Downgrade iOS 4.3.3 to 4.3.2, 4.3.1, 4.3, 4.2.1 on iPhone 4, 3GS, iPad 2, iPad, iPod touch
iOS 4.3.3 has been released by Apple for iPhone 4, 3GS, iPad, iPod touch 4G/3G to fix the location tracking bug found in iOS 4.x devices. If you have upgraded to iOS 4.3.3, and now want to downgrade back to iOS 4.3.2, iOS 4.3.1, iOS 4.3, or iOS 4.2.1, simply follow the instructions below to downgrade iOS 4.3.3 on iPhone 4, 3GS, iPod touch, iPad 2 and iPad 1 to iOS 4.3.2, iOS 4.3.1, iOS 4.3, iOS 4.2.1. This guide will only work if you have SHSH blobs saved for the respective firmware you downgrading to. Proceed to downgrade guide.
Step 1: Download the old ipsw firmware files from links below.
Step 2: Put your device into DFU mode (not recovery mode).
Connect iOS device to computer.
Turn it off.
Hold Power and Home buttons together for approximately 10 seconds.
Release Power button but hold the Home button yet until your computer recognizes a new USB device.
iTunes will recognize iOS device (iPhone, iPad or iPod touch).
Note: iPhone, iPad or iPod touch screen at this time should be blank (black), if not, then you are most likely in Recovery Mode, not DFU mode.
Step 3: Now you have to trick iTunes to make it believe that it is watching Apple servers, while in real, we are going to change the address to Saurik’s server. To do this:
If Windows, navigate to C:\Windows\System32\drivers\etc\ and locate “hosts” file.
Mac OS X users can get to “/etc/” directory by going through “Go –> Go to Folder” from Finder.
Open this “hosts” file in Notepad (for Windows) or TextEdit (for Mac OS X) and add this line at the end of file contents:
Save this file, close it and proceed further.
If using Windows 7 and Vista, start “Notepad” with Administrator privileges by right clicking on “Notepad” , and click on “Run as Administrator“ option otherwise it might not save the changes you made in the file.
For Mac OS X users, make sure you have full read and write permissions on your account when you are saving the host file. If it shows permissions error, Copy the host file to desktop, make the required changes, and replace it with the original file in “/etc/” directory.
Step 4: Start iTunes
Click on iOS device icon from the sidebar in iTunes.
Press and hold left “alt” (option) button on Mac, or Left “Shift” button for Windows on the keyboard and click on “Restore” (Not “Update” or “Check for Update”) button in the iTunes and release the button.
iTunes will prompt you to select the location for your iOS 4.3.2, iOS 4.3.1, iOS 4.3, iOS 4.2.1 or below firmware file. Select the desired ipsw file and click on “Open” to restore your iOS device.
iTunes will do the rest for you involving a series of automated steps.
Be patient at this stage and don’t do anything with device.
Just wait while iTunes installs the requested firmware on your iOS device.
Your device screen at this point will show a progress bar indicating installation progress.
After installation, it will reboot automatically.
In few cases while restoring to iOS 4.3.2, iOS 4.3.1, iOS 4.3, iOS 4.2.1 or below, iTunes might show 1013 error. This is normal so just ignore this error as the firmware has already been successfully installed on the device.
Incase of the unknown error, your iPhone, iPad or iPod touch will be stuck in Recovery Mode, showing that “Connect to iTunes” screen.
Exit Device from Recovery Mode
To exit your device from Recovery Mode, download TinyUmbrella.
Download Tiny Umbrella
Download Fix Recovery Mode
Run it and the click on “Exit Recovery” button. Your device will now restart normally.
You should now be able to jailbreak and unlock your device on the older iOS 4.3.2, iOS 4.3.1, iOS 4.2.1 or iOS 4.1 firmware.
Remove 126.96.36.199 gs.apple.com line from the host file so that you are prompted for future updates from Apple via iTunes.