Chroma key issues on Studio Pro HD Switcher

Hey all, forgive my ignorance, I've just started learning the Studio Pro HD switcher for my job. Unfortunately I can't seem to successfully chroma key a shot. It's simple, a couch in front of a green screen, but when I key out the green I just get black behind the couch. I can't seem to get anything to show up, media players or other cameras or anything. Am I missing something? Is there a "Set background" option for a chroma key?

Thanks so much in advance
-Adrian

Hi.
A key are a layer above the program row so your background are whats on the program row. Then you need to set up a upstream key with the green key signal and turn that key on. After that you should be able to key out the green part of the image.