In case you have an iPhone 4 or even a 3GS that you’d like to update to the newest iOS available, you should know first that there are several ways of doing it and that, depending on the form, the result will vary. So why would you want to upgrade just the firmware and leave the baseband intact ? To allow you to later on unlock your phone through UltraSn0w or Gevey SIM, and that’s obviously a major plus.
RedSn0w has a feature that lets you do it, but bear in mind that only for iPhone 4 or iPhone 3GS, as iPhone 5 or the 4S are not yet supported. So check below what you need to do to accomplish it after downloading RedSn0w.
- First, extract the RedSn0w.zip file to obtain the RedSn0w.exe. Then, run the RedSn0w.exe file and click Extras in the menu, and after that, click on Even More. Finally, click the Restore button.
- Now, you must click on the IPSW button.
- Afterwards, browse and select the download iOS firmware file that you’d like to update to and then click on the Open button. RedSn0w will then ask you if you’d prefer to “Prevent Baseband Update“, so you’ll have to click Yes so the baseband stays unaltered, which is your aim.
- Now that you have told RedSn0w what you want the app will tell you that the DFU mode is required, so click on the OK button. After this, you will have to connect your equipment to your computer (this works in both Mac and PC), turn it OFF and click the Next button in RedSn0w. Now you’ll just have to follow the instructions that appear on the screen to enter the DFU mode.
- First, release the Power button for 3 seconds, and then, while still holding the Power button, also hold down the Home button for about 10 seconds. Now, still holding the same Home button, release the Power button BUT keep holding Home until RedSn0w detects your phone.
- Your phone is now on DFU mode, so RedSn0w will exploit it using Limera1n. After that, it will prepare an image restore, and then restore the equipment with new firmware; finally, it will warn you when the restore process is complete. And that’s that!
- After the process is complete you will get this screen , of successful restoration
It’s quite simple and handy, as you surely don’t what to miss the opportunity to unlock your phone sooner or later, so give it a go as explained above and you’re set.