Oldstone Place

If you upgraded your iPhone to version 3.1 and for some reason you want to rollback to OS version 3.0 or 3.0.1, here’s how.

1. Download the 3.0.1 firmware from here.
2. Connect your iPhone 3G or original iPhone to iTunes .
3. Switch off your iPhone by holding the power button for a few seconds, then slide when it tells you to.
4. Put your iPhone into DFU mode by pressing both the Home and Power On buttons for about 10 seconds.
5. When you see the Apple logo, release only the power button, and keep pressing Home until the USB – iTunes screen appears.
6. iTunes will say it’s detected an iPhone in Recovery Mode and tell you that you need to restore it. Click Ok.
7. Now press and hold down the Option key (for Mac) or Shift key (for Windows) and click on the Restore button in iTunes.
8. In the window that opens, select the firmware you downloaded. Usually this will be iPhone1,2_3.0.1_7A400_Restore.ipsw
9. You’ll get an error message at the end of the restore, probably 1015. Don’t worry, the next step will fix this.

How to fix the Recovery Loop:

I tried the Hackintosh iRecovery Package but it didn’t work for me. I had better success with QuickPwn.

1. Leave your phone in DFU mode and close iTunes.
2. Download and unzip QuickPwn22.zip
3. Run QuickPwn22-1.exe and wait for the message to appear. Don’t close the message yet.
4. Hold Power and Home for 15 seconds, then release Home and wait 2 seconds, then release Power.
5. The Apple logo will be displayed, then you should see a progress bar while QuickPwn does its work.
6. You can now exit QuickPwn and open iTunes.
7. iTunes will tell you set up your phone. You will have to set up your iPhone up as a new phone, or you can try to restore from backup if you have any backups at version 3.0.1 or earlier. You cannot restore backups of OS 3.1. I set mine up as a new phone even though I knew I’d have to re-enter settings for things like mail, Wifi, and various applications. Restores take a looong time…

Now that your phone is running 3.0.1 you can try tethering (Mac) or tethering with Windows, or see here for tethering with Softbank.

Enable Tethering with Softbank

1. If you are using iTunes 8.2 or later, then close iTunes and run the following command.
   For Mac users, open Terminal, and execute:
   

   defaults write com.apple.iTunes carrier-testing -bool TRUE

   Or on Windows XP, open a Command prompt (Win+R, cmd) and run:

   "C:\Program Files\iTunes\iTunes.exe" /setPrefInt carrier-testing 1

2. Plug your iPhone into your computer via the USB cable
3. In iTunes, display the summary page of your iPhone
4. While pressing the Option key (Mac) or Shift key (Windows), click on the "Update" button.
5. Select the Softbank_jp.ipcc file.
6. iTunes will now update your iPhone with the modified carrier settings
7. Once finished, unplug the iPhone, go to Settings>General>Network, and enable tethering.