As we posted, the Dev Team has produced RedSn0w 0.9.14b1 today. The updated edition of the most-known iPhone jailbreak software features the very-expected ability to downgrade 6.15.00 to 5.13.04 baseband for iPhone 3G / 3GS. Users with unlocked 3G / 3GS iPhones stuck on 06.15.00 ipad baseband are now able to downgrade to 05.13.04 baseband.
How to Downgrade Baseband 06.15.00 to 05.13.04
If their iPhone's baseband will be downgraded that mean that their GPS will be restored and their device with downgraded baseband will be supported with Ultrasn0w 1.2.7.
iPhone Dev Team's release information:
"The iPhone Dev Team is happy to announce a baseband downgrade option in redsn0w for those who are using the iPad's o6.15 baseband on the iPhone3G or iPhone 3GS.
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:
Step 1. 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).
Step 2. 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!
Step 3. 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 it's 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 is not compatible with 3GS units manufactured week 34 of 2011 or later. If you have an iPhone 3GS 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!"
How to Downgrade Baseband 06.15.00 to 05.13.04 With Redsnow
Step 1: Download Latest Redsn0w.
Step 2: Start Redsn0w.
Step 3: Connect your iPhone to the Computer and Put it into DFU mode.
Step 4: Now click "Jailbreak", Select "Downgrade from iPad baseband", unselect Cydia in the event that you previously have installed it, Now click Next, and wait right up until you view the "Flashing Baseband" message.
Keep refresing UnlockBoot for more, soon we will post a video guide on how to downgrade baseband 6.15.00 to 5.13.04 using Redsn0w. For anyone who definitely are ready to begin, you can download Redsnow 0.9.14b1 from our Downloads section.
Any thoughts? — Hit the Comment section below!