Comp Blacked out weird...

Hi! im New to this website before i ask for help thank you everyone!

THis is my little brother's computer, when i came back from camping after 3 days, i tried to use his computer. When i went in to his room and bout to check out the internet. i touched the keyboard and all of the sudden the whole computer blacked out. The monitor was blacked and the system was turned off. I tried to turn the system on and it worked but for only 2 seconds and it closed back down. After that it wont turn on anymore. I changed a power supply and I was so glad I be able to see the cpu and vga fan moving UNTIL i notice the MOnitor was still BLACKED OUT!!! What has happen to it??? Also i notice when i try to close the comp, i would have to hold on to the power switch like the computer is frozen or some sort. Please help me out THank you!!!!!

I know:
p4 1.8ghz
256ram
gforce 4 ti
integ sound
cdrw/dvd combo
120gb hd


If there is any other question you want to know just post a reply or you could email me.. URL

Thank you,
Philip

Troubleshooting a Dead/Unbootable PC -
http://www.sysopt.com/articles/troubleshoot/index.html

CPU, mother-board, memory, for the moment.

check them out one by one.

You can check memory by attaching it to another PC. Also CPU, if possible. Then mother-board remains, most suspicious. Probably bios is gone.

1. Check and see all pluggs are secured.
2. see if the power supply cords are plugged in.
3. see if the power supply works