Photo credit: lakewentworth (Flickr)
We’ve told you already how to backup those SHSH blobs, but you’re going to want to know how you can use them to get you out of a sticky situation. Let’s say you accidentally updated your iPhone to a version of iOS for which there’s no jailbreak yet and you want to downgrade your iPhone to an earlier iOS version. Provided you’vc an SHSH blob saved for the version of the firmware you want to load and it’s specific to your iDevice (since blobs are not transferrable), you can downgrade the firmware using the following steps.
- Close iTunes
- Open TinyUmbrella
- Connect your device
- Click Start TSS server on TinyUmbrella’s screen
- Open iTunes
- Shift click (Windows) or Command Click (Mac) the Restore button in iTunes for your device and browse to the firmware file you wish to restore to*.
- The verfication step will now phone Cydia servers for the SHSH blob rather than the Apple servers and allow a restore to commence.
- Once complete click Stop TSS server in TinyUmbrella and it’s safe to exit the program.
It’s worth noting that if you wish to downgrade your iOS version, it will not downgrade the device’s baseband. The baseband is essentially the bit of software which the sim card talks through to get on to the cellular network. If you rely on a jailbreak and sim unlock to use your network, you’re pretty stuffed if you need to downgrade until a newer baseband unlock is released – sorry, but you should have been more careful with your update process.