Try reseatting your video card in your first pciex slot closest to your cpu then make sure its in properly and held in place. Then disconnect and reconnect the power cables to it and try again. Use dvi or hdmi if you can to connect the card to your monitor. You may needif to clear your mb bios using pin, jumper or button on your mb. if it doesnt work try plugging your video cable in the onboard port if your cpu has an integrated graphics unit.there should be an option in your bios to set which adapter to default to.