Error 53 makes my sister's iPhone 6 brick
Because the iPhone was serviced by a third-party, the phone is bricked. Apple will issue an out of warranty replacement, but it will be quite expensive. (It is an out of warranty replacement because the technician voided the warranty when he replaced internal components.)

Apple is not just doing this for fun. It keeps your biometric data secure. If someone at the mall, for example, replies your Touch ID sensor with another one, he can gain access to the iPhone and your information is not secure. While it may be frustrating, there is a good reason it happens.