Troubleshooting Face ID Issues on Your iPhone - CHINA PHONEFIX
If you're experiencing issues with Face ID on your iPhone and wondering how to fix them, you've come to the right place. This PHONEFIX guide will help you understand how Face ID and the TrueDepth camera system work and provide solutions to common Face ID problems.

Understanding Face ID and the TrueDepth Camera System

Face ID relies on several key components within your iPhone's TrueDepth camera system:
1. Flood Illuminator
The Flood Illuminator is a small laser that acts as the "porch light" of the Face ID system.

2. Dot Projector
The Dot Projector uses a prism to project an array of infrared dots onto your face.

3. TrueDepth Cameras
The TrueDepth Cameras include the front-facing (selfie) camera and an infrared (IR) camera, which work together for depth perception.
Please note that these components are cryptographically tied to your device's CPU, meaning they cannot be easily replaced without involvement from the manufacturer.

Common Face ID Problems and Solutions

1. Flood Illuminator Problems

The most frequent cause of Face ID malfunction is issues with the Flood Illuminator located on the top side, specifically on the screen. Some common problems include:

  • Water damage: Even a small amount of water, such as a drop from a cleaning wipe or sweat, can corrode the Flood Illuminator if it enters through the ear speaker mesh.
  • Torn front flex: During a screen replacement, the thin black flex connecting the Flood Illuminator to the logic board may accidentally tear, preventing the porch light of the Face ID system from turning on.
When Face ID fails due to Flood Illuminator problems, you may receive a notification saying "Unable to activate Face ID" or encounter an error message when trying to enable Face ID in the settings.
Fortunately, these issues can often be resolved. If the Flood Illuminator itself is undamaged, it can be desoldered from its original flex, cleaned, and resoldered onto a known good flex from another phone. This procedure restores Face ID functionality lost due to water damage or torn flex accidents.

2. Dot Projector Problems

The good news is that the most common Face ID problem on the bottom side of the clamshell is a failed Dot Projector. The Dot Projector is a small glass-like square adjacent to the TrueDepth cameras and contains an internal fuse that can easily be damaged. This can occur through water exposure or even by accidentally touching it.
To determine if the Dot Projector is the issue, you can use a QianLi iCopy Plus 2.2 Programmer. If the reader indicates a faulty Dot Projector, the next step is to replace it.

This process requires specialized equipment, including removing the Dot Projector, soldering it onto a new receiver QianLi Dot Matrix Flex, performing a read/write operation to transfer the serial number, and delicately epoxying the prism in place.

In the majority of cases, this restores Face ID functionality, except for severe damage to the front/selfie or IR cameras.
Here is the Face ID Troubleshooting Flowchart


In summary, this article provided an overview of Face ID on iPhones, explained common issues affecting Face ID, and offered repair solutions. PHONEFIX offers all repair tools, such as the QianLi iCopy Plus 2.2 Programmer and the Face ID Reballing Stencil and Qianli Dot Projector Fixture, for Face ID repairs.
These tools, along with professional repair services or guidance, can help diagnose and resolve Face ID problems effectively.
Face idRepair guide

Leave a comment

All comments are moderated before being published