iPhone 4 iOS 4.2.1 Jailbreak is now possible by GreenPois0n RC5 but many people are afraid to update because they might lose the Ultrasn0w unlock. There is a work around to preserve Ultrasn0w unlock of Modem Firmware 01.59.00 and update to iOS 4.2.1 on your iPhone 4. Preserving the unlock will enable you to use iPhone 4 on different carriers without any restriction. You can follow our guide on how to preserve unlock and update to iOS 4.2.1 on iPhone 4.
Warning: This method only works for iPhone 4.
Requirements:
Unlocked iPhone 4 on any older iOS version than iOS 4.2.1.
Tinyumbrella ( Download from here)
iPhone 4 iOS 4.2.1 (Download from here)
iPhone 4 iOS 4.2.1 update without BaseBand Upgrade
Step 1:
Run TinyUmbrella.exe
If Windows shows any Firewall notification, select both check boxes and click Allow Access. (see snapshot below)
Step 2:
Your iPhone 4 should be connected to PC and make sure TinyUmbrella has detected the type of device and its iOS version.
Note: Also save your iOS 4.2.1 or whatever iOS version you are running save its SHSH Blobs by clicking on Save SHSH. This will ensure we can downgrade back incase something goes wrong
Step 3:
Click on Start TSS Server and make sure it does not give any error.
When TSS Server is “running” successfully, TinyUmbrella will force quite iTunes and leaving TinyUmbrella running. Make sure the TSS Server is running by checking TSS server is running under the Log tab.
Warning: This is very important! If you face any error till now DO NOT continue. Your restore will not work if the TSS server cannot be started.
Step 4:
Now run iTunes.
We will have to manually update to iOS 4.2.1. Hold down Shift key (on keyboard) and click Restore
Browse for the iOS 4.2.1 IPSW file you downloaded at the beginning of this tutorial and click Open.
Now Click Restore to begin update your device to iOS 4.2.1.
Step 5:
iTunes must give error 1013. We want this error because it ensures the baseband has not updated.
Click Ok and close iTunes. You can now skip to Step 7.
Important: If you get a 16XX error then try entering DFU mode by following Step 6 and then go back to Step 4. If you did not get error 1013 after restore, it means your baseband was updated. This happens when the TSS server was not running OR you updated without TinyUmbrella OR you are using any OTHER device than iPhone 4.
Step 6: (only if you get an 16XX error after restore)
You need to put iPhone 4 in DFU mode. Hold down both the Power and Home buttons for 10 seconds, then release the Power button and continue holding the Home button for another 5 seconds.
Jailbreak iPhone 4 iOS 4.2.1 using GreenPois0n RC5
Step 7:
We are almost done. Now you can use GreenPois0n RC5 to Jailbreak iOS 4.2.1 and bring your iPhone 4 out of DFU Mode. Follow our step by step iOS 4.2.1 Jailbreak guide here.
**Note: You do not need to put the device into DFU mode after press the Jailbreak button in Greenpois0n as we have already done this 
Unlock iPhone 4 iOS 4.2.1 using Ultrasn0w Unlock
Step 8:
Congratulations, you have successfully updated to iOS 4.2.1 without upgrading your BaseBand version. Now unlock your old baseband using this Ultrasn0w tutorial.
[via]
You can get updates by following us on Twitter or become a fan on Facebook. Meanwhile you can also subscribe to our Daily Email Newsletter.
Related Stories
Unlock iOS 4.3.3 using Ultrasn0w 1.2.3 for iPhone 4, iPhone 3Gs
Unlock for iPhone 3G/3Gs BaseBand 05.15.04 and iPhone 4 BaseBand 01.59.00 is completed
iPhone 4 Unlock to be released after iOS 4.3 and 4.2.5 are Public
Download Ultrasn0w to unlock iOS 4.2.1 on iPhone 3G and 3Gs
I jailbroke my iPhone 4 running iOS 4.2.1 with greenpois0n RC5 and it caused me some troubles, so I restored it using TinyUmbrella and now I’m on 4.2.1 with baseband 03.10.01 but the device is still jailbroken. How can I restore it to factory-factory and not a functional yet jailbroken device. I want to go back to 4.2.1 in a non-jailbroken state. Any thoughts?
baseband does not effect jailbreak. Unlock depends on baseband version.
How Can i unlock my iPhone 4 running iOS 4.2.1 with baseband 03.10.01
There is not unlock for baseband 03.10.01. You have to wait for new unlock.
Do you kno maby,when? is it gona take long till they find a new way to unlock it?
i have the same problem as jim.
try green poison rc6. mine same baseband and firmware
I jailbroke my iphone 4 running IOS 4.2.1 with greenpoison, my baseband band is 03.10.01.
How unlock my iphone?
hey nicholad have you got your phone unlocked…?
my aunt had an unlocked Iphone 3GS.. she upgraded to regular 4.2.1 and the phone is no longer unlocked so I updated to greenp0ison on my aunts phone. how do I unlock it from there? is it possible
this guide is only for iPhone 4
You need to use redsn0w to flash the baseband to 6.15.00 then jailbreak and unlock with ultrasn0w
This only works for 3GS and 3G. You can’t flash the iphone 4 baseband to 6.15.00.
Will this work with newest version of itunes which i believe is 10.1.2? or do i have to have older itunes versions of 10.1.1? i read somewhere else that it does not work with newest versison of itunes just trying to confirm that.
yes it works with iTunes 10.1.2
do you are iranian? i need help for unlock iphon 4 but ican not good english, can you help me
100%
thank you
Will this work with Iphone 4 iso 4.1 and baseband 02.10.05?
Its work for me but some minor errors i find solution through google… Thanks Newsden.net
dude can v unlock iphone 4 with base band 3.10.1
I have used tinyumbrella to save my ShSH I have Iphone4 with 4.0.2 (8A400) (1.59.00 BB) and wish to update to 4.2.1. The only thing that worries me is that the saved SHSH have save only the following: 4.1 SHSH, 4.2.1 SHSH, 4.2b3 SHSH, 4.3b2SHSH, 4.3b3 SHSH. it said I was to late for 4.0.2 SHSH. Thus my question can I update with TinyUm; running with these other SHSH files to preserve my BB 1.59.00 can you advise
No replies so I was confident that it would work. and it did and preserved the base band to 1.59.00 happy and it took a couple of time to get it right. Good luck any others hope this helps you
hi Grahame,
may i know how you preserve your baseband to 1.59.00? please let me know tq =)
Can we unlock iphone4 bb 3.10.1 n it’s version 4.2.1
Plzz help
Great find, however I now seem to be stuck in dfu mode. any ideas guys? iphone 4 4.2.1.
I have done everything that is possible to unlock the iphone 4 4.2.1 but it did not work. I did the following:
1. Downloaded the firmware and the JAILBREAK 4.2.1 tried (WINDOWS)(3).
2. Followed the steps and got Cydia on iphone through Jailbreak.
3. Once on Cydia, I went to the sources > repo666.ultrasn0w.com and downloaded the application and restarted the phone.
I have tried the above steps several times. Got new software installed and retried it. and tried the above steps again.
Pl help!!
Hello Brother u show us very clreary everything very nice u did a great job, brother i wana ask you do you know how to downgrade 03.10.01. to any other baseband iphone 4 i can’t unlock it even i try downgrade frimware from 4.2 to 4.1 but still i can’t have any solution ?….Tnx
Hi all
)
Well I need some help before I brake my Iphon e4
I have Iphone4 with version 4.1
modem firmware 02.10.04 and everyone is telling me that it can’t be unlocked.
Anysuggestions ? HELP
Hi,
i Have iphone4 4.2.1 lock by vodafone (firmware 03.10.01 )
i just follow your instructions but my firmware not been change and i can`t use any other sim, could you please advice to unlock vodafone sim?
no unlock exist for your baseband version yet,join the club of iphone owners that have been waiting for MONTHS for a unlock to be released.
How Can i unlock my iPhone 4 running iOS 4.2.1 with baseband 03.10.01
Not yet Nhon Ly ,wait untill Apple release new 4.3 version .They said around fist of March but who’s know .
all you guyz trying to unlock 4.2.1 w/ baseband 03.10.01, there is no unlock till 4.3 is released…in March hopefully
Dont bother jailbreaking 4.2.1 w/baseband 03.10.01 , no unlock yet
I have an Iphone 4 4.2.1 with firmware 03.10.01. Could i use the Greenpoison jailbreak without any consequences? or should i just wait for the day till someone releases a new greenpoison version that could jailbreak and unlock at the same time??
When i start the TSS server, it says accepting connections…can i still go ahead with the update or do i have to wait until connection is accepted?
Thks
Has anyone tried this method and succeed?
jail break’s done with my iphone 4, 4.2.1 bb 3.10.1. wait for unlock ultrasn0w.
I have Iphone4 with version 4.1 modem firmware 02.10.04. Can it be unlocked?
so with this jailbreak can we use an iphone 4g 4.2.1 on Tmobile?
Hi, I followed the tutorial to the “t” (promise!) and now I get a “connect to itunes” message and it says my sim isnt valid. Now I can’t restore or anything. PLEASE help.
Did You Use An AT&T sim?
hi please can any one tell me when will be able to unlock iphone 4 4.2.1 thanx
i already restore , then greenpois0n jailbreak and my iphone fail to get
so i cant get into my iphone ):
what should i do ? help ?
requirements is unlocked iphone 4??? what if not yet unlocked help please Thank you!
“Requirements:
Unlocked iPhone 4 on any older iOS version than iOS 4.2.1.
Tinyumbrella ( Download from here)
iPhone 4 iOS 4.2.1 (Download from here)”
is i phone 4 4.2.1 unlock is available
I have Iphone4 with version 4.1 modem firmware 02.10.04. Can it be unlocked?
i have an iphone 4 with version 4.2.1 and with firmware 03.10.01 is there any way to be unlocked?
Can I jailbreak my phone from the phone it’s self using the wi-fi on the phone? It’s running on iOS 4.2.6
you must instal yellowsnOw + ultrasnOw to unlock iphone 4 4.2.1 03.10.01.
Hi,I hv an iphone 4 4.2.1 BB 03.10.01 and unlocked by gevey sim.Now I want to upgrade the iso 4.3.3.What will be the procedure,I just connect with itune and upgrade ? My original nocontact sim was AT&T.My question is,what I need to do-remove my present sim and insert the original one and upgrade or just connect and upgrade(Before unlock,I activate my phone using the AT&T sim).Another thing if I upgrade 4.3.3 will my BB change ? Pls help me.
–Regards