How to Downgrade iPhone 3G 3GS OS 4.0 Beta Back to 3.1.3

by admin on April 16, 2010

Following is the guide to downgrade your iPhone 3G and 3GS from firmware 4.0 beta 1 to firmware 3.1.3, This guide is tested on both Mac and Windows machines.

Step 1. Download iTunes 9.1 and Firmware 3.1.3, install iTunes 9.1 and place firmware 3.1.3 on desktop.

Step 2: Connect your iPhone via USB and put it in DFU mode (hold down the button “Power” and “Home” for 10 seconds then release just the power button).

Step 3: When your phone is in DFU mode manually install firmware 3.1.3 (by pressing Shift + Restore and select the firmware you downloaded previously).

Step 4: If you encountered an error message like 1011, 1013, 1015, just ignore them(Actually the firmware3..1.3 is already successfully installed) and use iRecovery to get the hold of your iPhone again.

Download this package [Download Here] included iRecovery for Windows & Mac and LibUsb-Win32. Windows user also download Latest version of  iRecovery [Click Here]

1) Windows users Install libusb from the downloaded pack, Mac users can skip this step. If you are on Windows Vista / Windows 7 then follow the steps given below to install Libusb-Win32.

  • Right click on this file. Select Properties | Compatibility Click the “Run this program in compatibility mode” box and select  “Windows XP (Service Pack2)” from the drop down list.
  • Right click again and select “Run as “Administrator”. Follow the installation instructions. Running the test program list the usb devices plugged into my computer – but not my new device.

2) Start iRecovery in Terminal / Console with iRecovery -s

3) Execute the following commands:

  • setenv auto-boot true
  • saveenv
  • reboot

Step 5: Reboot your iPhone (keep holding home + sleep for 10 seconds).

{ 3 comments }

Bjarni F. April 29, 2010 at 3:20 am

Thanks for the instructions:) Worked like a charm.
I had os 4.0 beta 2, and this works for that also.

Sahil July 10, 2010 at 11:26 am

LibUsb-Win32 contains Virus it will block all ur usb ports and very harmfull for ur compputer……… Do noT Download It…..

Gaius Caesar July 15, 2010 at 2:52 am

Does this method bypass the need for the SHSH blobs with Cydia? I see no mention of it. If that’s the case will it work with 4.0 official, or only the beta?

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