If you update iPhone 4 to iOS 4.2.1 then your baseband will also upgrade to 03.10.01 and at the moment you can’t unlock this baseband. Here is the solution, how to update iPhone 4 to iOS 4.2.1 without updating its baseband. We can achieve that using TinyUmbrella. Lets see how to preserve iPhone 4 baseband 01.59.00 using TinyUmbrella while updating iOS 4.2.1.
Note: Use this guide to update iOS 4.2.1 on iPhone 4 only.
Step-1
- Download TinyUmbrella OSX | Windows
- Download iOS 4.2.1 for iPhone 4
Step-2
Connect iPhone 4 with computer
Run TinyUmbrella and hit the “Save SHSH” button,
See the SHSH for iPhone 4 4.2.1 in the list on TinyUmbrella
Step-3
Now hit the “Start TSS Server” button and keep it running
Step-4
Update iOS 4.2.1 iPhone 4
Now its time to update iPhone 4 to iOS 4.2.1.
Note: Before updating iOS make sure there is no error occurred in TinyUmbrella, click on Log tab, if TSS Server is running then you are good to move on the next step.
Run iTunes, Select your device from the left panel.
Hold down Shift key from keyboard on Windows or Alt/Option key on Mac and then press the “Restore” button in iTunes.
Now browse and select the iOS 4.2.1 firmware file for iPhone 4 that you have downloaded in step-1
You will see this 1013 error – baseband update failed, this is what we are doing.
You have successfully update iPhone 4 to iOS 4.2.1 without updating its baseband.
Now if you want to jailbreak iOS 4.2.1 check this: How to Jailbreak iOS 4.2.1 iPhone 4 Untethered
How to see iPhone baseband?
Hi, I have an iphone 4 Jailbroken using jailbreakme.com & unlocked using ultrasn0w. I have a cut down O2 sim (the iphone was locked to Vodafone in the UK).
My Version is 4.0.1 (8A306)
Modem Firmware 01.59.00
Model MC603B
OSX 10.6.6
Am I correct in thinking that if I use this method to update my iphone 4 software, the unlock will remain?
Many thanks,
Andy
Yes, you can use this jailbreak method on your iPhone 4. Perform step-2 and 3 without any error to stop upgrading Baseband.
If you need any help, just reply.
hi my phone had 4.0 OS with baseband 1.59.00. I followed all the steps mentioned above correctly in order to upgrade to 4.2.1. After i got the iTunes error ‘Could not be restored’ my phone is showing this ‘Connect to iTunes’ logo. Can u tell wat to do next
See the last screenshot in the post, if you are getting the same error then you don’t need to worry about it, just follow the link after screenshot to jailbreak your iOS 4.2.1 on iPhone 4.
Feel free to reply.