Computer with HIS HD 3850 IceQ 3 Turbo cannot boot Help!!!

Hi guys,

I'll be straight to the point.

My specs:-

AMD X-2 2.51 Ghz
Kingston PC667 2Gb RAM
160GB W.Digital H/D
Abit NF-M2PV Mobo
2 12V Casing Fan
450 W Max PSU
HIS HD 3850 IceQ Turbo 512Mb DDR3

This setup was working fine until last weekend, the screen turned black while i was going online. Tried restarting. Then, when I pushed the power button, the power stays for only 1 sec and after that the power light didnt even blink and wont start again.

Unplugging the power cable and re-plug again wont work.
There was no sound detectable. Heat in the casing was normal.

But, when I removed the graphic, and used the built-in graphic card, the computer works fine.

Can anyone help me with this? I dunno whether its my PSU or my graphic card. How would you know if the graphic card is fried?

(Please forgive my bad english)

Tried the g/c on another pc but still wont work. Same problem. The power light blinked for only 1sec and just died out. There were no sounds and it just died suddenly during a non-intensive session.

It was working perfectly fine before. Any ideas?

OK. Thnks for ideas. Anyway, my friend told me that card could have been fried....there goes my 399...sigh....