I will not be responsible if you ruin/damage your phone while using this. It's an extensive menu, lots of tests, an option for the factory reset (the power+vol+home option) and more info than you can shake a stick at. I know it can be destructive - it already wiped my APN settings, so watch out. Use at your own risk ! Dial 3845#*509# NOTE : after playing with it some more, it appears to be available on 2.2 through 2.2.2. Your mileage may vary depending on what you use on your phone. Good luck !