PC fails to boot. Turns on briefly and turns off again.

[Mikeybob]

Hi guys,

My friend is here with me with his new comuter that he bought and built the other day. He had problems before getting it to boot after he built it, it didn't boot at all.

After he got his PC here, we tried to get it to work and were worried his mobo might have shorted as he didn't use any risers. We got a new mobo from PC World, but the computer just powers for a few seconds then off again.

Does anyone know what the problem might be? We're worried he's fried his CPU too. Some posts I've been digging around in suggest a PSU failure, but my friend insists the PSU worked fine before.

Thanks for your time :)

[edit]

We've sorted it. His case had some dodgy wiring :P. Sorry for the flase alarm guys :)

[Leonardo]

EDIT: whoa, I just reread the post.After he got his PC here, we tried to get it to work and were worried his mobo might have shorted as he didn't use any risers."Risers" - do you mean the hexagonal pieces that fit into the case side, to which the motherboard can be screwed in? Those are called standoffs. If you have not installed standoffs, your system will not boot, and will not ever boot. If this is the case, please disassemble the computer and start over. Use a standoff for each mounting hole in the motherboard.

If I have misunderstood your post, then please proceed to the next step below:


First, please tell us about the computer. Please use detail:

memory: brand, size
power supply unit: brand, rating
motherboard: brand, model number
video card: brand, model
any PCI devices?
CPU: brand, model
CPU heatsink: brand, model

[Mikeybob]

Risers, standoffs... horses for courses tbh.

[Leonardo]

OK, mini-poetry aside. Where are you now with the computer?

[majora2007]

I believe it is the power supply. I built a computer for my brother and I had the same problem, after 3-4 seconds it automaticly shut off. I just replaced the power supply and I was fine.

[Mikeybob]

Sorry to waste your time guys. I did edit the post soon after to inform anyone that we had found the problem. Thanks for the help all the same :)

[ak_cowboy]

I have the same problem with mine. I bought it a couple of years ago. I added a dvd burner and new hard drive. Last year it would just shut off while I was working on it. Someone told me that the stock 350w psu was not enough for everything that was on it. I bought a 600w psu and installed it. Every 10 or so times when I turn it on, it will turn on for about 3 seconds then turn off and won't turn on again unless I unplug the cord from the psu wait about 5 seconds and plug it back in. I have just dealt with it but now I am tired of dealing with it. What is the chance of getting a bad psu new out of the box. Any other ideas. Thanks

AMD 2400
1.gig mem
80 gig hd
usb 2.0 upgrade
3.5 floppy..what is this for..lol

[profdlp]

Please see ak_cowboy's thread over here (http://www.short-media.com/forum/showthread.php?t=54872) if you have any suggestions. :)

[Benzinsane]

EDIT: whoa, I just reread the post."Risers" - do you mean the hexagonal pieces that fit into the case side, to which the motherboard can be screwed in? Those are called standoffs. If you have not installed standoffs, your system will not boot, and will not ever boot. If this is the case, please disassemble the computer and start over. Use a standoff for each mounting hole in the motherboard.

I'm having the same problem. I turn on my pc, i can see the fans and all the led's turn on, then everything goes off immediately. I have a Micro board, so I don't use all the Standoffs on my Antec 900 Case, but the only wholes that I screwed in to were the ones with standoffs in them. Could this be my problem? I mean, it supports micro boards, but I don't know if I need all the wholes in the motherboard screwed in or not.