If you are in a position where you can’t unlock your iPhone 3G with ultrasnow, well we have just the solution for you. Here is the method to downgrade your baseband from 06.15.00 to 05.13.xx which will allow you to unlock your device by using Ultrasn0w.
By doing so you can also restore your device to the original firmware that came when it launched. This method only works for iPhone 3G (bootloader 5.8) for now. Do not ever forget to backup your data when ever trying to jailbreak or doing any sort of stuff like this of course.
Necessities to downgrade the baseband:
- Jailbroken iPhone 3G
- Fuzzyband installed via Cydia
- afc2add installed via Cydia
- i-FunBox (for Windows) or DiskAid (for Mac)
- Certificate to use with Fuzzyband.
Now here is the complete guide:
STEP 1: First of all you will need a certificate file ICE-06.15.00.cert. Download it from here.
STEP 2: Install the Fuzzyband that you just downloaded.
STEP 3: Now it’s time to connect your iPhone 3G with computer.
STEP 4: Install i-FunBox that you downloaded before starting the STEP 1and click on File. Now go to Application, Fuzzyband.app, right click and then select copy from PC.
STEP 5: Copy the file ICE-06.15.00.cert to the location Application/Fuzzyband.app.
STEP 6: Simply disconnect the iPhone from PC and run the Fuzzyband in your iPhone.
STEP 7: You can see the current version of baseband by using Fuzzyband. At stat it should be 06.15.00 but don’t hold your breath. You will have option to downgrade it right there.
One you are done with downgrading them simply click on “Setting” and then “About” now scroll down and see what the baseband is.