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Old 01-28-2007, 09:52 PM
javaboju@gmail.com
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Default Re: PC Won't Power On

Hi Rod,

I have the exact same symptons as Alex, with the exception of not
having had the computer boot up at all.
I tried removing the motherboard from the case, but I am still unable
to power up.
All I have in the board is the CPU and the RAM.
It is the same ABIT NF8-v2 Motherboard, my second one, I RMA'ed the
first one for the same problem.
The power supply is an ANTEC SP500 model, brand new.

The first board powered up but wouldn't display anything on my
monitor, so, thinking it was the video card, I removed the card and
reseated it, then it wouldn't power up at all.

So I RMAed the board back to ABIT, but when I put the new one in it
won't power up at all, with just the CPU and RAM.

Comes on for about a second then powers down.

Could this be an issue with the power supply?

Thanks for any help...

Bob



Rod Speed wrote:
> AlexBohner <alexbohner@yahoo.com> wrote
>
> > I followed your steps exactly, and while I can't confirm
> > the original problem, everything started working perfectly
> > once I pulled the motherboard out of the case!

>
> If you didnt find a loose screw etc in the case after you
> removed the motherboard, thats usually due to the use
> of metal hex studs to mount the motherboard, with a
> a motherboard that doesnt have proper solder lands
> around the mounting holes. The top of the metal stud
> can cut thru the solder mask and short at that point.
>
> The fix is to use plastic standoffs with the holes that dont
> have a proper large solder land around the mounting hole.
>
> > Thanks for taking the time to write up such detailed
> > troubleshooting steps. Not only did it help resolve this
> > problem, but the general understanding it provided will
> > undoubtledly assist in future troubleshooting as well.

>
> Thanks for the washup, too rare in my opinion.
>
> > This is a great thread to keep handy!

>
> > Many thanks!
> > Alex

>
> You're welcome.
>
>
> > Rod Speed wrote:
> >> AlexBohner <alexbohner@yahoo.com> wrote
> >>
> >>> I have run into a problem which I just can't figure out,
> >>> hopefully someone out there has an easy answer for me.
> >>
> >>> Several months ago I built an ABit/Sempron system, everything
> >>> was working fine until last night when I pulled a 1394 PCI card
> >>> from the last slot on the board, now it won't power on. Correction,
> >>> when I attempt to power on the fans start spinning for a fraction
> >>> of a second, then everything just shuts off.
> >>
> >> Such a short run of the fans usually means that the power
> >> supply is seeing a load it doesnt like when it starts.
> >>
> >>> Immediately pressing the power button again does nothing,
> >>
> >> Because the power supply has decided that its seeing an unacceptible
> >> load.
> >>
> >>> but resetting the power on the power supply allows me
> >>> to press the front power again, but with the same results.
> >>
> >>> I have reseated everything in the box, cleared the CMOS,
> >>> even tried reinserting the 1394 card, all to no avail. Does
> >>> anyone have any idea what may be happening here?
> >>
> >> The three main possibilitys are that you have removed something
> >> in the process of getting the 1394 card out and didnt replace it
> >> where it was originally, you've got a short to case now that was
> >> produced by the process of removing the 1394 card, and that the
> >> power supply or motherboard has just chosen to fail now and that
> >> the 1394 card removal is a coincidence.
> >>
> >> If you didnt do anything except remove the 1394 card, didnt
> >> unplug anything so you could remove it, a short is most likely.
> >> You sure you didnt drop a screw from the 1394 card bracket
> >> and didnt bother to try to get it out etc ? If you cant easily try
> >> a different power supply, it would be worth running the
> >> motherboard loose on the desktop. Thats the best test of a short
> >> to case and you might find a loose screw in the process that has
> >> been there all this time and got moved by the 1394 card removal etc.
> >>
> >> If running it loose on the desktop doesnt help, try unplugging
> >> everything you can from the motherboard excep the cpu.
> >> See if it will power up in that state and beep complaining
> >> about the lack of ram etc.
> >>
> >> If that doesnt help, it would be best to try another power supply
> >> even if you have to buy one if there is no evidence of bad caps
> >> on the motherboard. The caps are the usually blue or black
> >> plastic covered post like things that stick up vertically from
> >> the motherboard surface. The tops should be flat and if any have
> >> bulged or have leaked, thats a bad cap and likely the problem.
> >>
> >> Its very unlikely to be a dead cpu if you havent overclocked it
> >> and even then, that usually doesnt produce those symptoms.
> >>
> >>> Any thoughts or suggestions to point me in
> >>> the right direction will be greatly appreciated.
> >>
> >>> Machine Specs:
> >>> ABIT NF8-v2 Motherboard
> >>> AMD Sempron 64 3400+ Palermo 2.0GHz
> >>> 2x 1GB OCZ PC3200 Platinum Edition RAM (2 GB total)
> >>> Radeon 9800 SE 128MB Video Card
> >>> 100GB Seagate 7200rpm PATA Hard Disk
> >>> Thermaltake TR2-430W Power Supply



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