Unlock iPhone

How To Downgrade iPhone 3.1 Baseband From 05.11.07 to 04.26.08

September 24, 2009 — by Simon Ng49


Unlock iPhone

How To Downgrade iPhone 3.1 Baseband From 05.11.07 to 04.26.08

September 24, 2009 — by Simon Ng49

Download BasebandThough it’s warned by the iPhone Dev Team not to upgrade your iPhone OS directly via iTunes. I’ve got quite a number of emails from iPhone jailbreakers telling that:

Oh! I accidentally upgraded my iPhone 3G to firmware 3.1 by iTunes. After upgrade, I lost the jailbreak and the unlock. Now, I can’t make call with my iPhone. Even I jailbreak it again, it still doesn’t work and with no service. Any solution?

Probably you’re facing the same problem. As you may not know, the iPhone OS 3.1 also comes with a baseband update to 05.11.07 for iPhone 3G. However, the Ultrasn0w (i.e. the iPhone unlock tool) cannot unlock this version of baseband. It can only handle the lower baseband version 04.26.08. That is the reason why we emphasize not to upgrade to iPhone 3.1 via iTunes directly, particular you need to use ultrasn0w for unlocking.

Fortunately, there is a solution for that, though not for all iPhones. Thanks for the developers of Fuzzyband Downgrader. Fuzzyband is a tool that allows you to downgrade the baseband from 05.11.07 to 04.28.06. By downgrading the baseband, you can use ultrasn0w to unlock your iPhone again.

Cool, right? There is a catch, however. Fuzzyband can only support iPhone with bootloader 05.08 (5.8) from the factory. Only a limited number of iPhones that were released in the first few weeks of the iPhone 3G production cycle were loaded with the bootloader version. For other bootloader versions, I regret that you need to wait for iPhone Dev team to release the unlock solution. Not sure your bootloader version? Fuzzyband will take care that for you and verify if your iPhone is using the valid bootloader version.

Okay, here we go. Note that this guide is for iPhone 3G ONLY.

Downgrade Baseband from 05.11.07 to 04.26.08

1. First, you need to jailbreak your iPhone. If you’re using Mac, follow the step-by-step jailbreak guide for iPhone 3.1 to jailbreak your iPhone. For Windows users, you can restore back to iPhone 3.0 OS first, followed with jailbreak using redsn0w. You can follow this downgrade guide for details.

2. Once jailbroken, launch Cydia and search for “Fuzzyband”. Then install the application.

Search Fuzzyband in CydiaInstall Fuzzyband

3. After installation, go back to home screen and tap “Fuzzyband” to launch it.

4. Tap the “Downgrade” button to kick off the baseband downgrade.

Fuzzyband Downgrade for iPhone 3.1 Baseband

Once you complete the baseband downgrade to 04.26.08 successfully, you can download ultrasn0w to unlock your iPhone. For instructions, you can follow the step by step unlock guide using ultrasn0w.

Let me know if this solution works for you. I hope Fuzzyband can help some of you to recover your iPhone, for which was accidentally upgraded to iPhone OS 3.1.

Simon Ng

Founder, developer and chief blogger of simonblog.com

  • mikey

    accidently upgraded to 3.1 now wanted to downgrade it to 3.0 but getting an error 1015 towards the end (about 70%) of restoring the firmware 3.0 . I tried it with itune 8.2 and again with itune 9. same result so I restored back to 3.1 now waiting …….. for news

    • vu

      use quickpwn 221 restone

  • Thanks for the iPhone information that you’ve shared in this post.

  • UrbanZ

    When you have the error 1015 close the itunes and open the QUICKPWN –> http://www.megaupload.com/?d=H4BLU49J (download link), and follow the instruction that appears in message (Power button + Home button (15s), Release the home button and wait 2s power button) you will see the apple logo
    (this is for windows)

    But if you have the baseband 05.11.07 this don’t downgrade the baseband to 4.6!

    Sorry my english, i’m portuguese

  • hi, the fuzzyband solution is only for iphone with bootloader 5.8. i had one but my bootloader is 5.9. could u help me how can i unlock my iphone please…

    • UrbanZ

      I have the same problem, i can downgrade my baseband 05.11.07 because my bootloader is 5.9. =/

      • @Urbanz, there is no way to downgrade baseband for bootloader 5.9 for now. Please be patient and wait for iPhone Dev team to release an unlock solution.

      • mikey

        Thanxs buddy for helping me out with ‘the 1015 error’ solution now I m wainting for the unlock just like u guys…….. let me know when the unlock solution comes up. Cheers

  • Liang Zhou

    OMG!!! I am having the same problem, but because my bootloader is 5.9…on 3G firmwire 3.0… this is scary because I do not understand why Apple have to release such phone out when they do not have the full responsibility on the phone…this is really crazy. How can you buy the phone and still not be able to use it due to crazy updates you do….I’m really pissed OFF…


    • Carla

      yeah, that really sucks!

  • I was woundering if I can downgrade my firmware? Because my bootloader version is 06.04 and is there some way to to it right now? And fuzzyband says “NOT SUPPORTED” for that. it says only working for bootloader 05.08

    ???? HELP ????

  • UrbanZ

    Yes you can downgrade your firmware, but you can’t downgrade baseband, you need bootloader v. 5.8 to do this process =S

    I still waiting for solution =/

  • Okey I See..

    So if I want to unlock my phone I need to wait til bootloader v 5.8 comes out?

    Do you know how long this going to take before it release?

  • UrbanZ

    this process only work with old bootloader (5.8), don’t have a solution to bootloader higher than 5.8. Only wait for new release of fuzzyband or dev team with new ultrasn0w. =S

  • Crowsoul

    Would that unlock my 3GS that came out of the box with 3.1.2 and a 05.11.07 baseband?

    • @Crowsoul, it’s very likely the latest batch of iPhone 3GS comes with baseband 05.11.07.

  • amin

    I install that but when open it show not supported.
    ” this software cannot be used on iphone os 3.0 ; you must downgrade to 2.2.1 or lower.”
    If I downgrade can I change my basebond? from 5.11.7 to lower!
    because I dont have antena!!!

    • Sam

      Baseband 5.11.7 can be downgraded using Fuzzyband tool only if bootloader version is 5.8 or below of your Iphone, if it is 5.9, fuzzyband can not downgrade baseband of your iPhone. You have to find another way, I am also looking for one. Please let me know too if you find one. Thanks!

  • UrbanZ

    Download fuzzyband, not the “3g fuzzyband downgrade”

    Good luck

  • amin

    So thanks sir
    I do that but my bootloader is 5.9
    Can I change my boot loader?

  • UrbanZ#

    Sorry, but you can change bootloader the difference between 5.8 and 5.9 is not only software, have hardware to.
    I’m in the same situation, wait for dev team solution 🙁

  • UrbanZ#

    Good news guys and girls, geohot is working in a solution to unlock baseband 05.11

    All info here http://www.funkyspacemonkey.com/geohot-baseband-0511-unlocked-moment

  • Amin

    this site don’t open. It has some problem!

  • Paramveer Bhatia

    I have iphone 3gs on that i have 3.1.2 firmware with a baseband 05.11.07 now i am able to unlock my iphone so i need help plz tell me if any baseband downgrade option or unlock option for iphone 3gs…….thnx in advance

  • Paramveer Bhatia

    I have iphone 3gs on that i have 3.1.2 firmware with a baseband 05.11.07 now i am not able to unlock my iphone so i need help plz tell me if any baseband downgrade option or unlock option for iphone 3gs…….thnx in advance

    • @Paramveer, for the time being, there is no solution to unlock that version of baseband.

  • UrbanZ

    Exactly for now no solution, but geohot and the rest of the team is working to find a new exploit to unlock this baseband.

  • krasimir

    Hi Simon,
    I read everything, but still i’ll ask what i can do with iphone 3G 3.0 (i don’t know the history of this phone) after i restore it and giving me error 1015, then i actived and jailbreak it with redsn0w 8, i try fuzzyband downgrader but i get message “not supported” :Bootloader Version 05.09 and baseband version 05.11.07
    so do i have to wait for new software or there is some solution

  • stephanie

    its telling me downgrading will only work with baseband bootloader 05.08??? please help being trying to unlock this thing for months!!! arghhhh!!!!

  • UrbanZ#

    Wait, Geohot is working in unlock for bb 05.11.07

    see this –> http://www.iphonedownloadblog.com/2009/10/28/geohot-unlock-iphone-baseband-05-11-07/

  • iphoneR


    Geohot is releasing an unlock for iPhone Baseband Version 05.11.07 on 3/11/2009.
    Does this mean if I have Bootloader Version 5.9 with 05.11.07 I will be able to downgrade my boot loader to version 4.6 if I wanted to change the IMEI?

  • UrbanZ#

    Wrong information, geohot release blacksn0w on 04-11-09.

    You be able to change imei in iPhone classic.

  • iphoneR

    Hi UrbanZ#,

    Change the IMEI in iPhone classic?
    Can you explain?

  • UrbanZ#
  • iphoneR


    That shows how to IMEI change with BL 4.6
    iPhone’s updated with 3.1.2 would have a later version than BL 4.6, right?

  • iphoneR

    Upgrading the iPhone firmware to version 3.1.2, updates the Bootloader to version 5.9

    Is it possible to downgrade the Bootloader from version 5.9 to version 4.6 and using ziphone to change the IMEI?

    • @iPhoneR, no need to downgrade the baseband. GeoHot will release the unlock solution to unlock iPhone 3.1.2. The application is called blacksn0w. I’ll soon post an update about that.

  • Carla

    oops! sorry i followed the comments & found out that fuzzyband downgrader is only capable of downgrading 5.8 baseband to 4.26.08, thanks again. Im sad about this news.

  • iphoneR

    @Simon NG – I have to downgrade the BOOTLOADER from version 5.9/6.2 (whatever firmware 3.1.2 upgrades it too) to BOOTLOADER version 4.6 (as shown: http://www.iclarified.com/entry/index.php?enid=657) so I’m able to change the IMEI.

  • Imzee

    hi mine says my bootloader version is 06.04 and wont let me downgrade is there any way to fix this please

    thank you

  • Okey. I have the same problem like you Imzee before… IF you want to UNLOCK it. Just download blacksn0w and install it on your iphone, then your are good to go!

    Good look

    ps. http://techpp.com/2009/11/03/unlock-iphone-3-1-2-firmware-with-blacksn0w/

    There your go if you WANT TO UNLOCK Iphone that have 3.1.2 Firmware (doesent really matter what bootloader your have) peace

    • Aaron

      All, i have a iphone 3g and downgrade from 3.1 to 3.0. My bootloader is 6.4. Has anybody successfully unlock the phone yet?

      • @Aaron,

        GeoHot has released a new jailbreak and unlock tool to handle the latest version of baseband. You do not need to tackle with the downgrade anymore. Just check out this jailbreak guide and unlock your iPhone with blacksn0w.

  • Tomer

    Note that this is also a great tool for upgrading your baseband to a desired firmware (assuming you used a custom firmware thus preserving an old FW (2.28.00, for example) that doesn’t work with ultrasn0w)

    helped me a lot

  • Sadboy

    Hello Simon. I am the lucky guy who didn’t update his phone via iTunes this time. I am having 3.0 in my iPhone. Can you please help me how to get bitesms application in my iPhone. Previously it was free but now they are charging. Problem is that don’t have credit card here in Pakistan, so please help me how to get bitesms. I’ll be very thankfull to you. Regards

    • @Sadboy, do you have a Paypal account? You can make the payment via Paypal. Otherwise, you need to have a credit card for the payment.

  • my bootloader 6.4 Lolz

  • HB

    I have a new iphone 3g Which i had unlocked using redsn0w

    Firmware 3.1.3
    baseband 05.12.01
    bootloader 06.04 .

    Can anyone tell how to unlock this phone?

  • luc1f3r

    hey guys ive got a 3.1.3 bl 6.4 needing to change the imie as its been reported lost by the previous owner and yes it was lost 😀 i know cause i found it…. anywys im askin anyone that doesnt mind helpin someone thats not exactly honest… i refuse to give it back for one reason alone.. its worth a heap and well.. I FKN FOUND IT :/! aaanyways.. if anyone knnows hot to either downgrade the BL or change the imie without to much hassle or hardware variations pls email me at [email protected]