Approximation Sensor in Xiaomi 13T: device, diagnosis and problem solving

The Xiaomi 13T is a flagship smartphone with advanced hardware, but even such devices are not immune to failure. One of the common problems that users face is the incorrect operation of the proximity sensor. This small but important component is responsible for turning off the screen during a phone conversation, preventing accidental tapping of the cheek or ear. If the sensor fails, this leads to discomfort: the screen does not go out, touch buttons are activated arbitrarily, and the battery discharges faster.

In this article, we will discuss which proximity sensor is installed in the Xiaomi 13T, where it is physically located, how to check its performance and what to do if it ceases to function, and you will learn about software and hardware diagnostic methods, as well as whether it is possible to replace the sensor yourself, the material will be useful for both beginners and those who have already experienced similar malfunctions.

What is the proximity sensor used in the Xiaomi 13T?

Xiaomi. 13T infrared sensor of approach (IR proximity sensor, which is based on the emission and reception of the reflected signal, and unlike older capacitive sensors, infrared sensors are more accurate and less prone to false positives. Specifically, this model uses a module from STMicroelectronics, one of the leading manufacturers of sensors for mobile devices.

The sensor is integrated into the top of the display, next to the front camera and the speaker, and it's a pair of elements: an IR emitter (sends an invisible light signal) and an IR receiver (reflects the signal), and when you hold the phone to your ear, the signal bounces off the surface and comes back, which is the command to turn off the screen.

• 🔹 Type of sensor: Infrared (IR)
• 📱 Manufacturer: STMicroelectronics (according to the disassembly data)
• 📏 Location: Top screen frame, right of front camera
• ⚡ Power: Connected to the main board via a flexible display plume

Importantly, the Xiaomi 13T pairs the proximity sensor with the light sensor in one module, a typical solution for modern smartphones that saves space and simplifies design, but this combination means that if one of the sensors fails, the entire module may need to be replaced.

Where is the proximity sensor in Xiaomi 13T?

Physically, the proximity sensor in the Xiaomi 13T is located at the top of the smartphone, under the display. If you look at the front panel of the device, it is located to the right of the front camera, next to the speaker for conversations. Visually, it is not visible, because it is hidden under the glass of the screen, but its position can be determined by a small hole in the frame (if you look at the angle).

To get a better idea of where to look for a sensor, imagine the top of the screen as a conventional line with three elements left to right:

1. Front camera (center or left, depending on orientation)
2. Light/approximation sensor (right of camera)
3. Speaker for conversations (far right element)

If you take your phone apart (for example, to replace the screen or clean), the proximity sensor is attached to the flexible plume of the display and connected to the main board through a connector, and if you do not handle the plume carefully, the plume can be damaged, which will lead to the sensor inoperability.

How does the proximity sensor work in Xiaomi 13T?

The approach sensor in the Xiaomi 13T is based on infrared radiation, and when you hold your phone to your ear during a call, what happens is:

1. Sensor activation: When a call is started, the system automatically turns on the IR emitter, which starts sending invisible light pulses.
2. Signal reflection: When the phone approaches a surface (such as an ear or shoulder), the IR ray is reflected and returned back.
3. Receiver Fixing: The IR receiver picks up the reflected signal and sends the data to the processor.
4. Screen Disconnection: The system interprets the signal as a command and turns off the display, as well as blocking touch taps.

If the sensor is working correctly, the screen should go out within 0.5-1 seconds of the phone approaching the ear. When the phone moves away (for example, when you end a conversation), the sensor detects the absence of a reflected signal and turns the display back on.

In Xiaomi 13T, a dedicated controller built into the motherboard is responsible for processing the sensor signals, and it analyzes the data and sends commands to the operating system. If at some point a failure occurs (for example, the sensor is contaminated or the plume is damaged), the screen may not go out or, conversely, it may turn off arbitrarily.

How to check the proximity sensor on Xiaomi 13T?

If you suspect that the proximity sensor in your Xiaomi 13T is not working properly, you can test it in a number of ways, starting with the simplest, the visual test:

1. Open the Phone app and dial the number (no need to make a real call – simulation is enough).
2. Hold your hand or any opaque object (such as a book) to the top of the screen where the sensor is located.
3. If the screen goes out, the sensor is working, and if it's not, move on to the next step.

If the visual test did not give results, use the hidden engineering menu or specialized applications.

Method 1: Engineering Menu (CIT)

The Xiaomi 13T has a built-in engineering menu where you can check the status of the sensor:

1. Open the Phone app.
2. Enter the code: ##6484## (or #4636## → Equipment Testing).
3. Select Proximity Sensor (Proximity Sensor).
4. Put your hand in the sensor, the value should change from 5 (no obstacle) to 0 (there is an obstacle).

Method 2: Diagnostic applications

If the engineering menu is not available, install one of the sensor testing apps:

• 📱 CPU-Z (sensors)
• 🔧 Phone Doctor Plus (Test of Sensors)
• 🛠️ Sensor Test (specialized tool)

These programs will show the current values of the proximity sensor in real time, and if the value does not change when you approach the hand, the sensor is defective.

Put your hand to the top of the screen during the call.|Check the screen reaction (must go out)|Start the Engineering Menu (#6484##)|Install an application for sensor diagnostics|Clean the sensor of dirt (if there is suspicion of contamination)-->

Why does the proximity sensor in the Xiaomi 13T not work?

If the proximity sensor in your Xiaomi 13T has stopped functioning, the reasons may be both software and hardware.

• 📱 Software failure: Application conflict, firmware error or resetting can cause the sensor to malfunction. Often the problem is solved by rebooting or resetting to factory settings.
• 🔌 Train damage: Falling or disassembling the phone could damage the flexible plume connecting the sensor to the motherboard, requiring a replacement plume.
• 💦 Moisture: If the phone was in contact with water, the sensor or its contacts could oxidize. This is one of the most difficult malfunctions, as it requires professional cleaning.
• 🧹 Sensor pollution: Dust, dirt, or protective film can block the IR signal, in which case it is enough to clean the surface carefully.
• 🔧 Controller malfunction: Rarely, but it happens that the chip responsible for processing signals from the sensor fails.

Important: 80% of the time, the proximity sensor malfunction in the Xiaomi 13T is due to contamination or software failure, not physical failure, so you should try self-diagnosis and cleaning before visiting the service center.

⚠️ Warning: If the sensor stopped working after the phone fell or moisture hit, do not try to disassemble the device yourself! In this case, there is a high probability of damage to other components.

How to fix the proximity sensor in Xiaomi 13T?

If the proximity sensor in your Xiaomi 13T doesn’t work, try the recovery software first.They don’t require disassembling the phone and in most cases help troubleshoot the problem.

Step 1: Reboot your phone

Sometimes the sensor can freeze due to a temporary failure in the system.

1. Press the power button for 10-15 seconds.
2. Select Reboot.
3. After turning on, check the sensor.

Step 2: Clean the sensor

If dirt or dust has accumulated on the surface of the sensor, it can be cleaned carefully:

• Take a soft lilaless fabric (for example, for glasses).
• Slightly moisten it with alcohol solution (no more than 70%).
• Wipe the top of the screen in the sensor area (don’t press hard!).
• Let the phone dry for 5-10 minutes.

Step 3: Resetting settings

If the problem is caused by an application conflict or a firmware failure, resetting to factory settings will help:

1. Go to Settings → About the phone → Reset settings.
2. Select Reset all settings (does not delete files) or Delete all data (complete reset).
3. Confirm the action and wait for the process to be completed.

⚠️ Warning: If the sensor doesn't work after resetting, and it doesn't show changes when the hand is approaching on the engineering menu, it's a hardware problem, and you'll need to replace the sensor or the plume at the service center.

If you're confident in your skills, you can try replacing the sensor yourself, but you'll need to:

• 🛠️ Special set of screwdrivers for Xiaomi.
• 🔥 Hair dryer for softening glue (when changing the screen).
• 📱 New proximity sensor (can be ordered on AliExpress or in specialized stores).

The cost of replacing the sensor in the service center is 1,500-3,000 rubles, depending on the region and the complexity of the work.

💡

If the proximity sensor started to fail after updating the firmware, try to roll back to the previous version of MIUI. To do this, download the necessary firmware from the official Xiaomi website and run your phone through Fastboot or Recovery.

Frequent questions about the proximity sensor in Xiaomi 13T

💡

If the proximity sensor in Xiaomi 13T stopped working, first check it through the engineering menu or diagnostic applications. 80% of the time the problem is solved by cleaning the sensor or resetting the settings.