First test for see if your input cards are working
How can i tell if there is a problem with my input card or my video source ?
Most of the live input capture cards will send a default signal that you will be able to see in the interface if you select the live input, listed below are the different signals that are sent when a card is working correctly but does not have a signal
VGA Input Card = "no signal" , "no input"
Composite or s-video = Blue screen
SDI (sweetspot driver) = Black Screen
Blackmagic cards = Black magic logo
You can test your inputs with AmCap a low cost app (
http://noeld.com/programs.asp?cat=video)