The old computer starts for 2 seconds then turn off problem

[LunisticTweak]

built my computer over 4 years ago, woke up one day and my computer would only turn on for a couple seconds before shutting down. stripped it down to:

MoBo: Soyo Dragon Plus 2 (ATX, 478 socket)
PSU: 350w w/ X-dreamer case
CPU: 2.6Ghz Intel P4

still had same problem. replaced PSU w/ 400w, same problem, replaced CPU w/ 2.4Ghz P4, same problem. thought it was a bad CPU because when start it up w/o the 4 pin connecter plugged into the motherboard, it runs the fans w/o powering down.

what am i missing?

appreciate your time.

 

[howard_hopkinso]

Hello and welcome to Techspot.

Providing you used fresh thermal paste and the heatsink is properly attached, I suspect a faulty cpu.

Regards Howard :wave::wave:

 

[LunisticTweak]

i suspected as well, but replaced it w/ new 2.4 Ghz P4 processor and thermaltake heatsink w/ paste, and no luck.

 

[kristouk21]

HI

does it actually get past the POST??

i had similar prob with 1 of my older machines... mine happend to be faulty RAM... 1 of the chips had failed.. caused all sort of problems..

 

[LunisticTweak]

no it doesn't get past POST. i don't hear any beeps from MoBo

no ram currently installed.

 

[kristouk21]

have u put ram into the machine an tried it ?
what does it do?
Have u ever tried to overclock the CPU????

if u have and the chip cant support the speed that can result in system restart.. the screen ctays black.. if the board thinks the chip is going to run dangeroulsy hot it will shut down the machine or restart..

failing that check over the board just incase there is any other chips which u can phisically remove by clipping them off the board.. there may well be 1 chip that may have come loose.

 

[LunisticTweak]

just installed a stick of ram and tried powering it on. powered up for a couple seconds, then everything powered down as before. still no beeps, just the green LED light on MoBo remains on.

 

[kristouk21]

have u ever tried to overclock the chip ?

 

[howard_hopkinso]

Looks like you`ve tried all the right things. Given the situation, I suspect a faulty mobo.

Regards Howard

 

[LunisticTweak]

sorry, should have answered in previous post.

no i haven't tried any overclocking.

 

[kristouk21]

possible then that your board may have let u down then my friend....

 

[LunisticTweak]

to howard,

so even though it will run w/o 4 pin CPU power connector, the mobo is probably bad.

thanks

 

[howard_hopkinso]

Yes, I think that`s entirely possible.

Regards Howard

 

[9Nails]

I'd second the shot-in-the-dark at a bad mobo too. Given the computer's age, and description of the problem, I'd specifically suspect a bad capacitor.

You might creep around this site for specifics on bad capacitors: http://www.badcaps.net/

 

[LunisticTweak]

afraid that was going to end up being the case. but alright, thanks guys, appreciate your time.

 

[kristouk21]

no worries.. anythime good luck