I've used 6 1920x1080 monitors connected to a Gigabyte Vega 64 card for months. Yesterday, Vega 64 card stopped outputting video to three of them (all three DP ports). Software still sees all six, but now no video/settings on three of them (HDMI monitors still work fine). I have tried a new power supply (850w), made sure both 8-pin power connectors are using discrete power cables, flashed card to F2, re-installed drivers, tried swapping video cables, nothing works. Plugging one of the working monitors into one of three dead ports (even with new video cable) does not work, it is definitely all three DisplayPort ports stopped outputting video. Turning on any monitor plugged into those three ports causes ALL monitors to flash continuously. Ideas? Warranty issue?