Novia's Gourmet & Glamour Journey: How to Downgrade iPhone 3GS from 3.1.3 to 3.1.2

Saturday, March 6, 2010

How to Downgrade iPhone 3GS from 3.1.3 to 3.1.2

Please note that the following guide is for jailbroken iPhone 3GS and the jailbreaking methods that I had used are in the following links:

http://eatcookshoot.blogspot.com/2010/01/how-to-jailbreak-iphone-3gs-version-312.html
http://eatcookshoot.blogspot.com/2010/01/how-to-install-cracked-apps-on-iphone.html

It really pissed me off today when my iPhone shuts off, reboots and hangs out of a sudden when I was using it. The phone was connected to my laptop as I was charging it and when I opened itunes, I realized the firmware of my iPhone was automatically updated to 3.1.3 without my consent!

I was not able to find any suitable jailbreaking methods for iPhone 3GS 3.1.3 and hence the preferred and more stable method is to downgrade the firmware back to 3.1.2.

In this latest firmware update, apple actually prevents users to perform any downgrading. Hence the usual method of shift select to restore iPhone with your selected firmware will NOT work and instead you will get an error message pop up box.

Step by step guide -

The first requirement is that Cydia has your SHSH details stored for 3.1.2. If you have opened Cydia and seen green text at the top "This device has SHSHs on file for iPhone OS: 3.1.2" then you can restore to 3.1.2.

My equipments:
- iPhone 3GS
- Windows XP

*Yes I know this might sound stupid if you are in a situation with a iPhone that refuse to be turned on. So just proceed if your iPhone is as hung up as mine*

You need to edit your host file to connect to Saurik's server instead of Apples to sign the 3.1.2 firmware when you restore.

Download iPhone 3GS 3.1.2 firmware

Windows Vista and Windows 7 users make sure the program Notepad has Administrator privileges (find Notepad, right click, select Run as Administrator).

On your Windows PC Browse C->WINDOWS->system32->drivers->etc

(if you installed Windows on a different drive letter browse to that on instead of "C")

Right click on hosts and select Open.

Choose Notepad and click OK.

Add "74.208.10.249 gs.apple.com" at the end of the file. Save it.

Before continuing enter restore mode. One way to do this is disconnect your phone from the computer and turn your phone off. Start iTunes. Hold the home button on your phone and plug it in. Continue holding the home button until iTunes indicates you are in restore mode.