System not starting up, no beeps

[DrBiggles]

I wasn't really certain what forum to stick this in, but it is a home-built system so I guess this works.
All of a sudden my system isn't booting.. I power it up but there's no video output and the bios doesnt do it's usual "beep"... and no error beeps, either. The hard drive light flickers like it's reading, though. The system is showing it's age:

P4 3.2ghz cpu
2gb ddr 400 memory
ASUS P4C800-E Deluxe motherboard
ASUS Radeon 9800XT 256mb gfx card
400W PSU

The first thing I checked was the video card and noticed that the last fan had died (it had two, one died long ago and it ran just fine), so I assumed this to be the problem and went and picked up a Radeon HD 2600 Pro. However, the system STILL wont boot, so apparently that wasn't the problem (and apparently the 9800XT was running for a while without any working fans! Just the side fans of the case blowing on it... that's what I get for not using the fan monitoring software).

Frustrated, I tried booting with one stick of ram at a time in the first memory slot (this kinda memory can be fussy about where you stick it, I'm told, so maybe I'm putting it in the wrong slot?). Still nothing.

So now I'm stumped. Any ideas as to what the cause could be?

 

[akhilles]

Try another psu.

 

[ethel]

Can you hear the hard drive accessing as though it's booting up Windows?

 

[hairycat101]

Try another psu.

Exactly. I have had this happen a few times. It is probably the power supply or the connections from the power supply not being seated well enough. Let us know if this works. Also, might as well clear the Cmos. Let us know if this helps. Good luck.