This is really an awesome news for those who have upgraded to iOS 4.0.2 and want to downgrade it back to iOS 4.0.1 to take advantage of JailbreakMe (as the iPhone Dev Team is not planning to release a jailbreak tool for iOS 4.0.2). Until now, it is only possible if you have saved SHSH Blobs for iOS 4.0.1. But, it looks like there is a possibility of downgrading from iOS 4.0.2 to iOS 4.0.1 or iOS 4.0 with out SHSH Blob. With that said, lets not waste any more times and get started. Let us know if this work around worked for your.

Warning: Please do it on your own risk. We will not be responsible for any damage or breakage of your iPhone.

Step 1:

Download iPhone Firmware Version (iOS 4.0.2 & iOS 4.0.1/ iOS 4.0)

Step 2:

Now, extract the ipsw file that you have just changed using WinRaR

Step 3:

Open the Buildmanifest.plist with Notepad.

Step 4:

Now, Click “Control” + “F” to get the Find Windows

Step 5:

Here, Find and replace all “8A306? (if you are using iOS 4.0.1)/ “8A293? (if you are using iOS 4.0) with “8A400?.

Step 6:

Now, Open the Restore.plist with Notepad

Step 7:

Now, Click “Control” + “F” to get the Find & Replace Windows.

Step 8:

Here, Find and replace all “8A306? (if you are using iOS 4.0.1)/ “8A293? (if you are using iOS 4.0) with “8A400?.

Step 9:

Now, take the iOS 4.0.2 firmware file, rename its extension from .ipsw to .zip

Step 10:

Extract the iOS 4.0.2 file that we have just rename its extension and leave it open.

Step 11:

Now, move all the iOS 4.0.1 / iOS 4.0 files to iOS 4.0.2 windows (Folder that we have open in Step 11)

Step 12:

Once moved, Delete all the dmg files that have 002 at the end, leaving only the 001 files left and Close this windows.

Step 13:

Now, Change the iOS 4.0.2 firmware extension to .ipsw from .zip

Step 14:

Navigate to the following folder “C:\Windows\System32\drivers\etc

Step 15:

Now, look for the file name hosts and open it with Notepad

Step 16:

Add the following line at the bottom of the file (if you have in the file comment it out by adding # in front of the line)

Step 17:

Now, click on File and select Save

Note: To double check if you updated the hosts file – Open one more terminal window and type “ping” you should get some thing like this ..

  • PINGING []: 32 data bytes of data:

Step 18:

Now, grab your iPhone, plug it in and lets put your iPhone into DFU mode.

  • Here, iTunes will alert your that “iTunes has detected an iPhone in recovery mode. You must restore it before it can be used.” Click okay

Step 19:

Now, it time for us to restore the firmware – Hold down the “SHIFT” key and click on “Restore“.

Step 20:

That’s it! Now, you can just sit and relax and let the restore finish.

Related posts:

  1. How To Downgrade Your iPhone From iOS 4.0.2 To iOS 4.0.1/iOS 4 Without SHSH Blobs [Mac]
  2. How to Downgrade Your iPhone 3GS Using a Cydia Saved SHSH [Windows]
  3. How to Backup Your SHSH Blobs Using Firmware Umbrella [Windows]
  4. How To Downgrade iOS 4.1 to iOS 3.1.2/3.1.3/4.0 On iPhone 3GS[Windows/Mac]

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