Computer Powers up for 3 seconds then shuts off

[mark2talyho]

I recently rebuilt everything on my computer except the optical and hard drives
so today i go to power it up for the first time
and it goes on for 3 seconds and then it shuts off
what do i need to do


SPECS:

AMD Athlon 64-bit X2
Asus ATX Motherboard
RaidMax 600Watt Power supply
1GB RAM
120GB HD
60GB HD
DVD-ROM
DVD-RW
Floppy
USB 2.0
Radeon X1650
Sound Blaster X-Fi

 

[Zelvek]

Is anything coming up on the screen? Check that all your components are seated correctly (unplug everything in the case then plug it back in).

 

[GalvanizedYankee]

Is the Raidmax PSU DOA?

 

[jackschmittusa]

No rpm signal from the hsf will do that.

 

[Laputa]

Or must forgot to connect something....

 

[RebateMonger]

Perhaps the 12V cable (4-pin) to the motherboard?