farmtruc

I have a spare vizio hdtv that i wanna use for display. currently my gv card is in the pc, obviously, but i would like to use the tv out port and display the camera's on the vizio tv. i hook a video rca cable to the tv out and to the input av1 on the tv, the screen is blank, but does change from the default blue screen "no signal" so something is coming across the wire. any suggestions on to get the secondary view to display on my tv? thanks, allen