All new Hardware, Computer shuts down before posting BIOS

[Sniper_piper]

System Specs: AMD Athlon XP 3000 Barton core 400 FSB
Asus A7N8X-X Mobo
2x 256MB Corsair Value select
Saphire ATI Radeon 9600 128 MB
420 Watt PSU
80 GB Western Digital Caviar HD
Lite-on CD-RW
56Kb dial up Lucent-Win modem

So here's the problem. I built this computer a week ago for my mother using all brand new parts. I set the whole thing up, partitioned the HD to install windows XP, installed everything without a hitch, installed all the software after the first boot and shut the computer down for the night. I come back in the next day to set up user accounts I turned the power on, the system fans started up and ran for a few seconds then the system shuts down, no BIOS post or anything. I hit the power button again same result, again i hit it same result. I turn the toggle switch "off" on the psu, wait ten seconds then toggle it "on" I hit the power and the computer boots and runs normally. I shut down and try to turn the computer on again and i get the same powering off as i had experienced before. It seems that the only way to get the computer to power on normally after shutting down is to turn the toggle switch on the psu off wait for 10 secs then turn the system back on.


Things i have tried to fix this power problem:
1. Change out the power switch, I have tried two different switches same result.
2. Changed out the psu, same result.

I have read several similar post on different forums and have heard the following:
1. Virus, This is not the case because i had never even hooked the computer up to the internet.
2. Bad psu, already did it
3. Bad power switch, already did it.
4. Bad cpu, haven't done it but i think its doubtful since the computer works fine when it is on
5.Bad Mobo, I'm thinking this is most likely the problem, My friend told me that i may have a bad capacitor and that is causing the problem. This seems to be the most likely cause.

If anyone has any ideas please help. Thanks

 

[Merc14]

Have you treied breaking it down to thebasic components, CPU & HSF, 1 stick of RAM and video card, and then building it back up, one piece at a time, to see if some peripheral is causing the problem? Certainly sounds like a bad mobo though.

 

[.::Cyphon::.]

Has this issue been resolved yet?

I'm having exactly the same problem, my system specs are completely different but the result is the same except that when my system shuts down for the first time i cannot power back on no matter how long i leave it, i have to unplug the PSU (switch doesn't even make a difference)

 

[foozy]

Definately sounds like a bad motherboard, however, did you try overclocking at all? Are all the voltages set right? Are all your power connections secure? Replacing hardware should always be a last resort, especially since a good share of problems are caused by user error.

 

[.::Cyphon::.]

never tried overclocking, don't know if voltages are correct, all connections are secure, it's just a random error that can happen 20 times in one week, or not at all. Yesturday i had to leave the computer switched off for over an hour, then i tried it again and it has worked perfectly ever since. Once the computer boots i have no abnormal experiences whatsoever. Any idea on how to check voltages? What levels should they be?
I did do a search, it isn't applicable to my motherboard, but apparently some other MSI board models had faulty capacitors that could explain what i'm experiencing.

 

[am21]

I have a similar problem (Unresolved)

check this thread :
https://www.techspot.com/vb/topic69407.html

 

[.::Cyphon::.]

is it possible to get a build up on connections? i'm just imagining a spark plug on a car that has issues where there is a carbon build up and causes intermittent connection problems. perhaps all the switching on and off again caused something?