Every time Apple releases a new iPhone firmware, a few people don’t pay attention and update their iPhones to the newest version without thinking, this kills their Jailbreak and Unlock of course. If you’re one of those people then here’s how it might be possible for you to downgrade back to OS 3.1.2…
In the past, to downgrade an iPhone firmware, you’d simply download the older version of the OS directly and then use SHIFT + the restore button in iTunes to pick the older firmware. Unfortunately Apple has recently stopped signing any of the previous firmware versions, making it impossible for you to install them on your phone after upgrading.
This problem was forseen by Saurik, the creator of the Cydia App Store for Jailbroken phones and he created a system that keeps a set of files called SHSHs stored for you on a remote server. If you’ve installed the Cydia App Store in the last few months, you were most likely asked if you’d like to keep your SHSH’s on file. If you did then you’re able to downgrade without a problem.
To see if you have them on file for your device, launch Cydia and look at the very top of the screen. It should say: “This device has SHSHs on file for iPhone OS: 3.x″. If it does, then you’re all set.
To continue to downgrade your device, follow this tutorial, just substitute the firmware’s that you need downloaded from here.
3 Responses
I have downloaded iPhone application and it’s really a very useful for the iPhone as well as iPod..
so if you dont have the files you cannot downgrade ?
If you don’t have them on file either yourself or with Cydia, you can’t downgrade.