How to jailbreak and unlock iPhone 3GS firmware by downgrading it from 3.1.3 to 3.1.2

A lot of users upgraded their iPhone 3GS firmware from 3.1.2 to 3.1.3 without knowing the consequences. So, if you want to jailbreak and unlock it using blackra1n, you’ll have to downgrade to 3.1.2 but the modem firmware will still be 05.12.01. Remember, before trying this out, back up your data. If you end up bricking your iPhone, I won’t be responsible for it. ( Credit for this guide goes to Cliff who sent it in! )

  1. Uninstall iTunes 9.0.3 to from your computer. Remember to back up your data, and rename the iTunes library folder to something else.
  2. Download and install iTunes 8.2.1. Download 3.1.2 firmware to your computer. ( links at the end of this post ).
  3. Connect your phone to the computer and hold shift and click restore in iTunes. Select the 3.1.2 firmware file.
  4. The restore might get stuck and you’ll get an error 1015 message.
  5. Ignore it and reboot your iPhone using the power + home buttons.
  6. You’ll now see the USB and iTunes logo on the iPhone display. This means that firmware 3.1.2 is installed. But right now, the phone is stuck in a DFU loop.
  7. To fix this, you’ll need to use iRecovery.
  8. Once you’re out of the DFU loop, iTunes will ask you to sync with the old backup. We suggest you avoid that and opt to set up a new phone. iTunes will reactivate your iPhone.
  9. Follow our guide on how to jailbreak iPhone 3GS with OS 3.1.2 with blackra1n RC3.
  10. You can now unlock your iPhone using blackra1n RC3. Follow this guide for instructions.

If you are running into issues, follow this guide to jailbreak and unlock your iPhone 3GS.

If you are using iPhone 2G, 3G, iPod Touch 1G or 2G ( non-MC models) follow this guide to jailbreak OS 3.1.3 with redsn0w.

Download iTunes 8.2.1 (32 bit)

Download iTunes 8.2.1 (64 bit)

Download iPhone 3GS OS 3.1.2

Update: Use this guide to jailbreak iPhone 3G/3GS with OS 3.1.3/3.1.2 untethered! ( no unlock yet, though)

Note: This method doesn’t work anymore. follow this guide to jailbreak and unlock your iPhone 3GS.

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92 comments

  1. Looks like if your 3GS is new out of the box, it can be downgraded to 3.1.2 BUT cannot be jailbroken. Unless you have a 3GS that was previously jailbroken you wont be able to jailbreak the 3.1.3 version even if you manage to get it downgraded to 3.1.2

    That seems to be the consensus thus far. Also GeoHot reckons it wont happen http://www.iphonedownloadblog.com/tag/jailbreak/

  2. my 3gs was JB until i updated it to 3.1.3 when the “great” update came out. now i’m stuck with it, i’ve tried a couple different ways today and 3.1.3 is still trapped on my phone. if anyone has tips or suggestions plz help me.

  3. my iphone 3gs was JB’ed , but unfortunately I upgraded to 3.1.3 , I am also stuck at the same point “This device isn’t eligible for the requested build”

  4. Rock screwed my 3GS, it changed my ssh password? while on 3,1,2 then while I was busy sorting it, it rebooted got stuck at Apple logo, so tried to restore but itunes wouldn’t let me go back to 3,1,2 so I’m on 3,1,3 and to top it off my itunes account has been disabled???
    Apple b@stards.

  5. On a later model 3GS (one that only has a “tethered jailbreak”) I too am getting the ‘not eligible’ error despite following these instructions.

    It’s odd, makes one wonder if going back to an even older version of iTunes would help?

    Fortunately my phone is still jailbroken and unlocked at this point but it definitely majorly suxxors to not be able to restore to 3.1.2 (I’ve not got a 3.1.2 SHSH file saved unfortunately).

    -3.1.2 Restore Incapable iPhone Owner

  6. Please help! I got the same error message “could not be restored. The device is not eligible for the requested build.

  7. i have the same prob with my 3gs …i called many people to help me resolve this prob but they all told me that it’s not possible yet….so i met a guy in downtown who told me i can do it …i gave it to him and he told me it will be ready tomorrow morning….hope he will success…if yes i will give you his phone adress…THKS

  8. no its not working
    i uninstall the new version and i install the old version iTunes it not supporting

  9. IT’s no longer eligible for the build because Apple stopped signing the release yesterday. Sorry guys, THIS, no longer works. Apple is no longer signing 3.1.2

  10. When holding Shift, I don’t get the option to restore it to firmware 3.1.2 even though I’v downloaded it onto my computer.
    How does this box come up?
    I’m on a PC running Windows Vista
    & have an Iphone 3GS

    Please advise for the people who it worked for.

  11. What bothers me the most is all the money I spent on Rock and Sydia! I wonder if and when I’m able to JB with BR if I can get all that back???

  12. Downgrade iPhone 3GS OS 3.1.3 to 3.1.2 I receive an error message like (The iPhone could not br restore. This device isn’t eligible for requested build.) I need Help
    Thanks,

  13. Downgrade work for me.
    Follow the process above and delete all files related to itune 9.0.3 and install itunes 8.0.3. That’s all

    1. you mean to say you have 3.1.3 version and baseband 05.12.01, and you manage to downgrade it to 3.1.2 version and you jailbreak and unlock your iphone 3gs, just following the process above tell me its right!!!let me know

  14. This does not work at all. If anyone wants to JB their iPhone, I suggest waiting for Geohot to come up with something. It might take awhile, I guess we all have to have patience. My phone never got a 1015 message, all it says is that build is not eligible. I give up. I guess I have to wait like everyone elst. My jb 3gs is not jb anymore.

  15. As it says all the way on the top: “Note: This method doesn’t work anymore.”

    People like me with 3GS and baseband 05.12.01 will indeed have to wait for something to come up that will work. For now, there’s no option but to wait…unfortunately.

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