“Face ID is not available” after a drop: what happened, and what can be repaired
The phone works, but it no longer recognises you, and the Face ID setting is greyed out. It isn't necessarily permanent.
Face ID relies on a set of three elements: the infrared camera, the flood illuminator and the dot projector, linked to the logic board by flex cables and paired to the processor. When the message “Face ID is not available” appears, one of the three is no longer responding.
After a drop
The most common: the Face ID assembly's flex cable has come unstuck or torn, or a connector has lifted on the logic board. Repairable by micro-soldering, keeping the original modules, therefore keeping Face ID.
After a screen replacement
On the iPhone X to 12, part of Face ID (the projector or the camera depending on model) is attached to the front assembly. If a repairer damaged it or replaced it with an unpaired new part, Face ID is lost. We can often repair the damaged flex by micro-soldering; delicate work, but the only kind that keeps the function.
What nobody can do
Replace the dot projector or the infrared camera with a new part: they are paired at the factory to the processor, and only Apple can re-pair. If the module itself is destroyed, Face ID won't come back, here or anywhere. We tell you frankly at the diagnosis, and the phone remains usable with the passcode.
Fixed price for component-level repair: 149 €, not charged if it can't be repaired.
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