I repair iPhones for a living and after iPhone 6 was released I've come across iTunes error 53 when updating/restoring iPhone 6's.

Error 53 is not listed anywhere and I cannot find any guides or info besides to take it back to Apple store, which is not an option.

Does anyone know how to fix this?

I now know that this is a touch ID related problem. I also know why error 53 appears. If you change the screen of an iPhone 6 while the power is still on you will get error 53. You can also get error 53 if the iPhone is water damaged.

However, I haven't found an answer for the problem yet.

I've tried to restore, hard reset, DFU restore, change the home button and restore, restore without home button, restore with original home button, Logic board in test cabinet and restore. Nothing helps.

Has anyone had success with error 53 yet?

UPDATE 2/18/16 EDIT by mayer:

Sorry - I need to stick this answer & edit in here:

Confirmed: Apple’s Error 53 Fix Works

This morning, Apple apologized to its customers and admitted that Error 53 was a mistake—as opposed to a deliberate security feature. They also released a patch to iOS 9.2.1 that purports to fix Error 53—un-bricking phones disabled by the problem and preventing it from happening in the future to phones repaired outside of Apple's network.

Of course, we had to test the repair procedure ourselves. We’re pleased to report that the fix successfully fixed our Error 53ed iPhone 6s, and the process is refreshingly straightforward.

Visit our blog for more on our analysis.

http://ifixit.org/blog/7924/error-53-fix...

Nice job, Apple! Rolling out a fix is not only a win for consumers—but a clear victory for the right to repair your stuff. But there’s still a lot of work left to do to ensure that owners and independent repair shops have all the parts, tools, information, and support they need to fix products. And we’re going to continue to fight these battles publicly, in front of the Copyright Office, in front of lawmakers, and wherever else they need to be fought.

You can head over to Repair.org to check out all the other ways we’re working to make sure people can fix stuff when it break.

If you have any questions, or would like to request an interview, please email Kay-Kay Clapp at kaykay@ifixit.com.