Help with a homemade pc - no boot

Dear All,

I recently made a pc with the following config
AntecSX630
Ecs K7s5a
Duron 1200+Thermaltake copper shim+Thermaltake Volcano 6Cu
Leadtek winfastG2 Ti 64
Seagate baracuda 4
sblive+Asus dvd-rom

The heatsink was with a thermal pad and I used it like that .
I've also taken care of the shim not touching the copper bridges
of the cpu, and been careful when putting the heatsink.
I've checked everything, and I turned the power on.
During few seconds the fans (both from the case and the cpu)
where running, but suddenly everything was stopped ! (power off).
I turned the power on again, but nothing.
I was trying to investigate for "burn smell", but there were none.
I removed the heatsink, look at the cpu,
but again the core seemed undamaged and with no "scary brown color".
So I checked the stuff again,
did a cmos clean (put the jp4 on position 1-2 for few seconds),
and turned the power on again, and during 1ms the power led
is on and the fans run and then the power stop.
If I put the power again, nothing.
Does someone know what is wrong here ?
Could it be possible that the cpu is fried ?
If yes could it be a shim problem ? [misplaced in some way ?]
a thermal problem ?

Thanks for your help.
Cheers, Philippe.

the power supply seems to be overloaded, try removing the display DVD drive and the display card. if it beeps, both the board and the CPU are okay.

if ot doesnt, remove the shim and try. be careful putting the HSF on without the shim. if it works, put in the display card and boot.

now connect the DVD-drive, if it dowsnt boot, the power supply is inadequate, replace it with a better one.

girish

<font color=red>Nothing is fool-proof. Fools are Ingenious!</font color=red>

the power supply is the one provided with the Antec case
it's a 300W (atx 2.03), most likely made by Enermax.
The front panel power button is also correctly connected
to the mobo. The only thing that I haven't tested is to
boot without the vid card or to remove the shim.

after removing everything except mobo+psu+cpu, the
problem disappeared (it doesn't beep, but the power is not
turned off automatically).
Then adding the vid card, the problem re-appeared.
All other stuffs tested, so it really seems that it's the vid card
who is at the origin of the problem.
I just need now to test if the card is damaged or if it just
doesn't like the mobo.

thx for the inputs.

well it could be a problem with the mobo.
In fact now it's end of story, since I tested the mobo
with an other graphic card (an old Viper550) to see what happens,
and still no post, but
at least the fans were powered ...
and then the cpu died....
Thx to all for your help.