How To: Downgrade iOS 4.3 to iOS 4.2.1, 4.1 for iPhone, iPod & iPad
How To: Downgrade iOS 4.3 to iOS 4.2.1, 4.1 for iPhone, iPod touch and iPad | TechnoBolt
Apple just released iOS 4.3 for public with numerous new features. As you might know Apple Stop signing old firmwares for restoring to it. So all those people who are stuck to iOS 4.3 and want to downgrade will need SHSH Blobs to downgrade from iOS 4.3 to iOS 4.2.1, 4.1 or lower. So here is a guide on how to Downgrade iOS 4.3 to iOS 4.2.1/ 4.1 on iPhone, iPod touch and iPad.
obviously if you're on 4.3 then you will not be able to see this ^. but this when if you remember selecting the "make my life easier" option in Cydia matters, or used another method to save blobs NOTE: This guide will only work if you have shsh blobs saved for the particular firmware you are downgrading too.
To find if you have shsh blobs for particular firmware or not, go to cydia and check above the Welcome to cydia you will see it (SHSH Blobs) for particular iOS.
can anyone confirm if Apple has indeed stopped signing 4.2.1?
personally, i have upgraded to 4.3 and downgraded to 4.2.1 (twice) and this method worked both times. however, if you run into difficulties please try to research as much as possible before posting useless threads
if anyone else has successfully downgraded, or knows about it, please feel free to add to this thread