Computer turns on but nothing happens

[Mello_1]

I was using my computer, but after one hour the monitor turned to black. Every time that i try to shut it down it wont (pressing the power button doesn't works) and i took off the 2 RAMS and it did no sound as it usually does, could you guys tell me if this is a motherboard problem, this is a 'brand' new computer(one year) and i'm really pissed off that it's already broke.

Also, if it is a problem with the motherboard, can i fix it myself?

My motherboard: Asus M5A78L-M LX/BR

 

[Hellfire13]

cud be anything...the issue need to be narrowed down...
wat components/hardwares are attached currently???
r u getting post???

 

[smorizio]

see if someone has a known good power supply that first step on debug is known the power supply is good.