DVI-D output will not display on AMD R7 240. The monitor gets some signal because it notified me when I unplug the cable, but there's only a black screen. The computer will recognize a 2nd monitor because it will switch to the DVI display by default when both VGA and DVI are plugged in. There is still only a black screen for DVI though. Tried single monitor, dual monitor, reinstalling drivers, rebooting. Any suggestions?