iPhone Dev Team Working On A Solution To Downgrade Baseband 06.15.00 To 05.15.05 For iPhone 3GS, iPhone 3G

Jailbreak iOS 4.1 for iPhone 3G - Redsn0w

Some users have reported significant loss of GPS signal after upgrading to baseband 06.15.00 using Redsn0w or PwnageTool to unlock their iPhone.

MuscleNerd of the iPhone Dev Team has just confirmed that they are working on a solution that will allow users to downgrade their iPhone’s baseband back to 05.15.04.

MuscleNerd revealed this while responding to one of his followers on Twitter:

@Lezanz sorry still collecting data on that. But also working on a bb downgrade (!) method for those with unlockable bb

@idansc yes if the BB downgrade method works, it will work for 06.15 too.

We are assuming that the iPhone will still be unlocked after downgrading to baseband 05.15.04.

MuscleNerd of the iPhone Dev Team also revealed earlier today that he has managed to get untethered jailbreak to work on iOS 4.2.1. But MuscleNerd hasn’t provided an ETA on when the updated tools will be released. We’ll let you know if there are any further updates.

Are you are experiencing any issues with GPS on your iPhone after unlocking it using the combination of PwnageTool or Redsn0w and Ultrasn0w? Do you want to downgrade the baseband from 06.15.00 to 05.15.04? Please let us know in the comments below.

[via MuscleNerd]

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  • Sid

    Good News.. Cheers guys!

  • Ciprian Biris

    So.. i will be able to unlock stock iOs 4.1 on my iphone 4?

  • Lee

    Downgrade to 5.15? And can we still unblock it?
    How about the 2.10 for iPhone 4 pls any progress ?

    • Dev Team hasn’t provided any update on the unlock for iPhone 4 baseband other than saying it will need more efforts. We will keep you posted if we have any news on that front.

      • OneTriniHill

        I’m trying to unlock my iPhone 3GS (old bootrom) and it keeps going into dfu mode. I’ve tried redsn0w and I’ve tried booting it *tethered* but it still won’t boot and stays in recovery mode. I’ve been trying to use the pwngetool also but it does not give me the option to fetch the iPad 3.2.2 firmware so I can unlock. IDK what the problem is and it won’t even let me restore to an official firmware bundle (it’s running iOS 4.2.1/4.2). What can I do. I’ve been up all night pulling my hair out here!

        • ok mk

          I’m assuming that you have the proper ipsw downloaded for your iPhone? Maybe double check first.

          When I did it to my 3GS i actually did it in different steps using redsn0w 2 separate times. Try to Flash the iPad BB first, then install Cydia separately.

          If you’re using pwnage tool, make sure that you downloaded the newest version. They released a special Unlock Edition just for the 6.15 BB unlock, but you must also download the iPad 3.2.2 FW ipsw if you are using Pwnage tool.

          Hope that helps.

          • Scott

            Try to dl a custom firmware open iTunes hit restore while holding shift key and look for the custom firmware you dl’d

        • DiabloZoe

          try Ireb!

        • cshankar

          its possible that your iphone baseband upgraded to 6.15 but since you are restoring to 4.2.1 itunes will not let it restore.

          I suggest that you try downgrading to 4.1 ipsw and then use iRecovery or iReb to kick out of recovery. If it works, then pl do not upgrade to 4.2.1.

          I had the same problem and downgrading to 4.1 ipsw and using iReb solved my issue. Took me 2 days to figure this out though.

          • Dizzy

            tinyumbrella? have you tried that – it has options for kicking out of recovery (itunes 10xx errors). It’s a good idea to save your shsh (blobs) files while you’re in there too. Check with tinyumbrella which versions of IOS are being signed by Apple (or cydia server via tinyumbrella) for your phone. You should be fine with 4.1 anyway. Get to know this program if you’re jailbreaking it will really help you. Another idea, to expand on custom firmware, use sn0wbreeze and build your own. SBreeze will put your phone in ‘pwned DFU’ mode so iTunes will accept the custom firmware it builds too. You need to get the correct version of SBreeze for the firmware version you want to build a custom for. You may know some of this and you’ve probably fixed it by now! lol – hope it might give some hints to others if not.

  • monkey_duster

    I hope it will be applicable to an iPhone 4 with a 2.10.04 BB. thank you dev team for all the efforts!

  • davidj

    thanks so much DEV…for the new 3gs comers, after the new solution come out, can we jailbreak and unlock the 3GS with IOS 4.1 and BB 5.14.02 with this new solution without upgrading the new BB and downgrade back to 5.15.xx?

  • glynnmac

    Looking forward to this. I miss my GPS. Great work!

  • GoPadge

    I’m having trouble with Facebook. My wife keeps getting Facebook notifications if foreign languages. (German, Japanese, Russian, and Spanish so far.)

    • Matthew Etchells

      i too get problems with facebook and twitter notifications, for some reason i keep seeing that its always addressed to a AZSPORTSFAN, i want my baseband downgraded.

  • volsk

    Yes please! Downgrade would be of great help. Even it is not possible to unlock.

    • Dizzy

      I agree with that – I’ve been waiting on BB downgrade – I’m one of the unlucky ones with a 3GS with carrier problems after JB. I’m really looking forward to BB downgradge in the hope I can start a fresh with my phone. Proper respect to Dev team for working on this. Can you imagine (I can’t) how many development hours these guys have put in on JBreaks.

  • this guy

    why i cant update to 4.2.1 after i JB and flash the bb 6.15 on my 3g? help!!

    • u cant do a update after using 6 15

  • gee

    Sounds good but I’m not having any issues right now with GPS. Currently have 3GS OS 4.1, BB 6.15 unlocked on T-Mobile and all is good. Would probably look at downgrading only if there were an issue. I had my original SIM card from ATT from a while ago and that activated it so I’m not having any GPS or battery issues.

    • HEY

      Gee, how did you do it? I am scared of upgrade to 6.15 and have multiple problems. I have 3gs, 4.1, 5.14.02. Its JB with snowbreeze already have cydia.Was using ATT now Im trying to get T-mobile.
      thanks in advance…

      • gee

        I just followed the instructions and believe me, I’m new to this whole thing. I downloaded the 4.1 and 4.2 and ipad ipsw’s like they said and then I ran redsn0w. When prompted I pointed to the 4.1 ipsw because I wanted to keep my untethered jailbreak if possible and it went through just fine. Then loaded the ultrasn0w unlock and it was ready to go. I used my old ATT SIM to activate it and then I put the T-Mobile SIM in and it works fine. GPS and battery are not an issue as I believe it’s only an issue with 4.2 and anyone who didn’t activate with SIM card. Like I said, I’m new to this and I did it so follow the directions and you should be fine. Make sure to use the utilities to backup your phone just in case.

        • HEY

          Gee, Im sorry but I am already on 4.1. Should i proceed with the IPSW ipad download then run redsn0w?

          • gee

            I was also on (and still am) on 4.1 but you need to download that as well as the iPad ipsw. Part of running the redsn0w it will ask you for your ipsw of the OS YOU ARE ON NOW and that’s where you need to point to the 4.1 ipsw. then a little later during the install it will ask you where the iPad ipsw is so you need both before you move forward. I think that first step is the important one to stay on 4.1 and have the untethered jailbreak. if you (or anyone else) accidentally points to the 4.2 ipsw you’ll end up on 4.2 where you don’t want to be. Just make sure you have both the 4.1 and ipad ipsw and you should be all set.

        • HEY

          Thanks man, I will let you know how’d it go. Hopefully it works for me.

  • locone

    Thanks DEV team, you’re the BEST of the BEST.

  • sdguy

    I still have GPS after unlocking my 3GS (old bootrom) on bb06.15 buy it is usually 2 to 3 miles off. If the downgrade keeps my phone unlocked, would love to downgrade. Otherwise, love a fix to the GPS issue. Good luck guys. You always do great work.

  • munaf

    i dont understand one thing if the dev team have not retested their new baseband then why they release i meam why the fuck they are creating a big scene that they got a solution for iphone unlock.dev team first find the right unlock thats 5.15.01 and then do party

  • Ray


    EMAIL ME @ poppin3000@yahoo.com for intructions

    • Michael

      Ray you are a liar. Nobody listen to him, he is going to scam you.

      • Jasonjason

        Lol ^^^

        I wouldn’t mind downgrading but if there’s an easy fix for gps my battery is fine

  • YO

    Hello Guys,

    I am having a problem here with my Iphone 3gs on IOS 4.1 and FW 5.14.02. serial # indicate that i have a old bootrom, but when i ran redsn0w during the process it prompted and said that i have a new one even though i had selected that i have a old one by checking the serial # in my device. 4th # is a 3 follow by a 1.

  • fas

    Why is there so much attention to the 3G and 3GS? Why dont they bother about the 4?

    • davidj

      fas…people have 3g/3gs before the 4 comes out…lol

  • mike

    i just onluck my iphone 3g fw 5.14.02 using redsn0w upgrading baseband to 6.15
    and them ultrasn0w for now i don’t see any gps problems is perfect i have simplemobile carrier. phone is working perfect for me and plus i fixed my mms problem but i wish if we can downgrade the baseband 6.15 to 5.15. 0n the feature is going to be much better

  • tempdomain

    Shouldn’t the title be 05.15.04 instead of 05.15.05?

  • Y Some iphones r working perfectly and some with issues..Any body knows dat Y I m having GPS issue(not battery, its working same good), only GPS problem and many of my buddies facing both of them OR like above buddy *mike’s working fine*,,,,So WAT IS THE DIFFERENCE BETWN MY IPHONE 3GS (5.14.02->6.15 = 4.1) AND OTHER ONES….IS IT THE SERIAL UIDI OR SOMETHING LIKE THAT NUMBER, WHICH INDICATES SPECIFIC PROBLEM OR THE SOFTWARE Redsnow or Pwnage, which creates problem in our device……Y WITH SOME AND NOT WITH ALL……Y ALL DIS FUCK HAPPEN…CAN ANYBODY TELL ME….iPhoneHacks plz tell us,,,,Y,,,,,V changed our window, Pc to Mac, Updated Driver and all Fine,,,But Y v r facing those issues,,,(“)

  • k10

    Unlock solution for iOS 4.1 baseband 05.14.02 please?

    • gee

      redsn0w and ultrasn0w. Works fine.

  • Iphone4life

    Gps is a problem …… Go0gle seem be little of but kinda working how 2 test take wi-fi off and location On also noticed when wifi on google maps more exact? dev team great work so far keep up the good job/work yyyyyyyyyyy v r apple and not gingerbread yyyyyyy

  • Phil

    No doubt this will take focus off of unlocking the iPhone 4 BB 02.10.04 any time soon.

    This cat-and-mouse game between Apple and all the brilliant hackers is becoming really tiresome for all iPhone consumers who want the freedom to do what they want when they want with THEIR property.

    I believe this is a major reason why Andriod OS will become the dominant mobile OS in the market in a relatively short period of time. While I absolutely love my iPhone, the hassle in dealing with Apple’s BS is always a nagging concern that I believe we would all rather not deal with.

    I am seriously considering trying out an Andriod based phone.

    • ric

      same ere was going to get i-pone 4,,, but now will defo be geten the samsung galaxy-s

  • shoo

    I remember when zibiri did this and the dev team called him the worst person on earth!!
    What does around. They are so full of themselves. Made the limera1n kid feel so bad about not having a college education he actually quit working on the iphone.

    DEV TEAM you suck. Thanks to commext they would have been history with all their college ed.

  • ifonix

    for shoo…
    only small people reacting as u r.
    thanx to DEV TEAM a big cuminity of iphone users have freedom to choose provider beside AT&T. install cool aap’s and get more out there iphone. and it is all free of charge!

    after JB and unlock 3GS now FW 4.1 BB 06.15.00 GPS work only when 3G or WI-FI is on..
    is downgrade to 05.15.04 will solve it?
    any way DEV TEAM, thanx

  • divious

    why downgrade to 05.15.04 when theres no unlock for the baseband and whats up with the iphone 4 unlock i see apple is making it harder and harder for the dev after i get unlocked regarless of features im staying put with my firmware

  • Mskreind

    I recently jail-broke and unlocked my iPhone 3GS using redsn0w and ultrasn0w respectively. I am currently on IOS 4.1, and baseband 16.15.00. I have noticed that since I completed this update, my iphone doesn’t ring when someone calls and the calls go directly to voicemail. Does anyone know how to rectify this problem?
    The only way I can get the phone to ring again is to reset network settings, but this only lasts for one or two calls and then it goes back to voicemail directly when someone calls.

    • mikeru_RO

      check Call Forwarding.. maybe it’s auto-fwded to Voicemail..

  • Speed2006

    From iPhone 4 any news? Still only 3, 3Gs, iPad.

  • mikeru_RO

    i haven’t been using GPS lately so much as to get to lose signal, but it doesn’t point my location as accurate as before..

    so this is GOOD NEWS!

  • gio

    is it true about limes0w? i’ve read that it will come out really soon and it can unlock iphone 4

  • Iphonewhite

    I had try to downgrade my 3gs from ios 4.2.1 to ios 4.1, but it was failed, i think it is due to Apple did not accept BB 6.15.0, luckly i had save my 4.1SHSH, finally i managed to downgrade it, if downgrade BB is applicable, it should be a big help to us.

  • viviz

    yes yes donwgrade i dont care if it gets locked again having an ipod is better then having an iphone which has a battery life for less then 3 hours and an iphone without push… :S

  • Koomoo

    Alot of iPhones I jailbreak n unlock had the SHSH files save so I would only flash the baseband to 6.15 n downgrade the OS to 4.0 to 4.1 for a untether jailbreak with jailbreakme.com or limerain every phone I would do has no problem at the moment with gps to battery or calling in to u

  • Koomoo

    I also heard of reseting the phone manually in settings helps with battery

  • Soso

    Hi fellas!

    I am writing here because I’m looking for help and mostly for answers to my question.

    I had jailbreak my iphone 3Gs when I think I had verson 3.1.2 or vers 4.0 of the iOS (done with jailbreakme.com).
    After I jailbreak, I noticed that I had a problem, couldn’t receive MMS (by the way i’m in Canada with Rogers). So everything was working perfect but i do receive MMS etc.. and when 4.1 iOS came out I decided to breakdown the jailbreak, bring my phone back to normal using only iOS. From there draining problem battery started. Then 4.2.1 iOS was released and i thought maybe this iOS might fixed the problem.. I did upgrade and even worst with battery draining.
    So now i have 4.2.1 installed & my Modem Firmware is 05.15.04
    I’m wondering if it is possible to Downgrade my 3Gs to either 4.0 or 4.0.1 iOS where everything was working well and so I can jailbreak back my phone?

    Also I did make a BACKUP of my iPhone with iTunes. Now the other question, let’s say i’m able to downgrade, is there a way to BRING BACK & Restore my backup as is to the downgraded iOS?

    And finally, let say I’m not able, I just go and downgrade my iPhone to earlier version like 4.0.1, can I jailbreak my phone and use another software to access my iPhone 3Gs backup I did to bring my SMS, Contacts etc.. back to the phone without syncing with iTunes?

    Thank you for your help guys!!!

    Much appreciate it!!!

  • YO YO YO

    Anyone has a good solution for battery drain after JB and unlock?

  • Iphonewhite

    My 3gs with jb ios 4.1, i also noticed that the battery drain off very fast then bfore, later i found the problem is because when my 3gs is in standby mode, it will lock automatically after 1 min & the screen also switch off, it is ok to save energy, but when i press the power button & let the screen display on, no doubt the 3gs still in lock condition, but the result is it will not turn to power saving mode which is keep the display on, unless i press the powrr button, in this condition of cause the battery will drain faster. Anyone know if this will happen in ios 4.2.1??

    • Soso

      Yes mate unfortunately with 4.2.1 it’s even worst on my side with the battery draining so fast. as you can read my post above yours, I have same problem and I think i’m gonna downgrade my iphone 3gs from 4.2.1 to 3.1.3 or something like that where is was working well.

      So you said you found the problem and the fact that the phone is in Stand By mode drains the battery faster? So are you suggesting to choose “NEVER” under Auto-lock?

      Thanx for confirming your solution. Let me know because if that fix the problem, then I won’t downgrade my 3Gs.

      Thanx mate

  • TMAC

    Thanks a bunch for workin on this fix. It is really appreciated. Thank you once again.

  • Iphonewhite

    Soso, sorry for the confusing in my earlier post, what i found in my 3gs ios 4.1 is that when my iphone in lock condition, the display will keeping in on condition & it will not auto off after 1 min, i believe in this situation the battery will drain off faster, so normally what i do is i have to press the power button to off the display everytime after making a call. I’m not sure are you facing the same problem with me??

  • ajuthms

    i had to upgrade the baseband to 6.15 as there was no other way to unlock my phone. I got the phone with ios4.2.1. now i need to downgrade from 6.15 to 5.15 as unlock is going to be released. if in future if any warranty problem arise, so i want to downgrade to 5.15.. pls help

  • Ali Imam

    Big Thanks to MuscleNerd and Sherif Hasim for their Big effort to unlock IOS 4.2, Now waiting for solution of battery drain issue. Good luck.


  • nouman tayyab

    i want to downgrade from 06.15.00 to 05.14.02 baseband in my iphone 3g im using ios 4.1

  • Shaz

    It is true that upgradation of base band to 6.15.00 vide redsnow has caused GPS of my newboot room 3gs non functional on 4.2.- I have tried every thing out in last two weeks starting from downgrade to redsnow apply about 4 times to get the GPS signals back but remained unsuccessfull – I tried to downgrade to 4.1 with redsnow,tinyumbrella,limera1n and finally with snowbreeze but no had no success till today- I know that Comex will just give me advantage to go to 4.2.1 but till the time baseband will not be downgraded to actuall iphones any of the baseband GPS issue will not be fixed and believe my iphone very handy for those who use GPS for coordinates and ofline maps- I am pleased to hear that Mr Muscle will do something for it and believe me its above .5 M people in world who are waiting for this –

  • I have jb my iphone 3gs ios,4.2.1,using Redsn0w,but upon trying using ultrasn0w to unlock it,it gets stuck on apple log,am having baseband 05.15.04,
    Hey Dev team first of all,i send my gratitude to you for your tireless works welldone with that,Well are we seeing something up to help us unlock ios,4.2.1,other than ultrasn0w cozs it doesn’t work with me here?

    • Iphonewhite

      Soso, when u using redsnow to jb your 3gs, you must tick the upgrade ipad baseband as well, with this it will upgrade your bb to 6.15, then Ultrasn0w should be able to unlock this, because bb 5.15 did not support by Ultrasn0w,. Hope this will help you.

  • help_please

    can someone please help me restore my iphone 3gs to 4.1. rite now im still on 4.2.1 and my baseband is 6.15.00. i think i saved my shsh blob on cydia. please need help from somebody tethered jailbreak is not really working for me and my gps is freaking dead after i upgrade and jailbreak ( idiot me )i just need a step by step on how to downgrade my ios please.

  • HuesoNet

    I want my GPS Signal back!!!! 😛

  • slick1474

    hi team…. has this baseband downgrade been given up on or are you guys still working on this? the slience is defeaning…. cheers and thanks for all the good work done…

  • Shane

    Seems Redsn0w have set us up and laughing at us suckers!!!

  • Jonblaze2000

    Ultrasnow 2.2 will be coming out tomorrow. Hopefully, it can unlock bb 05.14.04 for 3GS. I’ve been avoiding upgrading to bb 06.15 because of the warranty, battery drainage, and gps issues.

  • Jimilee

    I would like a battery drain fix please please please!!!

    • Franc 3Gs

      Remove all free app’s from iPhone and see what happend.I had same problem on my 3gs after an update of free app battery goes out in few houres.Un installing app solved problem.Try it’s free maybe will solve your problem to.

  • Tushar

    I have iphone 3g with following specification (Jailbreak & Unlocked)
    Version : 4.1 (8B117)
    Model : Mb
    Modem Firmware : 06.15.00

    and facing few problems so i want to downgrade it to Version 3.1.3 and any modem firmware which can be unlocked so please tell me how can i do it…

  • Mohammed

    Looking forward to this. I miss my GPS. Great work!

  • Khan

    I am also stuck on 4.2.1 bb 06.15 without GPS. I also dont see the option for internet tethering in my Iphone 3GS

  • dudledu

    I have 3G, and 3Gs, updated to 4.2.1 both , I dont know how to jailbreak the 3G , I did grenpoison on 3Gs it was simple but not sure , some applications dont do as it was on old one 3G , I dont know whether is for mac or windows bit confused , how ever I had the old one jailbreak for while but had problems with sound for long time so I didnt wanna do anythink until now when I did reboot to original state, I think the 3Gs is better but just dont know what to use to jailbreak as for windows cant find or just plain confused of searchin the right software I like it as jailbroken but now I feel like is not workin properly so I dont know , let me know if there is anythink at this time , to do 2/26/2011 thanks happy jailbreak I hope

  • Robinson Ogberaha

    i dont know how i did it but i think i have found a way to downgrade baseband 6.15.01…

    i just did it with my friends IPHONE 3g. i upgrade to baseband 6.15 to unlock and found out that push was not working, only for me to downgrade to 3.1.3, then upgraded to 4.1, then did a custom restore with snowbreeze custome ipsw 4.2.1, and found out that my baseband now reads 5.15.01… dont know how, but will try to repeat it again…..

  • dave

    hi guys my 3gs was running on 4.2.1 os i update bb to 6.15 to unlock. my phone was working fine until it crashed. the i tried to restore via itunes and saw 4.3 os update. only relaising my mistake. now my phone is stuck in recovery mode.ive tried ireb to get out of this but it wont work on jailbroken or un teatherd phones. can anyone sugest whai can do please

  • Spider

    I have 3gs, sound comes and goes after i updated with bb 06.15. any advice please 🙁

  • hari

    plzzz help me downgrade….my fone is still in he warranty but they wont take it back if its on ipad baseband…i want to downgrade it to normal iphone baseband soo they would agree to take this fone and give me a new one…because this phone is giving me problems…it heats up and stops respondingg very oftenn 🙁

  • darrel

    i am having problems with my gps on bb 6.15.0 would love to know when the downgrade software is available

  • domme

    yes plaese

  • teddy

    its been 5 months since this was promised to be fix.i rely on navfree for my day to day work.getting a navigational device is like having two the same time..please make a fix for this problem

  • teddy

    its been 5 months since this was promised to be fixed.i rely on navfree for my day to day work.getting a navigational device is like having two at the same time..please make a fix for this problem

  • iPhone

    Please !! I need my gps back

  • Iphonewhite

    I just upgrade my jealbroken 3gs to ios 4.3.2 by using custom firmware with bb6.15, then unlock using ultras0n 1.22, it looks great & most inportant is that it also fix the problem on battery drain off faster, now my 3gs battery atleast can last for 2 days. :-). But the wifi is not stable, most of the time ot can detect the wifi network & also show the correct dhcp ip address, but just can’t online.

  • Iphonewhite

    I had upgrade my 3gs to 4.3.2 by using custom firmware bb6.15 unlocked by ultrasn0w, it looks like 4.3.2 had fix the battery drain off issue.

  • Ivan

    Many frends of mine and me in Russia had upgrade to 06.15.00.
    It’ about 5-7 people. We all waiting for downgrade. I realy need a GPS back! Thanks!!!

  • RamRam67

    I have an iPhone 3GS on IOS 5. I jailbroke it and was about to downgrade from 5.15.05 to the ipad bb 6.15.00 until I read that I might lose gps. So please as soon as you find a fix for this, please share it. Thanks in advance.

  • RJ

    So what is the bottom line with this downgrade? Is it possible to fix the GPS functionality or not? I unlocked with ultrasn0w to use with T-mobile. Lost locations services and GPS functionality after that. Also, I don’t know if this has anything to do with it but after that unlock, I’m no longer able to place calls with the Vonage or Skype apps.

    • RJ

      Forgot to mention. iPhone 3GS with old bootrom, running on jailbroken iOS5 (GM) via redsn0w

  • Are They still working on fix for this issue or not?
    Since the jailbreak my GPS has been wildly inaccurate.
    None of my nav-Apps work anymore.. Im so anciaux for a fix.
    Just to know that They are still working on it.. Thanks for the reply in advance.


  • jona hart

    I think the problem is either not enough info on this OR can’t figure how to
    possibly some other thing who knows what

    • jona hart

      forgot to mention 3g and 3gs with this issue inaccurate and no function

  • Matt

    I have no service/no network on bb 06.15.00 how could i downgrade it ? I have unlocked my phone with redsnow and ultrasnow

  • elmewafy

    Is there a way back to base Band 6:15:00 5:15:05 knowing 3gs open two formal