I updated my US Cellular Galaxy S3 to kitkat and 3 days later it shuts off randomly and wont turn back on. i brought it to us cellular and they tried wiping it through the recovery but no dice. i have tried flashing it like a million times but nothing works, it just boot loops and now it wont go into recovery mode, just downloading mode. i dont know what i should do. i downloaded the android toolkit but i cant flash anything because the phone isnt in USB debuging mode and since it wont turn on i cant put it into it. any help would be great!