I'm wanting to use the External 2 option with Vmix. Right now I'm coming out of a Blackmagic Intensity Pro card (HDMI Out) and going into a HDMI Splitter and sending the output signal to those TV's just fine.

I have 2 monitors hooked up and want to come out of the HDMI out on the same graphics card to another HDMI Splitter so I can send the EasyWorship feed that is coming in on DeskTop Capture Input to those TV's. My problem is every time I hook up the HDMI cable to the HDMI Output on the Graphics card my main monitor goes Black. Unplug the HDMI cable and the picture comes back on the main monitor. I also tried to unhook the 2nd monitor and just use one monitor and the HDMI out to see what happens. Same thing, my main monitor goes black. I have a mouse but NO desktop. I'm using Windows 7 and vMix HD 12.0.0.129. Any help would be greatly appreciated. Thanks.

Do you have your graphic card settings set to Extend?

Press the Win + P key to being up the menu, choose Extend.
Your display should refresh and then send out to your second monitor.

Windows being the wonky beast that it is, sometimes it takes a few tries to get it to work, but once it does, it "should" remember the settings.

;)