Thanks for your reply.
THe card was working fine. I unplug everything and installed a new cooler. Then the card never worked again.
I know there may be sth wrong in the reassembly but there is not much to it. Just connecting the usb, 12v conectors, etc....
So 'yes' was working before, now after installing the cooler it does not. I isoleted everything (video card an motherboard and still does no seem to affect anything)
The Old card 8800gts works on 16x pcie slot so you may think the problem is the video card but how can it work on 8x pcie slot then?
any pointers will be helpul
ps. The motherboard has several beeps and fails to power on when the 460gtx is installed on the pcie 16x slot