iPhone OS 4.0 is now being adopted by many iPhone users as it features a loads of new specifications such as multitasking, iAD, etc. You can read iPhone 4.0 OS features here. However, if you don’t find the iPhone OS 4.0 interface more comfortable, you can downgrade iPhone 3G to 4.0 firmware back to 3.1.3 firmware. Downgrading to the latest stable OS will give you a bug free experience.
Do note that using the below tutorial you can only downgrade your firmware but your baseband will not get changed, which means that you can’t unlock your iPhone 3G even after downgrading iPhone OS 4.0 to iPhone OS 3.1.3 firmware successfully.
How to Downgrade iPhone 3G 4.0 OS to 3.1.3 Firmware
- Download iPhone 3G 3.1.3 firmware
- Connect your iPhone 3G to a computer
- Run iTunes 9.1 >> Press Windows (Press Alt Key+ Click Restore), on Mac (Hold Option + Click Restore) >> Manually select iPhone 3G 3.1.3 firmware
- You may see a 1015 error >> Click on Ok and close iTunes
- Open terminal on Mac/Command Prompt on Windows and type following commands
- Unplug your iPhone >> turn it off by pressing the home+power button
- Again turn it on by pressing the power button >> Plug-in your iPhone >> Load iTunes to continue with the activation
- You are done.
. / iRecovery -s
setenv auto-boot true
iRecovery Last Command fsboot
Now you have successfully downgraded iPhone 3G 4.0 to 3.1.3 firmware. [via]