Urgent Please Help

[rassler]

My computer was on and working when i went to bed last night, i woke up to it off and unable to turn it back on. I ruled out the power supply but have no idea what is the problem and how to fix it. If anyone could give me some possible solutions it would be great. Computer is 6 months old, i built it this past summer.
PCP&C 425 power supply
epox 8kda3j
AMD athlon64 3000+
1gig mushkin
seagate 160 gig sata
ATI 9800 pro
chaintech av710
liteon DVDRW
XP SP2

I do reglar cleaning with norton antivirus & AVG virus, ad-aware, spybot S&D, cclean, spyware sweeper. I downloaded some updates for XP last night, if that could have anything to do with it. Also was having trouble connecting my Dell Pocket DJ mp3 player last night, the PC would not recognize it. PLEASE HELP ME....and if u are willing to talk to me on the phone to help it would be great, as i am on a freinds computer. But please give me any advice u can on what to do. THANK YOU

[BokiOverclocker]

I had problem before like that on my first pc and end up to be a ON/OFF power switch on your case.
it was a broken spring. I replaced the switch and has bin ok since than.