A phone or tablet problem starting right after an OS update, a new case/accessory or a restored backup should be checked against that change first. 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
ReversibleNote the exact update version, accessory or backup date, and confirm the feature worked immediately before it. 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 with the new accessory removed, or check the update's known-issues note for the exact symptom. 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. Reset the one setting the update changed, or replace the incompatible accessory.
Verify and stop safely
ReversibleConfirm normal operation with the change present for one full day of typical use. Service after impact, liquid or a TrueDepth unavailable message that persists.
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