Compputer Won't Start

[PWNettle]

A PC I built a little over 2 years ago (for my mom) is now failing to post or boot. The computer is a simple/budget build that's run flawlessly for over 2 years now, used for email, web surfing, word processing, super light gaming.

Yesterday apparently the computer would post up with no error messages and boot normally into windows, and could be used normally (email/browsering) for about 5 minutes, when it would then spontaneously shut off (not shut down, just shut off completely as if power was cut).

I had them (mom/bro) open the case, clean out the dust (with canned air), and disconnect everything except power to see if all fans were running. Once they did that the computer wouldn't post or boot at all.

I got to personally mess with the PC this morning. Checked all connections, reseated a few, etc. The computer still won't boot.

If I disconnect all power, reconnect it, then flick the master power on the back of the PC, the fans will spin very briefly then stop.

If I press the power button, most of the time nothing will happen. On a few attempts the fans would spin and it would look like the PC was going to fire up for a few seconds, then poof it would stop.

With the master switch on, the power LED on the front of the computer is blinking - but that's the only indicator of power beyond brief fan spinning as described.


So, any thoughts?


I've been reading around and as usual, there's so many things it could be it's hard to find a definitive answer. I don't have extra parts available to swap out and isolate, which sucks. After seeing the PC, I read how to test the 20 pin and power switch - so I could possibly narrow it down that way. But I'm hoping the symptoms I've described help one of the experts here come up with something.

The system:
Antec Solution SLK1650B Black Steel ATX Mini Tower Computer Case 350W Power Supply
MSI K8N Neo-V Socket 754 NVIDIA nForce3 250 ATX AMD Motherboard
CHAINTECH LA-FX20-H GeForce FX5200 128MB DDR AGP 4X/8X Low Profile Video Card
CORSAIR ValueSelect 512MB 184-Pin DDR SDRAM DDR 400 (PC 3200)
LITE-ON Combo Drive Black IDE Model SOHC-5236V
Maxtor DiamondMax 10 6L080M0 80GB 7200 RPM Serial ATA150 Hard Drive
AMD Athlon 64 3000+ Newcastle 2.0GHz Socket 754 Processor Model ADA3000BOX
SAMSUNG Black 1.44MB 3.5" Internal Floppy Drive
Microsoft Windows XP HOME Edition with Service Pack 2

She's got some kind of deskjet (hp I think), a scanner, speakers, and an LCD monitor too - but I don't know the specifics of those as I didn't order them and don't think they're related to the problem anyways.

 

[dantonic]

I had a very similar problem.
My computer used to have power run through it, I would see the mobo display lighting up. But if I tried to turn it on it would power up the fans for a split second, then nothing...

If I let it stay with the power switch on for a few minutes, and then tried to turn it on it would sometimes power on, as if it needed to charge up first.

I found out with help from the forums, and by opening up the PSU itself that I had bad capacitors in the PSU.

They were leaking/exploded etc. it was a mess.

I replaced the PSU and everything has been great since. stable clean power, no problems, turns on everytime.

Check out this site: badcaps.com

It really sounds like the PSU to me.

Also examine the Capacitors on your Motherboard before you open your PSU.. if you notice that those are exploded, leaking or swelled it might be your mobo, and you probably will have to replace it.

 

[Ultralight]

When I look at your list the first thing that jumps out at me is your Antec 350w psu. They have been known to have bad caps at certain build times by CWT. Even if it isn't bad caps, I would want to test if the power is being distributed as needed.

Do you know anyone who can test it for you?

Can you hook up another power supply to see if it the PC will boot-up and load?

 

[PWNettle]

The mother board looked fine - I gave it a good inspection looking for loose wires/anything out of the ordinary.

I could get a PSU to test with but if the general feeling is that it's the PSU I'm tempted to just go with that thought. I'm also hoping it's the PSU and not the mobo as I think it'd be more painful to find another socket 754 board!

Thanks or the replies so far!

 

[goatjc]

I hope it's not the mobo too. . .but I had the exact same problem w/ my mobo, even w/ a new power supply. I opened up the case, powered it on, and BAM, a chip literally blew up in my face.

 

[dantonic]

My faulty PSU was an Antec Neo 480w.... and it crapped all over itself. That wasnt my first bad experience with antec PSUs either.
I am a firm believer that Antec makes absolute "crap" Therefore if I were you I would change the PSU regardless just on principle and safety for the rest of your hardware.

Get a seasonic, Fortron FSp, enermax... the good ones

 

[stevty2889]

Another vote for the power supply, one of my 450w Antec's died on me recently, barely over a year old.