Although the ios5 jailbreak has appeared perfectly, here we also provide a tutorial for users who accidentally upgrade IOS 5.0/5.0.1 to ios4.3.3, or who cannot tolerate ios5 power consumption after the upgrade.
The premise of downgrading to the old IOS version is that you have to save the shshblobs of the old IOS version (tinyumbrella backup is usually used and click to view the detailed tutorial). Here we need to prepare the shshblobs of ios4.3.3.
You also need to download the following files:
Redsn0w0.9.9b8 (click to download win
Click to download the Mac version)
Tinyumbrella (click to download)
ITunes (click to download)
Ios4.3.3 firmware (click to download the iPhone 4 ios4.3.3 firmware
Click to download firmware from another device)
Step 1:Switch the device to DFU mode (connect to the computer, press and hold the power key and Home key after the device is shut down for 10 seconds; then open the power key, but do not open the Home Key until the computer prompts to find the USB device .)
Step 2:Open redsn0w> extras and click pwneddfu. The screen of the I device is still black.
Step 3: Open tinyumbrella, select the device and backup 4.3.3shsh file, and click starttssserver.
Step 4:Enable iTunes, press the Shift key on the keyboard, and then click Restore (the MACOs press the option and the iTunes restore key), and select ios4.3.3 firmware.
Step 5:If a recovery error is returned (1), disable iTunes and exit.
Step 6:Click Advanced in tinyumbrella to remove "sethoststocydiaonexit ..." And disable tinyumbrella.
Step 7:Enable redsn0w> extras> recoveryfix. At this time, the I device screen displays a process similar to the jailbreak process, and then returns to the black screen.
Step 8:Enable redsn0w> extras> justboot. The device starts and you will see the pwnapple logo. Then, your I device is successfully restored to 4.3.3.
Step 9:Then enable the iTunes activation device.
Note: This article Reprinted from: http://bbs.weiphone.com/read-htm-tid-3637685.html