How To Downgrade iPhone 4.0 Firmware to iPhone 3.1.3 Firmware

If you are currently on iPhone firmware 4.0 and want to downgrade back to iPhone firmware 3.1.3 to get different apps, to jailbreak, or what ever the reason may be, follow this guide for PC and Mac.

FOR MAC

Notes – Read Me Before Continuing

Before we begin, please take some time to review the notes below as they are very important:

– The method listed below can be followed on a MAC only

– The method listed below can be used for an iPhone 2G, 3G, 3GS

- Your iPhone must be updated to firmware 4.0 via iTunes before beginning this process, which may require a developer account

– Your iPhone must have its ECID on file with Cydia from a previous jailbreak

– Ensure your iTunes is the latest version

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How To Downgrade iPhone 4.0 Firmware to iPhone 3.1.3 Firmware – MAC

1.) Download the following items to your Desktop:

2.) Connect your iPhone to your Mac via the iPhone USB cable and open iTunes.

3.) Put your iPhone into DFU mode by doing:

  • Press and hold the Home Button and Sleep/Wake button for exactly 10 seconds.
  • At the 10-second mark, release the Sleep/Wake button but continue to hold the Home button.
  • At this point, iTunes will pop-up with a message indicating it has detected an iPhone in Recovery Mode.
  • If the screen on the iPhone is ALL BLACK, then you are in DFU mode. If there is an Apple logo, an iTunes logo or anything else other than BLACKNESS on the screen, you are not in DFU mode. Redo the process.

4.) When the iPhone appears in iTunes on the left side and is correctly in DFU mode, select the iPhone and hold “Option” on the keyboard and click “Restore” in iTunes.

5.) A Finder window will pop-up where you will select the iPhone 3.1.3 firmware you downloaded in Step 1.

6.) During the restore process, iTunes will produce “Error 1015”. This is normal. Ignore the error and click “OK” and then exit iTunes.

7.) On your Mac, open the Terminal application and type the following:

  • /users/username/Desktop/iRecovery -s

Note that “username” is the username of your home directory on your Mac.

After the above is typed, press Enter. iRecovery will now begin its process by recognizing the iPhone and the Terminal window will be filled with many lines of text.

8.) When the Terminal application is no longer filling up with text, type the following next to “iPhone$” and hit Enter after each line:

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

9.) Unplug your iPhone from the Mac and reboot it by holding the Sleep/Wake button and Home button until you see the Apple logo.

10.) When the device is rebooted, plug it back into your Mac and into iTunes to complete the activation process.

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FOR WINDOWS

Notes – Read Me Before Continuing

Before we begin, please take some time to review the notes below as they are very important:

– The method listed below can be followed on a WINDOWS only

– The method listed below can be used for an iPhone 2G, 3G, 3GS

- Your iPhone must be updated to firmware 4.0 via iTunes before beginning this process, which may require a developer account

– Ensure your iTunes is the latest version

—————

How To Downgrade iPhone 4.0 Firmware to iPhone 3.1.3 Firmware – WINDOWS

1.) Download the following items to your Desktop:

2.) Connect your iPhone to your PC via the iPhone USB cable and open iTunes.

3.) Put your iPhone into DFU mode by doing:

  • Press and hold the Home Button and Sleep/Wake button for exactly 10 seconds.
  • At the 10-second mark, release the Sleep/Wake button but continue to hold the Home button.
  • At this point, iTunes will pop-up with a message indicating it has detected an iPhone in Recovery Mode.
  • If the screen on the iPhone is ALL BLACK, then you are in DFU mode. If there is an Apple logo, an iTunes logo or anything else other than BLACKNESS on the screen, you are not in DFU mode. Redo the process.

4.) When the iPhone appears in iTunes on the left side and is correctly in DFU mode, select the iPhone and hold “Shift” on the keyboard and click “Restore” in iTunes.

5.) A Windows Explorer window will pop-up where you will select the iPhone 3.1.3 firmware you downloaded in Step 1.

6.) During the restore process, iTunes will produce “Error 1015”. This is normal. Ignore the error and click “OK” and then exit iTunes.

7.) On your PC, click “Start” and “Run” and then type “CMD” without the quotations. Then type the following:

  • cd desktop (hit Enter)
  • iRecovery -s

After the above is typed, press Enter. iRecovery will now begin its process by recognizing the iPhone and the Explorer window will be filled with many lines of text.

8.) When the Explorer application is no longer filling up with text, type the following and hit Enter after each line:

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

9.) Unplug your iPhone from the PC and reboot it by holding the Sleep/Wake button and Home button until you see the Apple logo.

10.) When the device is rebooted, plug it back into your PC and into iTunes to complete the activation process.

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