Three possibilities.
1) Flyer card is broken, send it to Newtek and they will fix it.
2) Cable is broken, see #1
3) Cable is not being plugged in correctly, fix that and try again.
Plus we really need more info.
1) Output and Preview both effected?
2) Software loaded for Flyer?
3) Does the Flyer capture video?
4) Is your source TBCed?
5) Is your source terminated?
-Tig