I ran into this as well when adding my laptop as a diskless MD, turns out it chose to use the VGA-out instead of the built in screen and connected TV. Pressing "1" fixed it, "2" puts it back on the VGA monitor and "3" tries to use the TV-out, I think, which keeps crashing to textmode on my lappy.
So, as said earlier, if you get no signal or screen, hook up as many outputs as you can and try pressing "1", wait a while, then "2" and so on, untill you see the AVWizard (or it keeps going back and forth to text mode, in which case I suggest to reboot and try again).