Can't get past "press a to start"

now after 6 hours of texting with xbox service they told me to ask in this forum…
i have this problem where i can’t get past the “press a to start” nothing happens when i press a
i have tryed a lot of different things like uninstalling and reinstallig, setting my xbox to factory new ect.
i hope there is someone that can help me because i have been really exicted to play forza 4… (:

Did you solve this problem? I have the same issue. Also there is no sound in the game now.