Upgrade Iphone 4 on 4.0.2 to 4.2.1 - Help Please!

Discussion in 'Jailbreaks and iOS Hacks' started by Ch1lly, Mar 31, 2011.

  1. Ch1lly macrumors newbie

    Mar 31, 2011
    I have recently purchased an iPhone 4 which is currently running 4.0.2, now i want to update it to 4.2.1 (the latest firmware to which you can jailbrake)

    Now i have downloaded many versions of the 4.2.1 ipsw from various sources but when i attempt to update the iphone, itunes will extract the file as normal and begin verifying the update with apple.

    Now the problem comes in the form of a dialog box saying 'this device is not eligable for the selected build'

    this error has occurred on both the 4.2.1 ipsw and the 4.2.0 which i have tried, i have tried more than one version of it and i cannot get it to work!
    iTunes is up to date, the phone has been synced and activated, the phone works fine (it is not in DFU mode or anything like that)

    Is it something really simple that i am missing or is it just not possible to do this after 4.3.1 has been released???

    Please if anyone could help it would be really appreciated!

  2. nebo1ss macrumors 68030

    Jun 2, 2010
    All firmware restores must be signed by apple. They will only sign the lastest release which is presently 4.3.1.

    There is a work around method which uses SHSH blobs to fake out the signing. If the person you bought the phone from had been saving SHSH blobs then you can use them to do what you want.

    Download an application called Tiny umbrella "Google It" launch it and plug your phone in and select save SHSH. It can only save the latest but if the previous owner had been saving SHSH then it will get them from Cydia.

    See what you get and you can restore only to the latest or to any version for which you have SHSH blobs.

    You might also want to check what baseband you have on that phone. If you have 1.59 that means the baseband can be unlocked to use with any carrier. IP4 with baseband of 1.59 are like gold dust and are the only version that can be unlocked. If you do have the SHSH blobs and you are going to upgrade you might want to consider using custom firmware which will save the existing baseband. Even though you may not need the unlock the phone is more valuable if you can unlock it.
  3. Ch1lly thread starter macrumors newbie

    Mar 31, 2011
    Right, that has pretty much summed up what i was thinking. i am not too bothered about physically unlocking the phone, as it's already on my network.

    Looks like i'll have to stick to 4.0.2 then... hey ho!
  4. sbddude macrumors 6502a

    Sep 27, 2010
    Nor Cal, USA

    If you have unlockable baseband, it would be beneficial to keep it, even if you don't need the unlock. If/when you sell the phone, or if you ever need to travel internationally, it will be nice to have.

    In your position I would check the TinyUmbrella to see if SHSH are saved, and if they are, you can build a custom firmware with preserved BB and restore to 4.2.1.

    If you don't have SHSH, then just stick with 4.0.2 until the untethered 4.3.1 jailbreak is released. Then do the custom firmware/preserved baseband.
  5. vexatia macrumors regular

    Aug 9, 2008
    Apologies for the nub question, but I've been out of the jb loop since 4.01.

    I currently have a jailbroken IP4 running 4.0 on bb 1.59.00 with shsh blobs saved through Cydia for 4.01, 4.02, 4.1, 4.2.1 and 4.2b3. I would like to upgrade to the highest possible iOS on which I could retain an untethered jb and unlockability. If I've researched correctly, I believe that I could use pwnage tool 4.2 (I'm on a mac) to upgrade to 4.2.1, while preserving unlockability and an untethered jailbreak.

    Could someone confirm?
  6. Crystal-RX macrumors 68030


    Dec 22, 2008
    Seattle, WA USA
    Yes, you can do that. Currently, 4.2.1 is the latest you can go with untethered jailbreak.

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