The millions of Xbox Live players who were banned because of their modded Xbox 360 consoles may get a second chance with some firmware workarounds. Beware though, it’s a complicated process.
First you’ll need to get iXtreme LT, which’ll attempt to return your console to a playable state. The catch is that you need to know your CPU code and that the instructions rely on a lot of different (free) tools.
Let me know if that worked for you.