To be perfectly clear, following the repair, the phone would still work perfectly until iOS 9 was installed. At that point, the error message would appear on the screen and the phone would be bricked. Photos, data and other content were lost forever. Some believe that this is taking place when iOS 9 starts looking for original components that are no longer on the phone. When those parts can't be found, the user is locked out and the only remedy is to purchase another iPhone.
Those left with a bricked iPhone are blaming Apple for not passing along details of this issue in advance to consumers and repair shops. Many believe that the error 53 issue was created to force iPhone users to have their handset repaired by Apple.
Whatever the reason, let this be a warning to you. If your iPhone 6 or iPhone 6 Plus is damaged, you might want to consider allowing Apple to handle the repairs. Otherwise, "error 53" could leave you with an expensive paperweight.