I have something of a puzzle here with a Samsung 48" 6700. If I have the output set to 60 Hz when powered on, it comes up with a black screen. If I have it set to 30 Hz at power on and then switch the output to 60 Hz, it works fine. I have UDH mode on. I am using a DVI to HDMI cable, I don't know if that could be contributing to the problem, but I would think it would either work or not work? I've had this for less than a week, might I have a defective unit? Newest nvidia drivers, win7 with most all updates (minus the win10 nags).