How to downgrade to 4.2.1?

Discussion in 'Jailbreaks and iOS Hacks' started by busybee, Apr 15, 2011.

  1. busybee macrumors newbie

    Joined:
    Sep 9, 2010
    #1
    My apologies if this topic has a thread already but I've tried searching and didn't find anything that suited my needs.

    I've a non-jailbroken 3Gs running on the battery sucking iOS4.3.1. From what I've read, the new update doesn't solve the ridiculous battery drain. I want to downgrade my 3Gs back to iOS 4.2.1 which I still have the "iPhone2,1_4.2.1_8C148a_Restore.ipsw" file that was moved to the thrash when I upgraded to 4.3.

    Is it possible to restore it back to 4.2.1 with the above mentioned file & if yes, how?

    Thanks in advance.
     
  2. PsstGreek macrumors 68040

    PsstGreek

    Joined:
    Oct 21, 2010
    Location:
    Tampa Bay
  3. Grayburn macrumors 68000

    Grayburn

    Joined:
    Jul 12, 2010
    Location:
    London, England
    #3
    But he has a non-jailbroken handset so theres no chance of Busybee having them.
     
  4. maturola macrumors 68040

    maturola

    Joined:
    Oct 29, 2007
    Location:
    Atlanta, GA
    #4
    not 100% true, you don't need to be Jailbroken to have your SHSHs saved. (however chances are that he doesn't have them).
     
  5. busybee thread starter macrumors newbie

    Joined:
    Sep 9, 2010
    #5
    Correct, I didn't save them. Don't even know how to or what exactly it is:(:(.
    But thanks for answering. At least I know now.:eek:
     
  6. maturola macrumors 68040

    maturola

    Joined:
    Oct 29, 2007
    Location:
    Atlanta, GA
    #6
  7. optophobia macrumors 6502a

    optophobia

    Joined:
    Oct 26, 2007
    Location:
    Hudson MA
    #7
    before downgrading, do a full restore of 4.3.1 and rather than restoring from back up, set up as a new iphone.

    Yes you will have to do all your settings manually again, but if you have your contacts saved through google or on your sim, then you wont have to reenter them.

    That has been said to stop the battery draining issues (for SOME people)
     
  8. Applejuiced macrumors Westmere

    Applejuiced

    Joined:
    Apr 16, 2008
    Location:
    At the iPhone hacks section.
    #8
    Run tinyumbrella to see if it can pull your 4.3.1 blobs but not sure if Apple is still releasing them.
    If not wait for the untethered 4.3.2 JB.
     
  9. oplix Suspended

    oplix

    Joined:
    Jun 29, 2008
    Location:
    New York, NY
    #9
    i just had my iphone replaced. the replacement had 4.3 on it. Tinyumbrella said it had 4.2.1 shsh blobs for this new phone so i downgraded and it worked.

    on 4.2.1 with untethered jb.
     
  10. Steve99 macrumors member

    Joined:
    Mar 11, 2011
    #10
    Do you have baseband 04.10.01 or 03.10.01 and if you make a phone call and the other person hangs up first does the phone display "called ended" or "call failed" ?
     
  11. Crystal-RX macrumors 68030

    Crystal-RX

    Joined:
    Dec 22, 2008
    Location:
    Seattle, WA USA
    #11
    You received a refurbished one from Apple.
     

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