Hey

have same problem on 12%

There is a cure YOU MUST :P replace battery with charged battery, Problem is your battery is runned dry, and when you connect USB your phone starts update but hang on 3% AND DONT CHARGE!! This is important!! And when you put charged battery HOLD U and connect USB the MAGIC Usb ICON APEARS and you can flash anything So don't worry I've got same problem and i have Ressurected my phone!