Apple has apologized to users whose phones were bricked by a recent update that interpreted third-party repairs as attempts to hack the device. It also released a new update that revives the dead handsets through iTunes.
Some customers' devices are showing 'Connect to iTunes' after attempting an iOS update or a restore from iTunes on a Mac or PC. This reports as an Error 53 in iTunes and appears when a device fails a security test. This test was designed to check whether Touch ID works properly before the device leaves the factory.
Today, Apple released a software update that allows customers who have encountered this error message to successfully restore their device using iTunes on a Mac or PC.
We apologize for any inconvenience, this was designed to be a factory test and was not intended to affect customers. Customers who paid for an out-of-warranty replacement of their device based on this issue should contact AppleCare about a reimbursement.