Just for clarification, if you do not save something called SHSH Blobs, it can be difficult to make changes. This simply means it is impossible to do upgrades/downgrades if you have not saved your Blobs. And you CANNOT use Blobs from another device because they are tied to a specific device.
You must save your Blobs before Apple stops signing the firmware.
Here is a link that will explain the issues and problems:
http://www.ipadforums.net/ipad-hacking/24323-shsh-blobs-frequently-asked-questions-updated.html
Or . . .
http://www.ipadforums.net/jailbreaking-hacking-tutorials-how-guides/26815-how-downgrade-your-ipad-ios-firmware.html
I suggest you digest both. The links are easy to follow tutorials that might help you.
SHSH Blobs are digital signatures Apple provides that authorize the installation of a particular version of IOS on your device. A set of blobs are required before iTunes will install a firmware file on your iPad.
iTunes will not let you install, update, or restore IOS on your iPad without valid SHSH blobs. There is no way to circumvent this security measure. So no blobs means no install.
--- In iPad@yahoogroups.com, "Fabio" <fabio_dmaximo@...> wrote:
>
> Hi guys, I have an iphone with an IOS version 4.2 (8C134b) 7.10.00 firmware model.
> I tried to Jailbreak redsn0w_win_0.9.6rc19 through to version 4.3.3. As through Itunes was not possible to restore to 4.3.3 (error 3194) because Apple allows only the latest version 4.3.5, I tried to skip this step and run directly from iTunes redsn0w, select the downloaded 4.3.3 ipsw iClarified site, put it in DFU mode and tried to make the case.
> The device was restarted and after the icon appeared, but white is not possible to run it. Some problems arose with the system.
> I decided to upgrade to version 4.3.5 and try to downgrade to 4.3.3.
> How can we not saved the hush, somebody could help me with dowgrade please?
> Is it possible to do downgrade without locking the device?
> If you can send a step by step thank you very much
> Regards,
> Fabio
>
