I currently work at a cell phone repair shop, and have been since my sophomore year of college (approx 5 years). Error 53 is an issue with iPhones 5s and above (the ones with the fingerprint scanner). These home buttons are married to the motherboard which is what allows iTunes/Apple to recognize if a new one has been installed. When getting a screen replaced, there is no reason not to use the original home button. The home button can be transferred to the new screen. So why does Error 53 happen? Shoddy repair jobs. The buttons and their flexes (flat bundle of cables) are very fragile. Even the slightest tear can render a flex inoperable. When a repair shop has to replace a home button it's because they were removing the home button too fast and tore the flex. That or they were trying to snag an OEM part, which is a shady practice. Error 53 sucks. But if a repair shop is going a good repair, there shouldn't be an issue.