Apple re-issues iOS 9.2.1 to fix iPhones bricked by Error 53
From ComputerWorld: Apple today re-issued iOS 9.2.1 to fix the "Error 53" that had crippled iPhones whose owners had replaced some parts themselves or had a third-party shop do repairs.
The new iOS 9.2.1 will only be served to users who update their iPhones through iTunes on a Mac or Windows PC...