Downgrade iPad Baseband on iPhone 3G to Unlock.
The process is risky and you will follow it at your risk. We assume no responsibility. Backup your data before iPhone restore.
Please read carefully this page to understand if really need to flash the iPad Baseband on your device to unlock it. Unlock iPhone3G
You need this tutorial only if you have 06.15.00 baseband on your device.
You could do all the steps manually but we provide you a really easy way to install the iPad Baseband on your iPhone 3G.
All Whited00r users (or not) with an iPhone 3G who upgraded to the iPad 06.15.00 baseband can downgrade back to a regular iPhone baseband. In this short guide you will learn how to downgrade your baseband from 06.15.00 to 05.12.01 (but you could get 05.13.04 using a different firmware for the rollback) with a lot of benefits: GPS will work fine, you will solve the problem of battery drain and you will get better signal.
This tutorial is quite long and there could be other ways to downgrade the firmware in a faster way, but we would like to offer a working and easy method.
Restore to iOS4.2.1
Download and install this firmware we prepared your iPhone 3G with the iPad Baseband: this will install the iPad baseband on your device.
Open iTunes on the screen about your device. Click on Restore holding ALT (MacOS) or SHIFT (Windows) at the same time and select the special firmware you can download in this step from you computer. Can't you install?
Your iPhone 3G will run iOS4.2.1 with 06.15.00 iPad Baseband at the end of this step: check the "Version" and “Modem Firmware” in Settings –> General –> About. If everything is ok, please move to the recycle bin this firmware: we don't need it anymore and you could confuse with other.Download: Firmware with iPad Baseband
Download Apple Stock Firmawres.
Please download both the iOS4.2.1 and 3.1.3 firmware for iPhone 3G. We will the first one with Redsn0w tool in the next step, and the second one will be used to inject and old baseband (iOS3.1.3 will install 05.12.01 that is fully unlockable with Ultrasn0w).
Download from this page both iOS4.2.1 and iPhoneOS 3.1.3 for iPhone 3G. Download Original Firmware
Downgrade with Redsn0w.
Download Redsn0w 0.9.14b2 for OSX or Windows.
Redsn0w for OSX: Download Keep pressed "Ctrl" on Mountain Lion OSX while click on the app
Redsn0w for Windows: Download Run this tool as "Administrator Mode"
Open Redsn0w and select “Extras” then “Select IPSW”. Select the Stock iOS 4.2.1 firmware you downloaded in the step previous step. Do a controlled shutdown of your iPhone (“slide to power off”): this step is very important to avoid mount problems. On Redsn0w click “Back” and you will see the initial window. This time click on “Jailbreak”.
Enable “install Cydia” and “Downgrade from iPad Baseband” checkboxes. Click “next” and “next” to proceed through the normal DFU steps
The flashing process will begin: don't touch the device and don't disconnect the USB cable. It may take up to 10 minutes.
After this process check the “Modem Firmware” in Settings –> General –> About. You should see that your baseband information are missing (seems that your baseband is broken, but it isn't: we just need to load the basaband that your prefer: in this tutorial we will install 05.12.01 using iPhoneOS 3.1.3 stock firmware.
Restore to iPhone OS 3.1.3.
Open iTunes on the screen about your device. Click on Restore holding ALT (MacOS) or SHIFT (Windows) at the same time and select the iPhoneOS 3.1.3 you downloaded two steps ago. Can't you install?
Your iPhone 3G will run iOS3.1.3 with 05.12.01 Baseband at the end of this step. The problem is that maybe you can't check it because iTunes will ask you activation and you may not have the legit sim card needed for activation. Anyway, we will discover it really soon! You just need to install an unlocked firmware (like Whited00r) to finish this tutorial and start using your device.
This is the final step, but is required to use your device. Install Whited00r for iPhone 3G, unlocked edition following the normal installation guode. iPhone 3G Whited00r Download.
You could install any unlocked firmware, not only Whited00r: but be sure that the firmware your are going to install does include the "preservation baseband". For this reason please don't install Apple stock firmwares, otherwise your baseband will be upgraded again and you will send a lot of time to rollback it.
Your iPhone 3G will run Whited00r with 05.12.01 Baseband at the end of this step. Your baseband is fully unlockable with Ultrasn0w and you will solve all problems that the previous 06.15.00 iPad Baseband was giving.