How To Jailbreak Your 4.0.2 iPhone

So you want to jail break your iPhone / iPod?  But it came out of the box with IOS 4.0.2, or you accidentally upgreaded to 4.0.2 before you found out that it isn’t supported by Jailbreakme, and you didn’t save a BLOB file.  A friend asked me to write up what I did to downgrade the IOS, and get Jailbreakme to install.  I take no responsibility for you screwing up your iPhone/iPod!  This is a fairly simple procedure, it worked for me.  And in fact, fixed a number of issues that I had been having with my phone.  I am not recommending you do this, and you do it at your own risk, even though the risk is minimal.

1. Download firmware 4.0.1 for your iPhone.  I’ll set up an ftp site later where you can get it if you can’t find it.

2. The file extension when downloaded is .ipsw – rename it to .zip and extract it whatever folder you want. whatever folder you want.

3. In the folder where you extracted the package, there is a file called “buildmanifest.plist”.   Open this file with a text editor (a TEXT editor, that means notepad for windows or TextEdit for Mac.  Now you’re going to change a few of the security entries.  This is simple, but be careful.  Do a find and replace all.  Look for the value “8A306″ and replace it with “8A400″.  Save and close the Buildmanifest.plist file.  Now look for a file called restore.plist.   Do a find and replace using the same values that you used before.  Save and close.

4. Now download the 4.0.2 update.  Once again it will come as a .ipsw file, and you will need to rename it .zip – open it, but DO NOT EXTRACT IT!!!!  Drag ALL the files from the package you just modified into the opened zip file archive.  You will see several dmg files that end in 002, delete them.

7. Save the zip file you just created, and rename the extension back to .ipsw – This is the file you will use to do the downgrade.

8. Now you need add a line to your hosts file.  For Windows users, go to \windows\system32\drivers\etc and open the file “hosts” in notepad.  Add the line “74.208.10.249 gs.apple.com” to the file (without the quotes), save and close. If you’re using a Mac then use Finder and click on “go to folder” and type /etc/.  Copy the hosts file to your desktop and open it with TextEdit and add the line to the end of the file.

After you modify the file, drag it back to /etc
Always save the file on your desktop and then drag it back into the folder “/ etc”

Save the file.

To restore the file you created you will need to put your iPhone in DFU (Device Firmware Update) mode, NOT Recovery Mode!!!!

Connect iphone to USB then listen to the sound when it connects and disconnects.

Hold the home and power buttons until you hear the disconnect sound then release only the power button, still holding down the home button.

Wait until you hear another sound then release home button.

If you’re still not sure how to put your phone into DFU mode, just look on youtube, there are thousands of videos that will demonstrate the process.

Once you are in DFU mode, browse to and restore the .ipsw file that you modified. 

This is going to be one of those things that works, or it doesn’t.  Make sure  you have a good backup of your phone before you do it.  Don’t call me if you FUBAR your phone.  If the procedure completes, and it probably will, you will be running IOS 4.0.1, and you will be running IOS 4.0.1, and you will be able to go to the Jailbreakme website and install the software including Cydia.  When you install Cydia, make sure you choose “let Cydia make my life easier” so that you will always be able to downgrade easily.  Jailbreakme website and install the software including Cydia.  When you install Cydia, make sure you choose “let Cydia make my life easier” so that you will always be able to downgrade easily.  Now you can enjoy all the fun of a jailbroken iPhone including free Tethering, multiple themes, etc.  Have fun! 

If you like this little hack, give me a link back!  Chuck Hoskins

Link Text – Chuck Hoskins