The unlock solution (codename “yellowsn0w”) of iPhone 3G has been released a couple days ago. This’s really a great news and a big start for 2009. Big thanks to iPhone Dev Team. Many of you may have already tried to use yellowsn0w to unlock iPhone 3G. As I received quite a number of emails from readers that they are not very sure the exact procedures to handle the unlock, I design to write up a detailed how-to.
Okay, here comes to the step-by-step guide for iPhone 3G unlock. iPhone Dev Team has already made the unlock simple by using Cydia. This guide just re-organizes all the important hints/stuffs and procedures, so I hope any novice can handle it.
Let’s get started to unlock iPhone 3G.
Get Prepared – Jailbreak iPhone 3G
As the unlock application only works on baseband 2.28.00 and jailbroken iPhone, there are a couple of things you get to prepare before going ahead to download yellowsn0w.
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Have you jailbroken your iPhone and upgraded to firmware 2.2? The unlock application “yellowsn0w” can only work on jailbroken iPhone as you’ll need to use Cydia to download the unlock application. And the unlock can only work with firmware 2.2 baseband. So, if you haven’t done that, please follow this jailbreak guide (using QuickPwn) to jailbreak the iPhone first. Ensure you’re using the QuickPwn 2.2 and download firmware 2.2 in the jailbreak process.
For Mac user: Even if you have jailbroken your iPhone using PwnageTool 2.2, please do use QuickPwn 2.2 for Mac to jailbreak again. The reason for a 2nd jailbreak is that PwnageTool 2.2 doesn’t upgrade the baseband to 2.28.00. So, please follow the same QuickPwn guide. The procedures are very similar but you have to use QuickPwn 2.2 for Mac. You can download it here.
- Next, check iPhone 3G baseband version: Go to Settings -> General -> About and look for “firmware version”. It should be 2.28.00. (Even you’re sure about the baseband version. Please do check again before going to the unlock procedures)
No PIN support yet: Please disable any PIN on your SIM card in case you have any before using yellowsn0w.
Note: If your baseband version is 2.30.00 or up, you may consider using 3G Fuzzyband Downgrader to downgrade the baseband
Real stuffs – Unlocking iPhone 3G
Before you go ahead to download yellowsn0w and unlock iPhone 3G, let me put it straight. You’d use the unlock application at your own risk. As mentioned by iPhone Dev team, the unlock application v0.94 v0.95 is in beta and it’s impossible to test the unlock with all SIM cards & carriers. So, there’s a chance the unlock solution does not work for you.
You can follow these procedures to unlock iPhone 3G.
1. Press “Cydia” to launch Cydia from iPhone home screen
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2. Next, you’ll have to add the download source of yellowsn0w. Tap “Manage” and then “Source”.

3. Tap “Edit” and then “Add” button. You’ll be prompted to add a new Cydia/APT URL. Type “http://apt9.yellowsn0w.com” and tap “Add Source” button. Wait until Cydia prompts you the complete message and tap “Return to Cydia”.


4. Next, tap “Done” and then tap “apt9.yellowsn0w.com” from the list of sources.

5. You’ll then find the “yellowsn0w” application for download. Tap on it and then tap “Install”. Then tap “Confirm” to start download. (Note: The latest version of yellowsn0w is 0.95 beta)

6. Once the installation is complete, tap “Return to Cydia”. And then press “Home” Button to go back to the home screen.
7. It’s almost to complete the unlock process. Next, you can press the “Sleep” button and hold it off until you see the “slide to power off” message. Then slide to switch off the iPhone.

8. Wait until your iPhone completely shutdown. Now make sure you have inserted your desired SIM card in iPhone and turn on your iPhone.
Tips: If you do not know how to remove SIM card, you can refer to this article from Apple support for details.
9. Once your iPhone boots up and you see the “Slide to Unlock” screen, wait for around 15 seconds (may be more) and your iPhone will pick up the signal of the carrier.
10. If there is no signal pop up, try to pull out the SIM card and re-insert it. Wait for another 15 seconds and see if this works.
11. Cool! Now, your iPhone 3G is unlocked! You should now be able to make calls with your desired carrier.
Important Points for Unlock
- After you go through all the steps and it still doesn’t work, try to toggle “Fly Mode”. You can go to “Settings” -> Turn ON Fly mode. Then switch it off again. This may help to pickup the carrier signal.
- Also, sometimes, a network reset will make the thing works. You can go to “Settings” -> “General” -> “Reset” -> “Reset Network Settings” to reset the settings. After that take out the SIM and re-insert it, see if this works.
- If you’re in US and using T-mobile, you’ll need to turn off “3G” in Settings to make the unlock work.
- No PIN support. Please disable any PIN on your SIM card in case you have any before using yellowsn0w.
So, it DOESN’T WORK. What else can you do?
Okay, you have tried out all the above procedures and hints. But the unlock is still not working on your iPhone 3G. First, don’t be frustrated and angry. Please accept that yellowsn0w is still in beta and it’s not an easy task for iPhone Dev Team to make it work for all SIM cards and carriers in the world. iPhone Dev Team is working very hard to fix bugs and releasing update to make the software work for you.
So, what else can you do?
- At the mean time, you may uninstall yellowsn0w from Cydia and use back the SIM card from the official carrier. And wait for the next update of yellowsn0w. I’ll always keep you informed once the update is available.
- Oh, you won’t give up and want to have a 2nd trial. That’s ok. You can always try to pull out the SIM card and re-insert it again for any number of times. That won’t harm.
- Finally, you can ask for help. You can consult the iPhone Dev Team blog for help. Or you can leave comment here and other readers that came across a similiar problem, may help.
No matter it works or not, I’m glad you can leave us comment (specifiying your SIM carrier and country) and tell us whether the unlock is a success. Good luck for your iPhone 3G unlock!




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