My graphics card has stopped outputting. I powered on and the gcard did its usual high rev fan start-up, stopped and then repeated a couple of times. I can't get a video output from the card at all. If I unplug the two 4-pin external power connectors from it the green led on the side of the card changes to red. I tried running the card without the external power connectors to no avail and also tried unplugging some of my HDDs to see if it had an effect but it didn't. I'm managing to run the pc using the internal graphics chip, the gcard is still in the system with the green LED and the fan running but no output.
I'm running a BFG 9800GTX+ which comes overclocked in the box; Asus M2N-VM HDMI nForce630a Socket AM2+ Motherboard; Athlon 64 X2 5200+; 4GB RAM; ENERMAX Liberty 400W
Basically I'm looking for the the root cause of the failure, whether it's the gcard, insufficient power supply or something else like the mobo. Any help would be appreciated.