Face ID is one of the most convenient features on your iPhone. You glance at your phone, and it unlocks. You authorise Apple Pay with a look. You log into apps without typing passwords. But when Face ID stops working, it's more than an inconvenience – it can be a security and usability nightmare.

In this guide, we'll explore the most common reasons why Face ID stops working, what you can do to fix it, and when you need professional repair. If you're in Nairobi, we'll also show you how to get your Face ID restored quickly and reliably.

How Face ID Works – A Quick Overview

Before we dive into problems, it helps to understand how Face ID works. Face ID uses the TrueDepth camera system at the top of your iPhone. It projects over 30,000 invisible dots onto your face and creates a mathematical 3D map. This map is stored securely in the Secure Enclave – a dedicated security chip that never shares your face data with Apple or third parties.

The TrueDepth system is made up of several components:

• Dot projector – Projects 30,000+ infrared dots onto your face.
• Infrared camera – Reads the dot pattern to create a 3D depth map.
• Flood illuminator – Provides invisible infrared light so Face ID works in the dark.
• Front-facing camera – Also part of the TrueDepth system for 2D image reference.

If any of these components fail, Face ID will stop working. And because the system is paired to the logic board, replacing individual components requires specialised calibration tools.

Face ID Problem #1: Screen Damage or Replacement

This is the most common cause of Face ID failure. The TrueDepth camera is housed in the notch (or Dynamic Island on newer models). When you crack your screen, the flex cable connecting the TrueDepth components can be damaged. If you get a screen replacement that's not done properly, Face ID can stop working.

Symptoms:

• Face ID worked before the screen cracked or was replaced.
• You see "Face ID is not available" after a screen repair.
• The screen was repaired by a shop that didn't calibrate Face ID.
• You attempted a DIY screen replacement.

What causes this:

• Damaged flex cable – The front flex cable is fragile and tears easily during screen removal.
• Dust or debris – If the TrueDepth components aren't properly cleaned and reseated, Face ID can fail.
• Missing calibration – Newer iPhones (12 and newer) require software calibration after screen replacement.
• Non-genuine parts – Cheap screens may not include the correct flex cable or may not support Face ID calibration.

How to fix it:

If Face ID stopped working after a screen replacement, it may be repairable. At iPhone Repair Nairobi, we:

• Inspect the flex cable – If it's torn, we can replace it with a pre-calibrated unit.
• Transfer the original TrueDepth components – We can move the original dot projector and flood illuminator to a new flex cable using specialised tools.
• Perform calibration – We use Apple-grade calibration tools to re-pair Face ID to your logic board.

Important: Not every repair shop can do this. Many shops will tell you Face ID is "permanently broken". We have the tools and training to restore it in many cases.

For more information, read our guide on iPhone Screen Repair vs Replacement.

Face ID Problem #2: Water or Liquid Damage

Water and Face ID don't mix. The TrueDepth camera system is sensitive to moisture, and water ingress can cause corrosion, short circuits, or fogging inside the lens.

Symptoms:

• Face ID stopped working after your iPhone got wet.
• You see moisture or fogging under the front camera.
• Other functions (like the camera) may also be affected.
• Your iPhone has a liquid damage indicator triggered.

What causes this:

• Water ingress – Even though iPhones are water-resistant, the seal degrades over time.
• Corrosion – Water leaves mineral deposits that can short-circuit the TrueDepth components.
• Condensation – Temperature changes can cause moisture to form inside the camera housing.

How to fix it:

Water damage to Face ID requires professional assessment. We can:

• Open and inspect – We'll look for corrosion on the TrueDepth flex cable and connectors.
• Clean with ultrasonic tools – Remove corrosion from the components.
• Replace damaged components – If the dot projector or flood illuminator is damaged, we can replace them.

Learn more about water damage recovery.

Face ID Problem #3: Hardware Failure

Sometimes Face ID stops working for no apparent reason. No drops, no water, no screen replacement. It just stops. This is often due to component failure – the dot projector, flood illuminator, or infrared camera may have failed.

Symptoms:

• Face ID stopped working randomly.
• You haven't dropped or damaged your iPhone.
• You see an error message saying "Face ID is not available".
• Other functions (like the front camera) may still work.

What causes this:

• Component ageing – Like any electronic component, the TrueDepth system can fail over time.
• Manufacturing defect – Rare, but possible.
• Software corruption – In some cases, the Secure Enclave may have a software issue.

How to fix it:

First, try a force restart. This can sometimes fix software-related Face ID issues.

If a force restart doesn't work, you'll need a professional diagnosis. We can test each component of the TrueDepth system and identify the failed part. Depending on the diagnosis, we may need to replace the TrueDepth module with a pre-calibrated unit.

Face ID Problem #4: Software Glitch

Sometimes the problem is in the software, not the hardware. iOS can occasionally get confused about Face ID, especially after updates.

Symptoms:

• Face ID worked before an iOS update.
• You see error messages like "Face ID is not available".
• Other functions work normally.
• Restarting the phone temporarily fixes it.

How to fix it:

1. Restart Your iPhone

A simple restart often fixes software glitches.

2. Force Restart (Hard Reset)

• iPhone 8 and newer: Press Volume Up, then Volume Down, then press and hold the Side button until the Apple logo appears.

3. Reset Face ID Settings

Go to Settings → Face ID & Passcode → Reset Face ID. Then set up Face ID again.

4. Check for iOS Updates

Go to Settings → General → Software Update and install any available updates.

If none of these work, the issue is likely hardware-related. Contact us for a diagnosis.

Face ID Problem #5: Physical Obstruction

Sometimes the problem is as simple as something blocking the TrueDepth camera. Screen protectors, cases, dirt, or even your own fingers can obstruct the sensors.

Symptoms:

• Face ID sometimes works and sometimes doesn't.
• Face ID fails but the camera works.
• You have a new case or screen protector.

How to fix it:

• Clean the front camera area – Use a soft, lint-free cloth to clean the notch/Dynamic Island area.
• Remove your screen protector – Some screen protectors don't have a cutout for the TrueDepth sensors.
• Remove your case – Some cases can block the sensors.
• Check for fingerprints – Fingerprints on the camera lens can interfere with Face ID.

Face ID on Different iPhone Models

Face ID has evolved with each iPhone generation. Here's what's different per model:

• iPhone 11 – Traditional notch. Face ID uses the same TrueDepth system as the X and XS.
• iPhone 12 – Flat-edge design. Face ID components are more compact.
• iPhone 13 – Smaller notch. TrueDepth components are more tightly packed.
• iPhone 14 – Dynamic Island on Pro models. Face ID sensors are more exposed.
• iPhone 15 – Dynamic Island on all models. Face ID is integrated into the pill.
• iPhone 16 – Camera Control button. Face ID integrated with Dynamic Island.
• iPhone 17 – Under-display Face ID on Pro models. The TrueDepth sensors are hidden beneath the display – a major change.

Each generation requires slightly different repair techniques. We stay up-to-date with the latest methods for all models.

Can Face ID Be Repaired?

Yes – but it requires specialised tools and expertise. Here's what we can do:

• Diagnose the issue – Identify whether it's the flex cable, dot projector, flood illuminator, or logic board.
• Replace the TrueDepth module – We use pre-calibrated units that maintain the cryptographic pairing.
• Transfer original components – We can move your original dot projector and flood illuminator to a new flex cable.
• Calibrate Face ID – We use Apple-grade tools to ensure Face ID works perfectly after repair.

Success rate: In most cases (especially with screen damage), we can restore Face ID. In cases of severe water damage or logic board failure, the success rate is lower – but we'll be honest with you about your options.

Face ID repair starts from KSh 4,500 for most models. The exact cost depends on your iPhone model and the specific issue.

Frequently Asked Questions

Can Face ID be fixed after a screen replacement?

Yes – in many cases. If the screen repair was done without proper calibration, we can often restore Face ID by transferring the original TrueDepth components or replacing the flex cable.

Does water damage affect Face ID?

Yes. Water can cause corrosion, fogging, or short circuits in the TrueDepth system. If your iPhone has been exposed to water, follow our water damage guide.

How much does Face ID repair cost in Nairobi?

Face ID repair starts from KSh 4,500 for most models. The exact cost depends on your model and the specific issue. Contact us for a quote.

Can Face ID be disabled permanently?

Face ID can be permanently disabled if the TrueDepth system is severely damaged or if the Secure Enclave is corrupted. However, in most cases, it can be repaired or replaced.

What is under-display Face ID?

Under-display Face ID is available on the iPhone 17 Pro and Pro Max. The TrueDepth sensors are hidden beneath the display, eliminating the notch or Dynamic Island. This makes repairs more complex – but we have the tools to handle it.

Will resetting my iPhone fix Face ID?

A software reset (like Reset All Settings) or a force restart can fix software-related Face ID issues. However, if the problem is hardware, resetting won't help – you'll need professional repair.

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