Due to the design of the iPhone 13, FaceID functionality may be lost if the screen is not replaced by Apple or an affiliated repair shop.
iPhone 13 screen replacement means no more Face ID… definitive proof
iFixit has discovered that attempting to replace the iPhone 13’s screen, a common smartphone repair, can disable FaceID entirely. So unless you take your iPhone 13 to an Apple Store, a repair shop in Apple’s Independent Repair Provider network, or a shop with more advanced tools, you run the risk of losing that functionality.
The culprit is a small microcontroller chip that is linked to the phone's screen, and it needs to be synchronized to work properly.
Apple does not yet offer independent repair shops a way to replace or pair displays and microcontrollers, making the process nearly impossible for smaller businesses.
