iPhone Dev team has just released a new version of their jailbreaking software Redsn0w. The new version of RedSn0w is 0.9.14b1 and it brings functionality to downgrade iPhone 3GS/3G baseband 06.15.00. This is the baseband on which many users were stuck for a long time.
Before the release of RedSn0w 0.9.14b1, the only way to unlock your iPhone 3G/ iPhone 3GS was using UltraSn0w and upgrading to the iPad baseband 06.15.00. However, this moving to this baseand also causes many problems for the iPhone 3G/iPhone 3GS users like their GPS did not function and they couldn’t use stock IPSW. Users can now downgrade to baseband 05.13.04, keep the unlock and not face any issues.
The iPhone Dev Team is happy to announce a baseband downgrade option in redsn0w for those who are using the iPad’s 06.15 baseband on the iPhone3G or iPhone3GS.
Typically you’d have the 06.15 baseband if you unlock with ultrasn0w but updated your iPhone baseband past 05.13.04. With this new capability, you can now downgrade specifically from 06.15 to 05.13.04 (even if you never had 05.13.04 on that device before). This gives you the best of both worlds: ultrasn0w compatibility and a normal iPhone baseband with full GPS and the ability to use stock IPSWs again.
Here are the steps:
Use the “Extras->Select IPSW” button in redsn0w to tell it which firmware version you have installed (new-bootrom 3GS users can usually skip this step but it doesn’t hurt for them to do it too).
Do a controlled shutdown of your iPhone (“slide to power off”). This step is very important to avoid mount problems when the ramdisk is running!
Go back to the first screen and click “Jailbreak”. Enable the “Downgrade from iPad baseband” checkbox, disable Cydia if you already have it installed, and click Next to proceed through the normal DFU ramdisk steps.
After the ramdisk gets launched and you see the Pwnapple running on your iPhone, you’ll eventually get to the “Flashing Baseband” step. THIS STEP TAKES A VERY LONG TIME to complete and there won’t be any feedback while its running. Please just let it be for the next 3-8 minutes! When the ramdisk has done its job it will reboot the phone on its own.
For those who are wondering if you can update your 3G or 3GS to 06.15 solely for the purposes of downgrading to 05.13.04, the answer is “yes” for 3G owners, and “maybe” for 3GS owners. The iPad baseband is not compatible with 3GS units manufactured week 34 of 2011 or later. If you have an iPhone3GS and if digits 3-5 of its Serial Number are 134 or later (xx134…), then you should NOT try to install the 06.15 baseband on your 3GS! It will brick your radio, preventing both the downgrade from working and normal iPhone software from using it as a phone! Be warned!
Downgrade iPhone 3GS/3G Baseband 06.15.00 With RedSn0w 0.9.14b1