How to Downgrade your Bootloader with ZiPhone (Windows)

Posted February 13, 2008 at 11:35pm by iClarified | Please help us and submit a translation by clicking here | 151832 views

Step by step instructions on how to downgrade your iPhone 4.6 Bootloader to 3.9 with ZiPhone instantly! No downgrading then upgrading!

To do this downgrade you must have restored your iPhone to 1.1.3 and then followed this tutorial to unlock:


Why would you still want to do this? The 04.03.13 baseband can be unlocked on 3.9 BL. This means you can have Google Locater working. Also, all old secpacks will not validate on 4.6. The 4.6 Bootloader requires a secpack of a newer version to let you do things with the baseband; whereas, the 3.9 BL requires the same version OR newer.

Perform these steps with your iPhone on and connected to your computer.

Step One
Download ZiPhone from: here

Step Two
Double click on your desktop to extract the folder ZiPhone..

Step Three
Press the Windows key and R at the same time to bring up the Run window. Type in cmd and press the Ok button to launch the Command Prompt.

Step Four
Type the following command into the Command Prompt to navigate to the ZiPhone directory:
cd Desktop/ZiPhone.

Step Four
Execute the command ziphone to see all its possible uses.

Step Five
The program will prompt you to put your iPhone into recovery mode. To do this please hold down both the Sleep/Wake and Power buttons until you see the Apple logo. Once the Apple logo appears release only the Sleep/Wake button until you see the iTunes logo and cable on the screen.

Step Six
If you have a 4.6 BL iPhone you can now downgrade your bootloader! Just simply type in this command:
ziphone -b -v

Step Seven
The program will now search for zibri.dat. Then it will search for the iPhone. Once found it will tell you to wait for 2 minutes and 30 seconds.

Step Eight
After this time your iPhone will reboot and it will be bootloader downgraded to 3.9 with the 04.03.13_G baseband!

NOTE*: After completion its probably a good idea to install BSD Subsystem first then OpenSSH from

NOTE*: If you are in an unsupported country YOU MUST patch AppSupport after unlocking or your dialer will keep crashing as will your SMS:

THANKS***: Big thanks go to Zibri for creating ZiPhone. You can link to his blog for updates: here

Add Comment
REUT - August 3, 2013 at 6:45pm
** ** Great site for permanent factory unlocks - sim free your mobile phone. It cost me only 7 usd!
pradip shrestha - May 29, 2009 at 11:40am
Download application in iphone there is not problem but its could not open
sudhir - December 11, 2008 at 3:56am
how downgrade baseband 2.1,i have upgrade 2.2 and re downgrade 2.1, now phone is locked , how i downgrade baseband
wombat - February 28, 2008 at 6:23pm
...using ZiPhone 2.4 it worked just fine. Now I have Bootloader 3.9_M3S2 and Modem Firmware 04.03.13_G. The APP Baseband Info says that I have Mode iPhone 1.1 although I\'m actually on 1.1.3. Guess it\'s the same. Everything works fine so far....... ----------------------------now waiting to upgrade to 1.1.4------------------
wombat - February 26, 2008 at 6:26pm
@iClarified: Meanwhile we are at ZiPhone GUI V 2.4....................I used the method in the previous tutorial, which did not have the option to downgrade the bootloader from 4.6 to 3.9. Now 1.1.4 is on the market.........My Q.: should those who did not use the option (as not yet available) to downgrade the bootloader in order to get to Firmware 04.03.13_G????? With 1.1.4 out it seems to make more sense now to downgrade to 3.9.....................
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