internet through and through....

More about : computer turns split shuts

August 4, 2009 9:15:35 AM

I suggest that you check all connections inside your computer. If everything checks out, I'm assuming it's your motherboard. You can try testing another power supply with your rig though.
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a c 144 ) Power supply
August 5, 2009 1:11:38 PM

Unfortunately, the old paperclip trick does not mean that much because you are testing the PSU under minimal load.

No system speaker? Do you have any way to listen for the beep codes as the system POST's?

Look here for more ideas:
http://www.tomshardware.co.uk/forum/page-261145_13_0.ht...
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Related resources
a b ) Power supply
August 5, 2009 2:44:43 PM

This sure sounds like a problem with a PSU or mobo that got older even when not in use. MAYBE it's the old leaky capacitor issue. A few years ago there was a rash of problems traced back to poor electrolytic capacitors that were good initially bu later developed too much internal leakage of power, leading to overheating and failure. The obvious external symptoms were one or more of these capacitors with tops that bulged up instead of being flat. These capacitors, for those who are unfamiliar, are little metal cylinders mounted on end on the printed circuit board, from ½" to 2" high, and ¼" to 1" diameter; they may be bare metal or may have plastic sleeves over them. The ones that developed faults and caused power to fail could be either inside the Power Supply Unit (you have to open it to see them clearly) or on the motherboard in a group near the CPU. The mobo ones are part of its voltage regulation system. I recently had to replace an Abit mobo that failed after 18 months, and it had 6 bulgy caps in the voltage regulator section. So I think (no proof yet) that was its problem.
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April 28, 2010 6:46:25 AM

I had the same issue with an older machine I had. Turned out the motherboard had popped a capacitor at some point.
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