Michael

I would first suspect overheating, though you have been inside the case 
and would have noticed excessive dust on the fans, heat sinks, and case 
filter, if the case has one. Also, you would have noticed if the CPU, 
video card and/or power supply fan was not working. Next I would 
consider the power supply. 300 watts is on the low end for what you have 
and a power supply can give out suddenly.

The 5 second delay on the case power button to turn off the computer is 
normal. I believe you can change it in the BIOS if you desire. As you 
found, the small green light on the motherboard is always on when the 
power supply is on (as differentiated from the computer being on). Lack 
of a beep normally indicates that the initial post is not completing.

Unless you are an electrical technician, checking out a power supply 
means replacing it with a known good power supply. Since the present 300 
Watts is on the low end, I would just purchase a new power supply with 
at least a 400 Watt rating. I have found NewEgg.com to have a good 
selection of power supplies at reasonable prices. They are a top rated 
retailer for service.

Once you replace the power supply, do not be surprised to find other 
components that might be bad. I have had two power supplies fry (smoky 
electrical smell) on me and take out with them a keyboard, mouse, two 
hard drives and one hard drive that had to have the OS reinstalled, and 
a CDRW-DVD combo drive. I hope this is not the case with you.

I hope this helps.

Tom Mayer

MICHAEL CAMPOBASS0 wrote:
> Hello ...
>   First time writing ... wonderful place for computer help.
>   I have a computer with a problem ... it wont turn on or more precisely wont stay on ... it shuts off (by itself) after 2 seconds or so ...
>   ---  Pentium 4
>   ---  1 Gig memory
>   ---  Running Win XP Home edition
>   ---  Mother Board is ASUS P4PE-X
>   ---  2 CD drivers (1 Burner and 1 DVD player)
>   ---  A floppy driver
>   ---  Connect to Internet using a DSL access
>   ---  ATX Case with 2 Cooling fans besides the CPU fan and PS fan
>   ---  300 watts Power supply
>   ---  McAfee A/V software
>   Here are the specifics:
>   The computer is well maintained ... Using Anty-spyware cleaners and Virus scans ... the computer is also updates as required.
>   I had turned it off for the night ... the next morning when I attempted to turn it on it seemed that all was ok ... heard the fans surge, the power-on light on the front of the case lighted normally ... but after 2 seconds the computer turns off (the power light remains on). I have to keep the the front power switch pushed for about 5 seconds to turn the light off so I can truy again. I dont hear any beeps.
>   Opened the case ... tried to power it ... noticed that all the fans operate also there is a green LED on the MOBO that is always on as long the Main switch on the back of the case is in the on postion. I disconnected one drive at the time and power it ... but no luck. Could it be a defective power supply? Or a dead HD? It was working fine the day before ... I dont know how to check it if I cant turn it on. Does anyone have a suggestion what could be the cause of this problems?. Any suggestion will be appreciated ... Thank you so much
>   Michael Campobasso
>    
>
>
> Michael
>
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