I bought a card (MSI 780 ti) from a friend, and it may have been damaged in shipping. When I install the nvidia drivers, initially the card seems to work at 2D clocks, but as soon as anything kicks the card into 3D clock speeds, it blacks out, and my PC reboots. I've checked my PSU, it doesn't seem to have any issues with two 280x's in crossfire, so I don't think that's the problem. Any ideas? Is my card dead?