Working on an iPhone 4. Unknown iOS version, age or history of phone. Plug it into the wall and the "USB Connect to iTunes" logo comes up. Connect to the computer and iTunes won't recognize the iPhone as is. Entered PWNED DFU mode via iReb and attempted a straight restore via iTunes... after about 15 seconds the iPhone screen starts cycling from black to the Apple logo, back and forth every 8 seconds. Tried same as before, only this time have the 5.1 IPSW downloaded.... did the Shift-Restore and selected the 5.1 IPSW and still begins to cycle back and forth the black screen and Apple logo. With both methods, the iTunes status bar continues to say "Verifying iPhone restore with Apple" until a 1602 error comes up eventually. Suggestions?