As you may already know, when Apple releases new iOS firmware, say 5.1, they stop signing all older firmware, including 5.0.1 and below. This can be especially frustrating for all A5 (iPhone 4S, iPad 2) users, because currently those devices are impossible to downgrade.
Why is it important to downgrade your iPad 2 or iPhone 4S ?
Well unless you’ve been living under a rock, you all know that there is currently NO jailbreak, tethered or untethered for those latest A5 devices on the latest iOS 5.1 firmware.
For all other iPhone, iPod and iPad users the way around this, is to make sure you save your SHSH for 5.0.1 using TinyUmbrella, Cydia or other methods of backing up your SHSH.
The SHSH backup + TinyUmbrella will allow your device to downgrade to 5.0.1, and restore your ability to apply a fully untethered jailbreak.
This works like a charm for all devices, however it does not work for the iPad 2 or the iPhone 4S.
We’ve been waiting for a way to downgrade our iPad 2 for the last 12 months, we’ve yet to see anything. Even though it’s only been 6 months since it’s release, the iPhone 4S is in the same boat, it can’t be downgraded using the SHSH method.
However today, our very own Canadian friend from up the road iH8sn0w, announced that he’s found a way to downgrade all A5 devices, including the iPad 2 and the iPhone 4S from Apple’s latest iOS 5.1. The reported apticket system loophole will allow downgrade for all A5 devices, iPhone 4S, iPad 2 and even the New iPad.
We’ll be releasing information as soon as he’s finished with the mod, so make sure you follow iH8sn0w on twitter.