Downgrade iPhone 3G OS 4.0 to 3.1.3 or lower

Downgrade iPhone 3G OS 4.0 to 3.1.3 or lower

Step by Step Guide to Downgrade iPhone 3G

Step 1: Make sure you have latest iTunes installed, Now connect your iPhone to your computer.

Step 2: Put your iPhone 3G in DFU mode with following instructions.

Connect your iPhone to your computer.
Turn iPhone off.
Hold power and home together for 10 seconds (exactly).
Release power but keep holding home until the computers beeps (observed on a PC) as a USB device is recognized.
A few seconds later iTunes should detect your iPhone.
If the Restore Logo is present on the screen, you are in Recovery Mode, not DFU.

Step 3: Once your iPhone is in DFU mode following message will be appeared in iTunes. Click on “OK” , Now hold Option key while clicking Restore in iTunes and browse the OS 3.1.2 or below firmware for your iPhone 2G, 3G. Now the restore process will take 10 – 15 minutes.



Step 4: If you encountered an error message like 1011, 1013, 1015, just ignore them(Actually the firmware3.0 is already successfully installed). Simply launch RedSn0w and do the Jailbreaking Unlocking process again.

But if you encountered with error message like 1601, 1602, 1600 or anything else then try putting the iPhone into DFU mode and try again.

Disclaimer : This process is universal and tested several times though we are not responsible for and damage (if any) so use it at your own risk. If you like our work then consider to digg the story and help us by spreading the word.

Courtesy: @ihackinjosh