Upgrade iOS 4.2.1 on iPhone 3GS (Old Bootrom) with PwnageTool 4.1.3 while Preserving Unlockable Baseband [How-To Guide]

The official PwnageTool bundle to upgrade iOS 4.2.1 on iPhone 3GS (Old bootrom) while preserving its unlockable baseband has been released by iPhone Dev-Team. Follow this guide if you rely on an unlock and want to upgrade your iPhone firmware to iOS 4.2.1 without loosing your unlock.

Note: The following guide will NOT (actually) jailbreak your iPhone 3GS (Old bootrom) but will help you to upgrade your iPhone firmware to iOS 4.2.1 without upgrading its current unlockable baseband. After following the guide below, you still need to use Redsn0w 0.9.6b5 to actually jailbreak your iPhone on iOS 4.2.1. As it is iPhone 3GS with old bootrom, so the jailbreak will be untethered.

iPhone 3GS iOS 4.2.1 PwnageTool Bundle Jailbreak

Steps to Upgrade iOS 4.2.1 on iPhone 3GS (Old Bootrom) with PwnageTool:

  1. Download and install iTunes 10.1 from here
  2. Download PwnageTool 4.1.3 from here
  3. Download iOS 4.2.1 firmware for iPhone 3GS from here
  4. Download iOS 4.2.1 PwnageTool bundle for iPhone3GS from here
  5. Create an empty directory on your desktop and rename it PwnageTool 4.1.3
  6. Place PwnageTool, iOS 4.2.1 IPSW for iPhone 3GS (iPhone2,1_4.2.1_8C148a_Restore) and PwnageTool bundle file (iPhone2,1_4.2.1_8C148a.bundle) in the directory you created in step 5.
  7. Right-click on PwnageTool app, choose Show Package Contents and navigate to Contents/Resources/FirmwareBundles/
  8. iPhone 3GS iOS 4.2.1 PwnageTool Jailbreak

  9. Copy or drag iOS 4.2.1 bundle file (iPhone2,1_4.2.1_8C148a.bundle) in FirmwareBundles directory as shown in the screenshot below:
  10. iPhone 3GS iOS 4.2.1 PwnageTool Jailbreak

  11. Launch PwnageTool, click on the Expert mode, select iPhone 3GS, 3G, 4 from the displayed options and click Next button to continue.
  12. iPhone 3GS iOS 4.2.1 PwnageTool Jailbreak

  13. Click on the browse and select iOS 4.2.1 IPSW for iPhone 3GS (iPhone2,1_4.2.1_8C148a_Restore) that you downloaded in step 3
  14. iPhone 3GS iOS 4.2.1 PwnageTool Jailbreak

  15. Select General tab and click on the Next button.
  16. iPhone 3GS iOS 4.2.1 PwnageTool Jailbreak

  17. Uncheck Activate the phone from the given options and click Next button.
  18. iPhone 3GS iOS 4.2.1 PwnageTool Jailbreak

  19. Click on the Build tab and click on the Next button to continue.
  20. iPhone 3GS iOS 4.2.1 PwnageTool Jailbreak

  21. Now PwnageTool will prompt you to select the directory where you want to save iOS 4.2.1 custom IPSW file for iPhone 3GS. Select Desktop from the drop-down list and click Save button.
  22. iPhone 3GS iOS 4.2.1 PwnageTool Jailbreak

  23. Now wait while PwnageTool build iOS 4.2.1 custom IPSW for your iPhone 3GS.
  24. iPhone 3GS iOS 4.2.1 PwnageTool Jailbreak

  25. Once done, connect your iPhone to your Mac through USB cable and hold down the Power and Home button simultaneously for 10 seconds, after 10 seconds release the Power button but continue holding the Home button until PwnageTool detects your iPhone in DFU mode.
  26. iPhone 3GS iOS 4.2.1 PwnageTool Jailbreak

  27. Thats it! Now you can find iOS 4.2.1 custom IPSW (iPhone2,1_4.2.1_8C148a_Custom_Restore.ipsw) on your desktop.
  28. iPhone 3GS iOS 4.2.1 PwnageTool Jailbreak

Steps to Restore iOS 4.2.1 Custom IPSW Through iTunes:

Select Device from iTunesOnce you have successfully created the iOS 4.2.1 custom IPSW through PwnageTool and your iPhone is in DFU mode, launch iTunes and click on the name of the device from the side panel to view the summary page.
Restore Through iTunes
Now you will see two buttons, Check for Updates and Restore. Hold down the ALT key (SHIFT for Windows) and click on the Restore button to browse for iOS 4.2.1 custom IPSW file you just created with the patched version of PwnageTool 4.1.3

iTunes Restore FirmwareAbove image is for illustration purpose only
Now wait until iTunes restores the custom cooked iOS 4.2.1 IPSW on your iPhone 3GS. If you see iTunes error 1004 or 1015 during the restore, don’t panic because the firmware restore on your device is now complete. All you need is to kick your device out of recovery mode by using RecBoot or TinyUmbrella software.

Recboot - Kick Out of Recovery Mode
Now that you have restored iOS 4.2.1 on your iPhone 3GS without upgrading its baseband, you must follow step-by-step guide here (Skip step 4 & uncheck “Install iPad baseband” option in 8th step) to jailbreak your device with Redsn0w 0.9.6b5. Once done, use this guide to unlock your iPhone 3GS (Old bootrom) with Ultrasn0w 1.2. [via DEV-TEAM BLOG]

Update#1: Fix iPhone 3G/3GS Battery Drainage & Overheating Problems on iOS 4.1/4.2.1
Update#2: How to Activate iPhone 4/3GS/3G without Official SIM with SAM
Update#3: Download official PwnageTool 4.2 for untethered iOS 4.2.1 jailbreak on Mac
Update#4: Download Sn0wbreeze 2.2 for untethered iOS 4.2.1 jailbreak on Windows

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  • armando

    plz i have 3gs iphone but the ios cant be recovery i try this iPhone2_1_4.2.1_8C148a_Restore.ipsw and iPhone2_1_4.2.1_8C148a_Restore.ipsw and i do all this step nothing happen it stell the same stop @ itune logo plz help me plz

    • Wolverine

      Do you rely on an unlocked iPhone? If yes then what is your baseband?

  • Jamaal

    ok,i have an iphone 3gs 4.2.1fw baseband 5.15.4 I jailbroke it with redsnow but to unlock ultrasnow 1.2 won’t work because I havt to upgrade to 6.15.00,now what I need to know is from here how do upgrade properly and unlock my phone to use it with t mobile..step by step plz I want to get this correct the fist time..thank you..

  • matt

    i did all the tuto as it is written but my iphone stucked during the resauration
    around 90% of it
    what do i have to do?

  • iTarek


    thanks for ur instructions, i do what u say now i have locked iphone 3gs ios 4.2.1 baseband 05.11.07, but when i use ultrasnow to unlock my iphone not working give me searching then no services.
    can u help me please

    if u don`t have objection add me on msn id: tarek852@msn.com


  • misterterry

    If I understand correctly, jailbreaking is not necessary after restoring the custom 4.2.1, right? That is, if on official SIM with no need to unlock and no need to install cydia, I can just use your guide to create and install custom IPSW in order to simply preserve old baseband?

    If so, can these same steps be used on 3gs NEW bootrom if no jailbreak is intended? Is jailbreak necessary step on NEW bootrom?

  • Nirujan

    Will this work on iphone 3g? and in the last step about using recboot, should i open recboot before i start the restore process or when i get the error?

  • Bobby

    Hi wolverine what u hav said in above process make a video any post it on YouTube plz so that I can understand clearly, if u already done plz give me the link to my mailed plz plz…

  • Fredrick Tetteh

    Will untethered jailbreak kick me out of connect to itunes screen on the ios 4.2.1? and will there be a new pwnage tool to support 3gs 4.2.1?

  • gee

    oh i believe my IPSW was corrupted. i will try it again.

  • gee


    I did exactly as you said (and have 3gs with old bootrom) but for whatever reason PwnageTool gives me a “wrong firmware” error. I did use 4.2.1 ipsw and also correctly copied the bundle, and i am certain that i am on a 4.xx.xx bootrom with a 3GS. whats the problem?

    Also, a friend of mine has a 4.1 with a NEW bootrom. it is not possible to still downgrade the bootrom to a 3.x version, is it? because that would make things easier, i guess. we do have the SHSH things on cydia.

  • Fredrick Tetteh

    My curent firmware version is 4.2.1

    • Wolverine

      I am sorry but you will not be able to downgrade iOS 4.2.1 to iOS 4.1 without SHSH blobs. Hopefully, you will get an untethered iOS 4.2.1 jailbreak on iPhone 3GS before Christmas.

  • Fredrick Tetteh

    Can i use pwnage tool 4.1.3 to create iphone 3gs ios 4.1 custom ipsw because i havent saved my shsh and will itunes accept the custom ipsw since apple has stopped signing ios 4.1

  • virginsky

    I have 3GS with old baseband but I was unable to restore the phone…. it got stuck at apple logo and all effort to restore failed … given error 3194 and cant upgrade nor downgrade… pls help

    • Wolverine

      Error 3194 means your SHSH blobs are not saved properly. Can you please tell me your current firmware and baseband version?

      • virginsky

        the last firmware was 4.0 and 05.13.04 …. and I erased all the content of the phone with the intension of restoring it to 4.1 and preserve the baseband. Pls assist

        • Wolverine

          You got error 3194 while restoring iOS 4.1 custom IPSW when your iPhone was on iOS 4.0? If that’s the case, its impossible because you never need SHSH blobs while upgrading to a higher firmware version.

          • virginsky

            its like apple cannot verify os 4.1 anymore

  • Fredrick Tetteh

    What if i didnt save my SHSH blobs for 4.1?wat can i do then cos am still stuck at the connect to itunes screen.pls help

    • Wolverine

      If you have saved iOS 4.1 SHSH blobs, you can downgrade your iPhone 3GS from iOS 4.2.1 to iOS 4.1 by restoring iOS 4.1 custom IPSW for iPhone 3GS.

  • nacho

    Why this will not work with 3G? :(
    There is any way to do it with 3G?

  • Ketil

    Would this work even for a 3G?


  • fredrick tetteh

    i have 3gs ios 4.2.1 new bootrom bb 6.15.00 and stuck to connect to itunes screen..what should i do?will itunes allow me to restore to 4.1 since it verifies with server before allowing restore

    • Wolverine

      Provided that you have saved iOS 4.1 SHSH blobs, you can find the downgrade guide here in the answer!

  • Pete S

    Hi- Thanks for tutorial- 3gs old boot now 3.1.2 5.11.07- On the redsn0w part do you point to the stock 4.2.1 or the custom one made with the pwnage tool? Thanks!

    • Wolverine

      Use stock iOS 4.2.1 IPSW but skip step 4 and don’t forget to UNCHECK Install iPad baseband option (8th Step) in Redsn0w tutorial here.

      • Sebastian

        are you sure? is in contradiction with step 5 from that tutorial ! i am a little confused right now. :(

        • Wolverine

          Once you will use the above tutorial, it will upgrade your iPhone 3GS to iOS 4.2.1 with baseband 5.11.07. You need to skip step 4 because if you will restore iOS 4.2.1 stock IPSW on your iPhone, it will upgrade its baseband to 05.15.04. So skip the step 4 as you have already restored iOS 4.2.1 (Custom IPSW) but without upgrading your baseband. You need to provide stock iOS 4.2.1 on step 5, it will not upgrade your baseband but will just used to patch your file system!

  • Calio

    These instructions seems to be for the 3gs old bootrom only. Can you create custom 4.2.1 ipsw for the new bootrom 3gs and update the same way? My baseband is 05.11.07 and i rely on my unlock to use the phone with my carrier. currently on 3.1.2 jailbroken and unlocked with ultrasnow. i am a mac user so will PwnageTool be able to create the custom 3gs ipsw i need to update? if not this way what is the best way to update 3gs new bootrom? I have all my blobs saved from 4.0.1 and up. Any advice would be welcome. Cheers

    • Wolverine

      I would advise you not to upgrade to iOS 4.2.1 even if you get PwnageTool bundle for iOS 4.2.1 iPhone 3GS (New Bootrom) because it will be a tethered jailbreak. Moreover you might loose your unlock if PwnageTool bundle failed to preserve your baseband. Currently there is no tool to jailbreak iOS 4.2.1 on iPhone 3GS (New Bootrom) untethered. So its better to wait for Comex hacks which will enable you to have untethered jailbreak on your device but thats only possible if you have SHSH blobs saved for the previous firmwares.

  • Tee

    What about us without a MAC? Can you upload the custom firmware?

  • drifterk

    Hi wolverine … thanks for the steps provided but i have a question … I have 3GS with old bootrom currently on 4.0 and baseband 05.13.04. Using your steps above i should have 4.2.1 on my 3GS with my 05.13.04 baseband ( which is unlockable by Ultrasn0w). Towards the end u say we have to use redsn0w to jailbreak but the instructions there refer to upgrading baseband to 06.15.00 . Please clarify ?

    • Wolverine

      Yep, you must skip the upgrade to iPad baseband part in that tutorial. Just check Cydia and point it on iOS 4.2.1 baseband.

  • Yardus

    i can enter to the phone later PwnageTool because i have a old AT&T sim car, the phone have cydia, but this don’t work. And try use Redsn0w an this make error installing cydia again. Please help.

    P.D. The phone have the old boot with 4.2.1.

    Thanks, Yardus.

  • Yardus

    The 3gs have a 4.2.1 install with old boot, cydia is install but donk work.

    • Wolverine

      You have to re-jailbreak your iPhone with Redsn0w again to update your Cydia.

  • Yardus

    Everything is fine until the point of creating the custom firware, but the passage of
    using redsn0w tutorial says to “install iPad modem”, do not you this raises the baseband? that is precisely what we want to avoid!

    Thanks, Yardus (3GS old Boot)

    • Wolverine

      Oh yes! Don’t select that option! Forgot to mention

      • Yardus

        All is well until redsn0w point, when I go to redsn0w, I follow the steps and give it to install cydia and then get a white screen and does nothing.


  • sam

    I have Iphone 3GS 4.2.1 with 6.15.00 stucked at restore. Its only showing a apple logo and failed official restore bcoz of ipad baseband on it.
    i have windows OS so cant use the latest Pwnage tool to make custom ipsw file for iphone 3gs 4.2.1 with new boot rom.



    • Wolverine

      Restore to iOS 4.1 now, else you won’t be able to kick your device out of recovery mode due to baseband protection.

  • Nelfco

    I’m cooking right now the custom 4.2.1 for my 3gs old bootrom hope everything goes well. I think redsn0w doesn’t support hacktivation try to get any at&t simcard to get it activated

    • Wolverine

      It supports hacktivation! No need to worry about that =)

  • portowine

    I made the process with the PwnageTool.
    But now when I reboot the iphone it appears the itunes activation and when I try to use the Redsn0w 0.9.6b5, this one crashes.
    Please help me to solve this.

    • portowine

      I forgot to say that tinyumbrella says that the iphone has IOS4.2.1 and baseband: 05.13.04-6.4_M3S2


      • Wolverine

        Redsn0w is crashing? You are using Windows or Mac version of Redsn0w?

        • portowine

          Mac version.
          I also tried on windows xp (Parallels and before install limera1 the iphone restart)

          • Wolverine

            What? You used Limera1n to put your iPhone in DFU mode? Limera1n will never jailbreak iOS 4.2.1.

        • nicholas

          does this ork on windows?

          • Wolverine

            No, its only for Mac at the moment. Wait for Sn0wbreeze