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  1. Thread AuthorThread Author   #1  
    megatronic's Avatar
    iPhone Nanite

    4 Posts

    Default how to downgrade version 4.2.1 to the previous version to unlock the AT&T carrier?

    I have iphone 4 version 4.2.1 with modem firmware 03.10.01 locked for AT&T I jailbreaked it successfully but i couldn't unlcok the carrier. moreover, I tryed to downgrade it but I should have SHSH saved with tinyumbrella-4.21.11 software where it is not available with me and i couldn't downgrade it.
    I want to now if there is a way to downgrade the version with out saved SHSH an unlcok my iphone.
  2. #2  
    Duvi's Avatar
    iMore Elite

    2,044 Posts
    Global Posts
    20,036 Global Posts


    i do not believe you can't d/grade w/o them being saved, but i could be wrong -- i haven't jailbroken since the 3GS. hopefully someone can confirm my statement.
  3. #3  
    thunderkeys's Avatar
    iPhone Beginner

    89 Posts
    Global Posts
    91 Global Posts


    There is no way to downgrade your modem firmware to an unlockable version for the iPhone 4. Can I Unlock My iPhone?
  4. #4  
    Ipheuria's Avatar
    iMore Genius

    7,265 Posts
    Global Posts
    7,332 Global Posts


    Like these guys have said you can't ever downgrade your baseband. You can downgrade your firmware but not the baseband. So you're gonna have to wait till 4.3 drops and hopefully there will be an unlock for the current baseband so whatever you do don't upgrade to 4.3 or the baseband might upgrade and it would be the same thing all over again.

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