2010

HOW TO: Downgrade iPhone OS 4.0 To 3.1.3 [ Mac and Windows ]

Well i had a good run with iPhone OS 4.0 beta 1 but today i decided to downgrade. The beta is really really buggy, and i got tired of my phone rebooting every time i was trying to call somebody, and i really need the ringer toggle since my silencer switch is broken. So, if you want to downgrade, follow the guides below..

Mac

You will need:

How to do it:

1. Donwload the stock 3.1.3 fw, iRecovery and Libusb on your mac. Install the LibUSB package

2. Connect your iPhone via USB, load iTunes and alt+restore with the original 3.1.3 firmware

3. During the restore process you will get an 1015 error. Don’t worry, that’s normal. Just click on and close iTunes.

4. Open a terminal shell and drag and drop the iRecovery icon on it. You will get the path to iRecovery that should be followed by a “-s” ( without the quotes and you should type -s. Press enter )

5. Now iRecovery should recognize your iPhone and you will get something like this…

6. Now you need to type:

  • setenv auto-boot true ( hit enter )
  • saveenv ( hit enter )
  • fsboot ( hit enter )
  • exit ( hit enter )

7. Unplug your iPhone and turn it off by pressing the home+power button. Once it is off, turn it on by pressing the power button. Plug-in your iPhone and load iTunes to continue with the activation.

8. That’s it. Enjoy

Windows

Later update:

One of our readers, just sent us some valuable tips for all you Windows users:

If you’re running Windows 7 (at least 64 bit) it is critical that you use the newest version of LibUSB though (1.2).  installing 1.12 under windows xp compatibility does not seem to work.  Also, one needs to download both of these libUSB zip files (or perhaps just the devel file (not sure).  the first one alone does not work though.

libusb-win32-bin-1.2.0.0.zip
libusb-win32-devel-filter-1.2.0.0.zip (this is the actual installer)

[thx Santi Roberts]

The exact same process but you will use Windows console, and you will need this files:

NOTE: for iPhone 3Gs, you can downgrade to 3.1.3 ONLY, unless you saved your ECID files to a earlier version.