bling_vp

I have a pioneer avic n3 everything is plug up , but there power but nothing else happen. Was installed by a professional but he don't know what it might be. Can anyone help or is there somewhere I can get it fix at. And is it worth fixing since I bought it second hand. And again you can see the fan run and the nav cd comes out but no light or anything esle happen. Then it stop. No power. Much appreciated advice needed Thank.