How to unlock iPhone 3GS on iOS 5.0 modem firmware (baseband) 5.16.05?
UPDATE: You can now unlock it for free, follow the steps here.
Firstly, please note that baseband 5.16.05 cannot be unlocked. Your only option is to update it to iPad baseband 6.15.00. Typically, you would use redsn0w to install iPad baseband on your iPhone. There are risks associated with the iPad baseband so be sure to read this first.
With the release of sn0wbreeze 2.8b10, it makes the whole process easier to jailbreak and unlock your iPhone 3GS.
The custom firmware that you’re about to download below was created using sn0wbreeze and the iPad baseband is already included in the package. Ultrasn0w and MobileSubstrate (software to unlock iPhone) have been included as well.
The instructions below will guide you through the whole process.
Warning: Proceed at your own risks!
1. Download the latest iTunes from Apple’s website and install it. Remove your SIM card.
2. Download custom iOS 5.0 (already hacktivated, jailbroken):
- iPhone 3GS with new bootrom + baseband 6.15.00 included + ultrasn0w installed
- iPhone 3GS with old bootrom + baseband 6.15.00 included + ultrasn0w installed
4. Launch iBooty and follow on-screen instructions on how to pwn-DFU your iPhone. If you use redsn0w, go to Extras -> Pwned-DFU and follow on-screen instructions.
5. Once you have pwned DFU your iPhone, launch iTunes. Click Shift+Restore and point it to the firmware you just downloaded in Step 2.
6. iTunes will begin restoring so just wait until the process is finished. If you get error 3194 during restore, read here.
7. When restore is complete, you will find that you now have iOS 5.0 and baseband 6.15.00.
8. Disable 3G and Cell Data by going to Settings -> General ->Network. Insert your SIM card and your iPhone should connect to your network.
Post unlocking – iMessage not working? Try this.