Symptoms
- Face unlock stopped right after a screen replacement
- Error message about the sensor or 'unable to activate' unlock
- Everything else on the phone works normally
Likely causes
- CommonFront sensor module not transferred to the new screen during repairSome repairs require moving the original sensor housing to the replacement screen, and skipping this breaks face unlock.
- CommonNon-genuine replacement part lacking proper pairingAftermarket screens sometimes can't fully communicate with the face sensor system.
- PossibleSoftware needs recalibration after the repairA restart or settings reset sometimes restores function if hardware is intact.
What to do
- Restart the phone first in case it's a simple software hiccup after the repair.
- Go into settings and try removing and re-setting-up face unlock from scratch.
- Check if the repair shop mentioned whether the original sensor housing was reused.
- Contact the shop that did the repair, since this is often fixable by reseating or transferring the sensor component.
- If the shop can't resolve it, an authorized repair center may be needed since face sensors are tightly tied to the original hardware pairing.
When to call a pro
Go back to the shop that did the screen repair first — this is a known issue when the sensor housing isn't properly transferred, and many shops will fix it under their repair warranty.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.