2007 Volvo C70 SE D5 Sat nav?

Unit stop working but flip up screen keeps opening on its own and reads insert disc, which i have never had to do in the 10years i have owned the car. When turn off the car there is a humming sound from behind the dash, (and no its not a Bird) i have to turn the ignition switch off twice so the screen goes back down and the Car battery does not go flat.

i have removed the unit and is it possible to replace some of the 5 Connections so that i can still access some of the unit functions and leave the Sat Nav isolated and screen down , which connections it or combinations there of, Grey , Black, Green, Blue or Yellow is connected to the sat Nav for these functions.and which is the power connection. Thanks All