How to Fix iPhone X Face ID Not Working After Screen Replacement

The iPhone X shows an alert that says it is ‘unable to activate Face ID on this iPhone’.

When trying to setup Face ID on the iPhone X, we get the message 'Face ID is Not Available, try setting up Face ID later'.

Also, according to the feedback from our client, Face ID on the phone is available after being dropped. However, Face ID is not available after replacing of the display assembly.

Unavailable Face ID might be caused by improper operation when replacing the display assembly.

Check the Infrared camera and dot projector module under Microscope. Nothing goes wrong.

Let’s move to the Flood illuminator module on the earpiece speaker and front sensor assembly.

We can see clearly that flex cable next to the Flood illuminator module is damaged.

Now, we need to separate the earpiece speaker from the assembly.

Remove the ambient light sensor module flex cable afterwards.

Turn the flex cable upside-down and secure it again. Remove the Flood illuminator module.

Prepare a new flex cable. Apply some Paste Flux to the bonding pad and solder the detached Flood illuminator module.

Solder the detached ambient light sensor module flex cable.

Now we need to solder the earpiece speaker back to flex cable and get it installed to the display assembly. Secure with screws afterwards.

Go to Settings > Face ID & Passcode > Reset Face ID. Face ID can be setup successfully