gigabyte ga-z77-d3h motherboard
corsair 750t power
MSI gt680 vid card
When I first turn comp on I can see the motherboard setup screen for 5 sec. then moniter goes blank,when windows starts I see it also for 5 sec. then blank again.If I turn moniter off the on I can see whats on the screen for 5 secs.Have reseated card a few times and got it working for a couple hours then net time i turned it on back to the same.Tech support says its a bad card but im sceptical .Anyone else got an idea?
The fact that the display does turn on, and off again, indicates to me (just a guess), that maybe a pin in your cable or output on your GPU is damaged slightly. Pretty much was it_dan_zsu said.
To actually certify that its your GPU causing the issue, take it out, and use your CPU to get display. If there are no issues there, you can single out the GPU as an issue. If the GPU is an issue, and worked fine on the CPU, then the cable can also be ruled out.