Downgrade from os 3.1 to old firmware like os 3.0

[Merino]

hi
The new firmware is release and some people installed it also ,but what with the downgrade from 3.1 to an old firmware like os 3.1. is there any possibility that can i go back to old iphone firmware like os 3.0? is that possible please help.
thank you

[Hakon]

Those using a jailbroken iPhone have probably not done the update to firmware 3.1 on Wednesday and they were right it would appear that Apple has chosen to enhance the safety of its device. Switch 3.1 is perhaps not as urgent as it seems this new firmware has some problems. But if you want to try what are the restrictions relating to jailbreak

[Gonzo]

i have read that it is possible to downgrade an iPhone firmware 3.1 to a previous version using iTunes 9 at least some thing somewhat tedious manipulation using QuikPwn.

[Simond]

Officially 9 iTunes does not restore a previous firmware to 3.1 if it has already been installed. Unofficially the downgrade is still possible. You will need using QuickPwn 2.2.5.

Procedure to Restore os 3.0 after installing os 3.1

start restoring an old firmware via iTunes. After a while it will stop with displaying an error message. Your iPhone will then switches DFU.
At this stage, run QuickPwn and follow the instructions provided by the software as you have done before. This will do what iTunes refuses to do: Turn your iPhone while it lacks the 3.1. Beware the baseband will not be downgraded! One was that the manipulation is risky can not succeed and is recommended by the teams of hack. Note that youe can definitely use iTunes 9 with a jailbroken 3.0.1 iPhone. There is no problem if one is careful not to accept the update to 3.1!

[Regina]

Downgrade iPhone 3GS 3.1 to 3.0

How to Downgrade iPhone 3.1 to 3.0 Firmware

• Start your iTunes 9 & Connect your iPhone 3GS
• put your iPhone on DFU mode with following instructions
  
  • Click this button for 10 seconds Home + Power On
  • Release the power button and continue
• message will be displayed Click on OK
• Now Press ALT key and click on Restore in itune
• Select iPhone 3GS 3.0 firmware
• A Confirmation will prompt .Click on Restore
• A Restore Process will start. At the end you will get error “Unknown error occurred (1015)”
• click on OK button
• Download iRecovery
• Extract connect of iRecovery on Desktop
• Go to Command prompt on Windows and type following
  

  cd Desktop
  iRecovery -s

• Once Message entering in Recovery Mode and Starting command prompt on screen type following command
  

  Fsboot
  iRecovery Last Command fsboot

• Once the iPhone 3GS will restart and you see the “Emergency calls only” and You need to reactivate iPhone 3GS via iTunes
  
• you can configure your iPhone 3GS as new phone