I bought my car a few weeks ago. I dont think the car had nav to begin with but the guy before me put in the stock infiniti navigation system and screen. The screen itself doesnt turn on, and it wont go down either. The dvd player isnt hooked up. Is that why their is no power to the screen? I took the center console apart and took this picture of the back of the navigation screen. It looks like their are a few harness' missing?

thanks!