The following step by step guide will help you downgrade your iPhone with firmware 4.0 to firmware 3.1.3. or lower . For those of you who upgraded to the latest firmware update iOS4 on their iphone devices here are the instructions on how to downgrade iPhone firmware 3.1.3 or 3.1.2.
Steps to downgrade Iphone 3GS – Ipod touch firmware :
- Download iPhone 3G 3.1.3 firmware
- Connect your iPhone 3G to your PC
- Run iTunes 9.1 & Press Windows Key on PC (Press Alt Key+ Click Restore), on Mac (Hold Option + Click Restore) . Manually select iPhone 3G 3.1.3 firmwar
- You may see a 1015 error . Now Click on Ok and close iTunes
- Open the Terminal on your Mac or Command Prompt on Windows system and type the following commands
. / iRecovery -s
setenv auto-boot true
iRecovery Last Command fsboot
irecovery last command fsboot
Unplug your iPhone and restart it. Now load iTunes again to continue with the firmware activation.