Here is a simple step-by-step guide which can help you to downgrade iOS 4.3.1 back to iOS 4.3/4.2.1/4.1/4.0 or iPhone OS 3.1.3/3.1.2 on your iPhone 4/3GS, iPod Touch 4G/3G and iPad 2/1st-Gen. In order to downgrade firmware of your iDevice, all you need is SHSH blobs for the firmware to which you want to downgrade. Also note that, downgrading your iPhone firmware do not mean that you are also downgrading your baseband.
- Download iTunes 10.2.1 from here
- Download iH8sn0w's iREB RC4 from here. This will help you to avoid 1600, 1601, 1602, 1603, 1604 and 1015 iTunes errors. If you are on Mac, use this instead of iREB.
- Download stock IPSW of the firmware to which you want to downgrade. All those iPhone users with iPad baseband 06.15.00 can not restore stock IPSW on their iPhones due to baseband protection by Apple, so you have to create the custom IPSW of a firmware to which you want to downgrade using PwnageTool or Sn0wbreeze tool.
- Download TinyUmbrella for Windows or Mac from here
Download iOS 4.3 for iPhone 4/3GS, iPod Touch 4G/3G, iPad 2/1st-Gen & Apple TV 2G
Download iOS 4.2.1 for iPhone 4/3GS/3G, iPod Touch 4G/3G/2G & iPad
Download iOS 4.1 for iPhone 4/3GS/3G & iPod Touch 4G/3G/2G
Download iOS 4.0 for iPhone 4/3GS/3G & iPod Touch 2G/3G
Download iPhone OS 3.1.3 for iPhone 3GS/3G/2G
Download iPhone OS 3.1.2 for iPhone 3GS/3G/2G
Step to Downgrade iOS 4.3.1 to iOS 4.3/4.2.1/4.1/4.0/3.1.3/3.1.2:
- Connect your iPhone, iPod Touch or iPad to your PC or Mac via USB cable.
- Launch TinyUmbrella and wait while it detects your iDevice.
- Once your iDevice has been detected by TinyUmbrella, select it from the side-panel and hit the Save SHSH button. Now wait while TinyUmbrella saves your SHSH from Cydia server to your hard-disk drive locally. After saving all of your SHSH blobs to your PC or Mac, leave TinyUmbrella window open in background.
- Launch iREB tool and select your iDevice from the displayed options. Make sure that iTunes is not running in background.
- Now use the following instructions to put your iPhone in DFU mode:
- Turn off your iPhone completely
- Press and hold the Home+Power button simultaneously for 10 seconds.
- After 10 seconds, release the Power button but keep holding the Home button until iREB detects your iDevice in DFU mode.
TSS Server Started!
TSS Accepting connections...
Stuck in Recovery Mode After Downgrade?
If your iPhone, iPod Touch or iPad gets stuck in recovery mode after firmware restore, you can try the following tools to kick your iDevice out of recovery mode loop:
- If you are downgrading to iOS 4.3, use TinyUmbrella (Fix Recovery) for iOS 4.3
- If you are downgrading to iOS 4.2.1, use TinyUmbrella (Fix Recovery) for iOS 4.2.1
- If you are downgrading to iOS 4.1/4.0, use TinyUmbrella (Exit Recovery)
- If you are downgrading to iPhone OS 3.1.2/3.1.3, use RecBoot or EasyiRecovery
Jailbreak Your iDevice After Downgrade:
- Jailbreak iOS 4.3: Swn0wbreeze 2.3b4 [How-To], PwnageTool Bundles
- Jailbreak iOS 4.2.1: GreenPois0n RC 6.1 [Windows | Mac OS X]
- Jailbreak iOS 4.1/4.0: Limera1n [Windows | Mac OS X] [JailbreakMe for iOS 4.0.1/4.0]
- Jailbreak iPhone OS 3.1.3/3.1.2: Spirit [How-To]
Tips for Downgrading Your iDevice Firmware:
- After step 8, open http://gs.apple.com/ in your default browser, it should redirect you to Cydia homepage.
- To use TinyUmbrella, you must install most updated version of JDK which you can get from here
- If for some reason TinyUmbrella is not working, just add the following line to your Windows or Mac HOSTS file. In this way, you can skip step 2, 3 & 8.
- If you do not see any SHSHs in TinyUmbrella after step 3, you are not eligible for downgrade. At this moment, downgrading your firmware without SHSH blobs is not possible.
- Click on the respective links to solve the following errors which you can encounter during the downgrade process:
You may also like to read:
- Download RecBoot to Fix iTunes 1015 Restore Error
- Download RecBoot v1.3 for Windows, Mac OS X & Linux
- Fix iTunes Error 3194 While Restoring iOS 5.1.1 on iPhone, iPod & iPad