Same happend to me the phone its tethered i think, i solved this way:
First i uploaded original firmware 4.2.1 from apple, this caused me error 1015,closed itunes, after that i opened tinyumbrella and started tstt server, with redsn0w i entered into pwned dfu mode and again open itunes and use the custom firmware that you will make with the sn0wbreeze using only "hactivation" and thats all, after custom firmware update will be working, just in cydia download ultrasn0w for unlock.
Good luck. |