Downgrading & unlocking iPhone OS 3.0 (updated)

18 Mar

Just a quick note with more details in a few hours:

Apple’s iPhone OS 3.0 Beta pre-installation advisory document states that once you’ve updated a device it’ll be in a “locked state” with no way of going back to an earlier firmware.

While this might be perfectly true for regular iPhones it has not been the case for one of my first generation development devices. I’ve been able to do the following:

  • Restore (not update!) to Beta 3.0
  • Downgrade by restoring back to 2.0 via iTunes
  • Jailbreak and unlock by using QuickPwn to custom 2.0 built
  • Update  (not restore) to Beta 3.0

This particular device is now running perfectly on the Beta 3.0 release with unlock working fine – Cydia and Installer are obviously gone, as it has always been the case when applying updates.

To avoid confusion: I’m not aware of any solution, yet, that allows to jailbreak/unlock an iPhone running the current beta of OS 3.0. I did the following: I restored a first generation (not the 3G!) iPhone to the default Apple Firmware 2.0. I then used QuickPwn on a Mac to jailbreak and unlock. This gives me an unlocked iPhone 2G with Firmware 2.0. I then updated to the regular 3.0 Beta via iTunes.

The unlock is preserved, so the update seems to not wipe the modifications done on the 2.0 version. Effectively I’ve now got an unlocked iPhone 2G running OS 3.0 Beta. Cydia and Installer are gone (always happens during updates) but jailbroken apps still run!

Important Note:

Everybody: While it might be legal, I cannot actively support people buying iPhone Dev Portal UUID registrations through my web site. :-)

I’d therefore kindly ask to not submit any new comments related to paying others for getting registered to their iPhone Dev Programs.

I leave comment moderation turned off for the moment but will clear all future comments which do not obey this rule. Had to turn comment moderation on because some readers could not resist to continue to post UUID adding offerings. Sorry. Once everybody has calmed down, I’ll switch it off again.

Hope this clarifies things.

Note: I generally do not encourage jailbreaks or endorse unlocking hacks. I run one of my development devices jailbroken and unlocked in order to make sure, that my App Store software works on these modified devices, too.

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103 replies
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  1. Chris M says:

    OK, I hope my experiences with 3.0 can help those of you with semi bricked iPhones out:

    1. I ran the 3.0 update on my stock iPhone 3G. (2.2.1 firmware no jailbreak). It wouldn’t activate as I don’t have my ADC license through yet.

    2. I ran the 2.2.1 restore and it failed at around 60-70% on the progress bar

    3. I used quickpwn on the PC to liven the iPhone up again but there was no cell signal.

    4. I used PwnageTool on the Mac to create a custom firmware without cydia, installer and with activation turned off (my iPhone is on O2).

    5. I used iTunes on the Mac to restore using this firmware, iTunes activated the iPhone and now it gets a cell signal again.


    You cannot restore using a stock 2.2.1 firmware and get the iPhone working fully after running 3.0. The reason for this is that 3.0 upgrades the baseband to 04.20.01 and the 2.2.1 firmware does not recognise it as a valid baseband.

    Warning: If you use a stock 3.0 upgrade it will overwrite your baseband and may cause you problems in unlocking your handset in future.

    Hope this helps.

    • EthanHolmes says:

      What version of iTunes do you use?
      And also, do you think this would work on AT&T?

  2. Noclaf says:

    I’m sorta new to all of this, but I signed up for the developer program so I could upgrade and “bricked” my phone too because I got sidetracked and forgot to add the UUID on the DEV website…After trying to downgrade without success ao that I could see the UUID in iTunes, I decided to try and find it in a file somewhere on the PC. I use a PC, not a MAC. I found it in the “info.plist” file under my profile in Application DataApple ComputerMobileSyncBackup. The folder name is also the UUID. I added it and it registed! You might all know this already, but I didn’t !!

  3. ithoo says:

    Hi all. i have iphone 16gb ( 2G ).
    i want to upgrades os 3.0.
    How can i do….?
    can any body help me

  4. ralf.rottmann says:

    Ladies and Gentlemen, please do no longer post comments offering to sell your iPhone Dev Program UUID slots. I’m not going to approve these kind of comments. Thanks.


  5. Hami says:

    Bricked my phone. I’m a developer, but after updating to OS 3.0 beta..My phone is stuck. Think I missed the UID register thing…
    Please somebody help.
    Have iphone 3g with at&t

  6. Hami says:

    Im doing the same thing in xcode and it says

  7. luke says:

    I am using a different sim card, one that has not been agreed with apple. I am just wondering, I have join the developer site and paid the $99. Now waiting for my access code. once i get it do you think everything will be ok or would i need to use it with a valid sim card? I’ll be more than happy to give a few access to my slots. […]

    Edited to apply to our “don’t sell iPhone Dev Program slots”-policy!

  8. tien says:

    please looked here “How to install your iPhone 3.0 OS beta on your 2G device’

  9. C. Lonie says:

    3.0 MMS and tethering is working here … UK on O2… If you need help getting these services working please let me know …

  10. Matt says:

    Im registered on the Iphone developer program and i have downloaded the relevant files.

    Is there anyway of using my windows vista based pc to install the new updates onto my iphone?
    or does it have to be a mac?


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