Allmost no sigh of life

[jmmen]

The only proof of life of my computer is the hdd light and the optical mouse light, besides that, nothing at all.  Already replace the power supply, and nothing.
My computer is as this:
Motherboard: ASRock K7VM3
CPU: Athlon XP 2000+
Memory: 512 MB DDR
Video: NVidia GeForce5200 128 MB
Win XP Pro
any light on this, will be appreciated.
T.I.A.
jmmen

[soybean]

Had you made any hardware changes, besides the power supply, just prior to this?  Do you get any beeps when you turn the power on?  Any signs of problems developing before this happened or was this just a sudden event?

Is that computer connected to a surge protector?  Any power surges just before this happened?  

Do you overclock that computer?  

[Raptor]

A little more information wouldn't hurt.

[Fed]

Try swapping monitors with a known good one or putting your monitor on a different computer to rule it out as a problem.

[GX1_Man]

And what make and size power supply is in there now? Was it new?

What happened prior to all of this?