A phone or tablet feature that has completely stopped should be checked for a disabled permission or setting before assuming hardware failure. For iPhone Face ID, first clean the sensor area, remove obstruction and test unlock plus one supported app.
What this covers
- iPhone Face ID with this exact failure state
- Diagnosis across attention/appearance and screen protector versus camera obstruction and hardware
What it does not cover
Try in this order
0 of 4 completedCapture the exact failure state
ReversibleCheck whether the feature is grayed out, missing from settings entirely, or present but unresponsive when used. Expected behavior: recognize the enrolled face through an unobstructed TrueDepth system under supported conditions.
Isolate the component boundary
ReversibleClean the sensor area, remove obstruction and test unlock plus one supported app. Test the same feature in a different app that uses it, and with recently installed apps disabled or in Safe Mode. Boundary to separate: attention/appearance and screen protector versus camera obstruction and hardware.
Correct only the proven cause
ReversibleUpdate, reset and re-enroll Face ID only after passcode and app credentials are available. Re-enable the permission or setting, or update/reinstall the one app where it fails.
Verify and stop safely
ReversibleConfirm the feature works from a cold restart in at least two different apps. Service after impact, liquid or a TrueDepth unavailable message that persists.
Evidence ledger
Sources behind this answer
Exact questions