ASUS P8Z67V-pro no video out when gfx card installed

Hey I have just assembled a new system build

i7 2600k @ stock clock with stock cooler
ASUS P8Z68-V pro mobo
8 gigs of DDR3-1600 RAM @ 1.6V
Rosewill 1000 watt PSU
EVGA GTX 560

Without the graphics card installed everything works like a charm. I just plug my monitor into the mobo's DVI plug and everything is fine, however, when I install a discrete graphics card the computer powers on, the fans run, lights blink, but no video output from any of the DVI or VGA plugs on either the discreet card or the mobo itself. I have tried 2 EVGA GTX 560 (for an SLI setup) and an old PNY GTX 250 X8 edition graphics card and they all have the same issue. Any suggestions?

Set the graphics init to PCIE/iGPU also turn off the igpu in the bios then connect to the GPU for output should be fine. If you want to use virtu set it up first then run the igpu out which will piggyback your Nvidia card's signal.