Sign in with
Sign up | Sign in
Your question
Solved

System won't boot

Last response: in Systems
Share
May 9, 2012 10:17:14 PM

Hello,
I have an Asus P5B-E mobo in an Antec Sonata ATX case with an Antec 450W SmartPower power supply. System worked great for several years then suddenly failed to boot. When I turn the PS on, I see the green light on the mobo light up. When I press the power switch on the front of the case, the PS's internal fan spins, but not the external fan (as designed, according to the Antec Owner Manual). The video card fan also spins. Problem is the fans whir up then down, about twice per second, and the system does not boot. It continues this way until I turn off the PS. No speaker beeps. Removed video card; same behavior. Removed all optical and HD drives; same behavior. Removed RAM; same behavior. Removed CMOS battery for 15 seconds and replaced; same behavior. Don't know what to try next. Any thoughts?
Thanks,
Tom

More about : system boot

Best solution

May 10, 2012 1:16:28 AM

Disconnect all components except keyboard, reseat the 24pin motherboard power connector...attempt to start and see if any beeps...also you can try this with the power supply itself removed...

To perform the steps below...IMPORTANT...disconnect EVERYTHING from the psu...and...REMOVE IT FROM THE CASE FIRST.

you can jumper the green wire on the 24pin connector to a black wire..this allows the psu to start without a switch...read here to see how.

http://www.gideontech.com/content/articles/196/1

that will allow you to see if the psu itself has completely failed...then if you have a volt meter....check for power in the pins to see if 12v +and - , 3.3v and 5v +and- have power on them...if not...the psu has died...if it starts and produces power..you have a piece of hardware that has gone bad...could be the motherboard itself, or any one of your peripheals that has died and is "dead shorted" killing the psu through the protection circuitry.

I own a psu tester (they are about $13) so I just plug in the 24pin and check for green lights on all voltages...

You need to see if the psu will fire up...if it does...and you can't check the voltages...you can plug in each peripheal one at a time to see which one kills it or if there's no power on the plugs you have been using.

Make sure the components are mounted in the case...but before plugging any of them in...once you determine if the psu will fire up outside the case...plug the 24pin into the motherboard and attempt to start the psu...if it starts with nothing else in the case...the motherboard is "probably" ok...if it doesn't start outside the case the psu's bad...if it does but won't start once plugged into the motherboard socket...the motherboard is bad.

This is the easiest way I know of checking your components, motherboard, and your psu.

Good Luck and be careful to not leave anything attached when jumpering the psu to start it by itself..in case it's putting out no power or bad power...the psu has built in circuitry for protection and so does the motherboard.
Share
May 10, 2012 4:46:31 PM

tekman42 said:
Disconnect all components except keyboard, reseat the 24pin motherboard power connector...attempt to start and see if any beeps...also you can try this with the power supply itself removed...

To perform the steps below...IMPORTANT...disconnect EVERYTHING from the psu...and...REMOVE IT FROM THE CASE FIRST.

you can jumper the green wire on the 24pin connector to a black wire..this allows the psu to start without a switch...read here to see how.

http://www.gideontech.com/content/articles/196/1

that will allow you to see if the psu itself has completely failed...then if you have a volt meter....check for power in the pins to see if 12v +and - , 3.3v and 5v +and- have power on them...if not...the psu has died...if it starts and produces power..you have a piece of hardware that has gone bad...could be the motherboard itself, or any one of your peripheals that has died and is "dead shorted" killing the psu through the protection circuitry.

I own a psu tester (they are about $13) so I just plug in the 24pin and check for green lights on all voltages...

You need to see if the psu will fire up...if it does...and you can't check the voltages...you can plug in each peripheal one at a time to see which one kills it or if there's no power on the plugs you have been using.

Make sure the components are mounted in the case...but before plugging any of them in...once you determine if the psu will fire up outside the case...plug the 24pin into the motherboard and attempt to start the psu...if it starts with nothing else in the case...the motherboard is "probably" ok...if it doesn't start outside the case the psu's bad...if it does but won't start once plugged into the motherboard socket...the motherboard is bad.

This is the easiest way I know of checking your components, motherboard, and your psu.

Good Luck and be careful to not leave anything attached when jumpering the psu to start it by itself..in case it's putting out no power or bad power...the psu has built in circuitry for protection and so does the motherboard.


Thank you very much. I'll run these tests this evening and report back.
m
0
l
Related resources
May 11, 2012 9:18:31 PM

Llike it's the mobo. Thanks for your help!

Tom
m
0
l
May 19, 2012 1:57:17 PM

Best answer selected by taroussell.
m
0
l
May 21, 2012 3:14:43 AM

My pleasure...glad to be of help!:) 
m
0
l
!