can i downgrade firmware iphone 3G w/ 4.0.2 to 3.1.3?

Discussion in 'Jailbreaks and iOS Hacks' started by latebloomer, Aug 25, 2010.

  1. latebloomer macrumors newbie

    Joined:
    Aug 25, 2010
    #1
    i've been searching and attempting for days, but i'm stumped. i've been hesitant to post here but im running out of patience.

    i know it's not possible to JB iphone 4 w/ 4.0.2, but is it possible to to DOWNGRADE iphone 3G w/ firmware 4.0.2 to 3.1.3 and then JB it? some imply it is possible but i cant seem to get it.

    i've downloaded 3.1.3 restore ipsw, put my phone in DFU mode and tried recboot but it keeps coming back to life with the same 4.0.2 firm :mad:

    i got this 3G phone secondhand with 4.0.2 already installed. i don't have access to any backups or shsh (that i know of).

    sorry to bother, but if anyone can help me DOWNGRADE my 3G from 4.0.2 to 3.1.3 i would greatly appreciate it. this is my first iphone. i've waited a long time to get my hands on one without having to go to ATT, and i don't want to do the wrong thing and end up bricking it.

    thanks for your time!

    powerbook g4 (osx 10.5.8) / itunes 9.2.1 / 8gb iphone 3G (NOT a 3Gs!)
     
  2. celticpride678

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    Boston, MA
  3. latebloomer thread starter macrumors newbie

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    Aug 25, 2010
    #3
    not that i know of.
    i'm really new to this and not sure.
    wouldn't the original owner who upgraded the firmware have those?
    i know he did a wipe of the phone and then i think he set it up as a new phone through his itunes before he gave it to me.
     
  4. Zodiak macrumors regular

    Joined:
    Jun 9, 2010
    Location:
    Gatineau, Qc, Canada
    #4
    You would have had to have clicked on Yes to save your SHSH file from within Cydia, on the homescreen WHILE you were initially on 3.1.3 or 3.1.2 (if you were initially)

    Apple signs their firmware with different versions and you need proof that you were once using that firmware using your previous SHSH file which is saved on Saurik's server from Cydia when you click on Yes.

    You can download a software called TinyUmbrella, connect your device via your 30pin connector to your computer and then you can have it retrieve what SHSH file was last saved to you on the server.

    Unfortunatly its not possible to retrieve previous SHSH files that were not saved to and you can only downgrade or restore to the firmware your SHSH file is saved for.

    When your ready to restore, connect your device to your 30pin connector, launch TinyUmbrella, connect to the server and then put your device into DFU Mode (where your device appears to be off though its not) not Recovery mode (the one with the CD and cable on the screen) then launch itunes, click the notification, then hold SHIFT and click the lower of the two buttons iTunes presents you with and then find the firmware version your SHSH file was saved for.

    TinyUmbrella will notice that iTunes is looking for a signature and will provide it your SHSH file. iTunes will find the signature and proceed to retore to the firmware you indicated.
     
  5. WhatAmI macrumors 6502a

    WhatAmI

    Joined:
    Sep 2, 2009
    #5
    Guys guys, we're talking about a 3G here. Not a 3GS so no need for SHSH's

    The process to downgrade a 3G is simply what you have just attempted. You download the preferred firmware and Option+Restore button in iTunes.

    If the downgrade process goes alright your iPhone will be downgraded, it springing to life after a successful Restore with 4.0.2 is just not possible :confused:

    Do you get any error messages during the process? Have you tried re-installing iTunes (latest version) or tried this on any other machine than your powerbook g4?
     
  6. celticpride678

    Joined:
    Feb 15, 2009
    Location:
    Boston, MA
    #6
    What makes the 3G different from the 3GS. The iPhone 3G still has signed firmware's and Apple is no longer signing 3.1.3, meaning, unless SHSH blobs are backed up, no matter what device you have, you can't downgrade.

    Don't give false info
     
  7. Zodiak macrumors regular

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    #7
    He doesnt need a previous SHSH file? Even my old Ipod Touch 2g wont let me downgrade to a previous version if I dont have the SHSH file for it. Are you sure?
     
  8. WhatAmI macrumors 6502a

    WhatAmI

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    #8
  9. Applejuiced macrumors Westmere

    Applejuiced

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    Location:
    At the iPhone hacks section.
    #9
    Actually he doesnt need SHSH's to downgrade a 3G to 3.1.3
    They started adding the SHSH check into the ipsw's to 3G iphones from 4.0 or 4.0.1
    So prior to those you can go down to 3.0 or 3.1.2 for example with no probs.
    If you want to go to 4.0 or 4.0.1 it wont let you though. Its a different kind of check unlike the 3GS and iphone 4 on the 3G its just a firmware software check instead of beeing built into the phone.
    SHSH's did not exist for the 3G prior to 4.0 so you dont need them for those builts.
     
  10. TMar macrumors 68000

    TMar

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    Ky
    #10
    Sounds like your forgetting to restore in there? Shift/option click restore and select your ipsw. Short of hardware failure you can't really brick your phone.
     
  11. nora47 macrumors regular

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    Apr 20, 2010
    #11
    is this 100% because im on 4.0 and would love to get back down to 3.1.2 so my phone feels useable again until 4.1 is released which should fix 3g sluggishness.
     
  12. TMar macrumors 68000

    TMar

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    #12
    You might want to check your information before telling others they are giving out false info. The difference between the two is that the challenge/response protocol is hardware based, hardware that the 3g does not have. That's why we didn't have SHSH hashing before the 3gs.
     
  13. WhatAmI macrumors 6502a

    WhatAmI

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    #13
    So latebloomer, keep trying and I still recommend a change of machine.

    *smug grin*
     
  14. Applejuiced macrumors Westmere

    Applejuiced

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    At the iPhone hacks section.
    #14
    Yes it is, give it a try if you dont believe.
    It will go thru restoring to 3.1.3 or 3.1.2
     
  15. latebloomer thread starter macrumors newbie

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    Aug 25, 2010
    #15
    no, i did that step for sure. i wonder whether recboot is doing its job (i.e. actually working) or if firmware 4.0.2 is blocking me from downgrading.
     
  16. TMar macrumors 68000

    TMar

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    #16
    Not sure why your using recboot. Doesn't it just kick it in and out of recovery? You are restoring while in DFU.
     
  17. Zodiak macrumors regular

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    Gatineau, Qc, Canada
    #18
    I'm confused. I have an iPad but I also have an older iPod Touch 2g that I havent used in a while. It is on firmware 3.0 and I wanted to upgrade to firmware 3.1.2 or 3.1.3. I am using itunes 9.2.

    I would connect my iPod Touch 2g to my computer, then put it into DFU Mode (Not in recovery mode) then open itunes. itunes would notice the device in DFU mode and then i would hold Shift and click, then chose the ipod touch 2g 3.1.2 or 3.1.3 firmware. It would then go through the verification process and I always get some error like either 3194 or 3002 which when I did some research, people were pointing to the SHSH file.

    I have tried both with and without having TinyUmbrella active at the same time and with and without the Host file edit.

    If I dont need the SHSH file for 3.1.2 or 3.1.3 does anyone have any help?
     
  18. latebloomer thread starter macrumors newbie

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    Aug 25, 2010
    #19
    1> correct, this is a 3G, NOT a 3Gs
    2> i get error messages twice and they both read "The iPhone "iPhone" could not be restored. An unknown error occurred (1015).

    the first error message appears about 10 minutes after selecting the 3.1.3 restore file that i downloaded.
    that's when i open recboot and select exit recovery mode. a few minutes later i get the same error message. and the connect to itunes logo remains on my iphone.

    3>i have the latest version of itunes.
    4>no, i haven't tried this on any other machine
     
  19. celticpride678

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    Feb 15, 2009
    Location:
    Boston, MA
    #20
    Once it gives you that error message, download RecBoot and kick the device out of recovery mode.
     
  20. latebloomer thread starter macrumors newbie

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    Aug 25, 2010
    #21
    i am following these instructions.
    http://lifehacker.com/5572003/how-to-downgrade-your-iphone-3g[s]-from-ios-4-to-ios-313

    results are similar to theirs right up until the end where it says "Open RecBoot, and click Exit Recovery Mode. In a few seconds, RecBoot should kick you out of plug-me-into-iTunes recovery mode and you'll boot right into your freshly downgraded 3.1.3."

    Recboot never kicks me out of plug-me-into-itunes recovery mode and the "iphone could not be restored error occurred (1015)" message reappears on my desktop.
     
  21. Zodiak macrumors regular

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    Location:
    Gatineau, Qc, Canada
    #22
    Yes i am familiar with RecBoot but the problem is that what i describe above looks for the signature then gives me error 3194 or 3002 but does not restore the firmware file. Thats what im having trouble with because people say that you dont need your SHSH file for firmware 3.1.2 or 3.1.3 but it wont let me.
     
  22. latebloomer thread starter macrumors newbie

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    Aug 25, 2010
    #23

    So, I managed to do it! I looked a little closer and found out that RecBoot was not supported by my Powerbook G4. It doesn't work with PowerPC, only Intel.

    I took it to a friend's MacbookPro, retried everything and it worked the 1st time! My iphone 3G is now running firmware 3.1.3!!!!

    Time to move on to the fun part: jailbreak and unlock!

    Thanks to everyone who contributed to this thread. It was motivational.

    Peace.
     
  23. WhatAmI macrumors 6502a

    WhatAmI

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