If you¬†accidentally¬†updated your iPhone 3GS to iOS 6 without preserving your old baseband then your baseband would have changed to 5.16.07 which can’t be unlocked with tools like Ultrasn0w or hardware solutions like Gevey SIM. Fortunately, you can downgrade your old Bootrom to BB 5.13.04 by first installing iPad BB 6.15.00 and then downgrading to 5.13.04. ¬†Before proceeding to the tutorial we would like to inform you about the risks¬†involved¬†in the process and other important info.
- The process is a bit complicated specially for newbies. Follow this guide in leisure time and don’t do anything in a hurry. Proceed to this tutorial at your own risk. We will not be responsible for any damage to your device.
- This guide is only for old Bootrom iPhone 3GS owners. If your 16GB or 32GB phone was manufactured after week 35 of 2011 then chances are pretty high that you’ve new Bootrom. Check the serial number of your device to verify it. If digits 3-5 of its Serial Number are 134 or later, then don’t install BB 6.15.00 as it’ll brick your device. 134 refers to week 34 of 2011. Similarly, 8GB iPhone 3GS owners with model later than week 28 of 2011 should avoid this tutorial.
- Baseband 06.15.00 might result in loss of GPS functionality but iPhone Dev Team has fixed this issue in latest Redsn0w versions. Now, you can get your GPS back after downgrading to 5.13.04 with Redsn0w. Although, this problem is now solved but we still wanted to tell our readers about this possible situation.
- Baseband 5.13.04 can be unlocked with Ultrasn0w.
- It’s impossible to directly downgrade to 05.13.04 from 05.16.07. You must have to downgrade to iPad BB 06.15.00 first.
We’re hopeful that you’ve clear understanding of risks and consequences now. Let’s start the tutorial. Once again, remember that proceed at your own risk.
Part 1: Downgrading iOS 6 to 4.1
Luckily, Apple is still signing iOS 4.1 which means that you can easily¬†downgrade your phone from iOS 6. It’s a necessary step to install baseband¬†6.15.00.
1. Download iOS 4.1 for iPhone 3GS from this link.
3. Download¬†TinyUmbrella for Windows or Mac from here.
4. Uninstall your current version of iTunes and install¬†iTunes 10.4.1 from below links.
If it says that you’ve new version of iTunes already installed then search for the file “iTunes Library.itl” from Windows 7 / Vista start menu search box and change it to “iTunes Library.id.backup”. Run the exe file again.
Backup important data like Contacts, Apps and Pictures. Take out your SIM Card
5. Now you’ve to put your iPhone into DFU mode. Do it by following below steps.
- Switch off your device.
- Hold down both “Home” and “Power” button for 10 seconds.
- After 10 seconds, release Power button but hold onto the Home button for another 10 seconds.
- If the screen goes black then it’ll be the indication that you’re in DFU Mode now.
6. Connect your iPhone to the Computer and run iTunes.¬†Hold the “Shift” key¬†on Windows and “Alt” Key¬†on Mac, click on “Restore” button . Point it to iOS 4.1 IPSW file you downloaded in Step 1. Your device should be restored now to iOS 4.1.
If you get error 3194 then you can get rid of it by exiting iTunes and editing the hosts files in Windows and Mac. This file is present in below folders. Open these files as Administrator if you’re running Windows.
Add below line at the end of the file and save the file.
Try the Step 5 and 6 again. Remove the line you just added after restoring successfully.
If you get error 1015 with recovery loop then you can use “Exit Recovery” function in TinyUmbrella to end it.
Part 2: Install iPad Baseband 6.15.00
7. Now run Redsn0w 0.9.6rc18 you downloaded in Step 2.
8. Locate and select iOS 4.1 firmware file for your iPhone 3GS.
9. Check “Install Cydia” and “Install iPad Baseband” options. ¬†Again we would like to remind our readers that please don’t install it if your iPhone 3GS was manufactured after week 28 of 2011. It can brick your phone and you can’t fix this problem with any software.
10. Put your device into DFU mode by following on-screen instructions.
11. After some time, your phone will downgrade itself to iOS 4.1¬†with iPad baseband 6.15.00. We strongly suggest you to use “Make My Life Easier” option in Cydia to save SHSH Blobs for your current firmware. With this option, you would be able to downgrade to iOS 4.1 even if Apple stops signing it in future.
Part 3: Downgrade Baseband 6.15.00¬†To 5.13.04
13. Go to “Extras” and choose “Select IPSW” option and choose the iOS 4.1 file you downloaded in Step 1.
14. Now you need to do controlled shutdown of your phone with “Slide To Power Off” function. This is an important task to perform because it avoids¬†mount issues while running Ramdisk.
15. Go back to Main Menu and select the “Jailbreak” button. Check “Downgrade from iPad Baseband” option but don’t check “Install Cydia” option. Select¬†“Next” button and get into DFU mode by following on-screen instructions.
16. Flashing Baseband will take some time. After a few minutes, your iPhone 3GS will be downgraded to¬†5.13.04 on iOS 4.1.
If you’re happy with current Apple firmware and want to unlock it with Ultrasn0w then continue reading our tutorial. If you want to update to iOS 6 first while preserving¬†baseband and then unlock, skip Part 4 steps and read the rest of the post.
Part 4: Ultrasn0w 1.2.7 Unlock
17. Open Cydia and search “Ultrasn0w”. If you can’t find it then add the below source to Cydia.
18. Install Ultasn0w 1.2.7 and reboot your device.
19. Insert the SIM card and Turn off 3G. You should see carrier signals on your iPhone 3GS now.
If you would like to update to iOS 6 without loosing unlock then you can do it by following our tutorial on updating to iOS 6 while preserving baseband. After updating, you can read our Ultrasn0w fixer guide to unlock iPhone 3GS on iOS 6.