Guide To Unlock iPhone 3G (2.2.1 Firmware) Using Yellowsn0w

This is a good news for iPhone 3G users who do not intentionally upgrade to this version of firmware (Quick tip: It’s always good for you to turn off auto-upgrade in iTunes) and are searching for ways to unlock iPhone. Here I try to show you a solution for that. But, before read on, please note that this solution does not fit for all iPhone 3G. It's specially for unjailbroken iPhone 3G and 2.2.1 firmware users only.

Let me remind you here, "unlock" word is refer to the process to open up your iPhone to accept all carriers. Unlocked iPhone allows you to use SIM card from all carriers. You are no longer bind to the official carrier (e.g. AT&T) approved by Apple. And for, "jailbreak" your iPhone means you are allowed to install 3rd party applications on iPhone. Its mean to say that, this guide only instruct to you about unlocking iPhone 3G 2.2.1 firmware.

Baseband Problem..

Presently, there is no easy way or software to unlock this version of firmware. To be exact, there is no unlock solution to tackle the baseband v2.30.03, which is upgraded together with firmware 2.2.1. The latest version of yellowsn0w, the iPhone 3G unlock solution, doesn’t support iPhone with baseband 2.30.03 or up.

The Solution..

Thanks to the jailbreak community. iPhone developers have created a simple tool called “3G Fuzzyband Downgrader” to downgrade the baseband from 2.30.03 to 2.28.00. By downgrading the baseband, you can then use Yellowsn0w to unlock the iPhone. However, there is a catch. The downgrade utility only supports iPhone with bootloader v5.8. Don’t worry if you do not know your bootloader version. The downgrader will handle the checking for you. But if you’re not using this bootloader version, I’m sorry that there is currently no software solution to unlock your iPhone 3G. You can either wait for iPhone Dev team to develop the solution or you can opt for SIM-card based unlock.

Step 1: Follow this step-by-step guide to jailbreak your iPhone 3G with firmware 2.2.1. Before your start to jailbreak backup you iPhone data synchronizing it with iTunes. You may see an instruction on how to backup your iPhone.

Step 2: After jailbreak, go to Cydia and download “3G Fuzzyband Downgrader”. You may read an instruction on how to downgrade iPhone 3G baseband using 3G Fuzzyband Downgrader.

Step 3: With the baseband downgrade completes successfully, you can use Yellowsn0w to unlock your iPhone 3G. The yellowsn0w can be downloaded freely via Cydia. For details, you can refer to my post on "Guide to unlock iPhone 3G (2.2) using Yellowsn0w". Bear in mind before your start to unlock using Yellowsn0w, please skip Step 1 and Step 2 , you should start to unlock at the step 3.

I hope this guide can benefit those who got the iPhone locked after firmware 2.2.1 upgrade. But let me emphasize again. The above instructions can only work for iPhone 3G with bootloader 5.8. Good luck!