How to Downgrade iOS 4.3 to a 4.2.1

Share

 This guide will help downgrade iOS 4.3 to iOS 4.2.1  and  fix the iTunes 10.2.1 error 1013.
Currently it is possible to downgrade its iOS 4.3 to a previous iOS if you do not meet certain requirements:



you must have your SHSH  saved before proceeding  to the iOS downgrade.
Again, as a reminder the baseband version changes with each iOS update  and there is no turning back to an older version baseband. The Current Baseband version only allow to restore an iOS version that corresponds to baseband (for the latest version of baseband).
Although you changed the host file or use TinyUmbrella TSS with its server,you get an error of type 1013 following the restoration of the iOS 4.2.1 with to the iOS SHSH

1. Run the software iTunes , restore iOS 4.2.1 with the ALT key (Ctrl for Windows) + click on "Restore" in iTunes.
2. Restoring runs but will crash at 3 / 4.
3. Wait for the error 1013 via iTunes.
4. Close iTunes .
5. You are in to Recovery.
6. Press the button (above) and Home (down) until the expiry of your iDevice.
7. Then immediately go into  DFU mode, press the ON button 3 seconds and then ON + HOME for 10 seconds, then HOME button just 17 ​​seconds.
8. Launch the Greenpoison jailbreak software.
9. Follow the steps in the guide after switching to jailbreak DFU mode.
10. Your iDevice then jailbroken 4.2.1 under iOS then connect to iTunes to finish its activation following the restoration of previously iOS 4.2.1.

Note: You must have the original SIM card to activate your iPhone after restoring the IOS.

Posted in: Apple,Baseband,downgrade,downgrade iOS 4.3,error 1013,greenpoison,iDevice,iOS,iOS 4.2.1,IOS jailbreaking,IPhone,ITunes,Microsoft Windows,Subscriber Identity Module