Finally got a new Xbox 360 E that works, but when I try and enter a public match, I can never find one.
But here is the kicker, I only ever find a match when my connection type is on 'Any' and I can only get in a match when one other person in the world is in that game.
I have been in about 50 games since I got my Xbox, I have always exited the lobby and re-entered and I am always in the game with the exact same person.
He goes offline and I no longer find any matches in any game mode at all.
You NAT is set to either "Strict" or "Moderate." You need to get inside your router settings to change this to "Open." I just went through this with my little brother 1500 miles away. AT&T told him there is no such thing as "NAT" and that "It must be something only Microsoft can adjust." It took me 15 minutes to get him to download a program so I could remote access his PC and then his router. It took me less than 5 minutes to find where to adjust the setting and do so. AT&T couldn't do it after an hour and a half.
Since then ... lil bro has no problems finding matches or hooking up with friends.