My friend gave me a used G1, and I wanted to set the passwords to factory settings so I could set up email, download apps etc. So I powered off phone and held down the "home" and "end" button. The phone took me to a the Android system recovery screen. I selected Alt+W to wipe data/factory reset. No screen came up with triangle with exclamation. Now I have a blank screen and the phone won't do anything. What should I do.. please help!