Introduction: why you need a sensor approach in a smartphone
The proximity sensor is a small but critical component of modern smartphones, including the Xiaomi Redmi Note 8 Pro. Its main task is to detect when you bring the device to your ear while you call. Without this sensor, the screen would not turn off when you talk, which would lead to accidental clicks of the cheek or ear on touch buttons. But where exactly is it hidden in the case of the Redmi Note 8 Pro, and how to know if it is not working correctly?
Many users don’t even know it exists until they encounter problems: the screen doesn’t go out during a call, buttons are accidentally pressed, or the display doesn’t turn on after a conversation is over. In this article, we’ll look at where the proximity sensor in the Redmi Note 8 Pro is physically located, how it works, and what to do if it stops functioning correctly.
Where is the proximity sensor in the Redmi Note 8 Pro: the exact location
In the Xiaomi Redmi Note 8 Pro, the proximity sensor is integrated into the top of the screen, next to the front camera and speaker, specifically, it is located under the display glass, to the left of the selfie camera, if you look at the phone in the standard position (the speaker on top), visually it is not visible, because it is hidden under an opaque layer of glass, but its position can be determined by a small hole or area with a different reflectance of light.
To get a better idea of where to look, look at the top of the screen: the front camera on the right, the conversational speaker on the center, and the proximity and illumination sensor on the left (they are often combined into one module).
If you look closely, you can notice a barely noticeable point or a small indentation - this is the location of the sensor.
- 📱 Visual landmark: left of the camera, under glass (not to be confused with the infrared port, which is missing in this model).
- 🔍 How to check: Hold your phone to a bright light source at an angle - the sensor may differ slightly in texture.
- ⚠️ Warning: Do not try to peel off the glass or penetrate into it - this will lead to loss of leakage!
How the approximation sensor works: the principle of operation
The proximity sensor in the Redmi Note 8 Pro uses infrared (IR) operation, and it consists of two key elements: the emitter (sends an invisible infrared signal) and the receiver (catches the reflected signal).
When you hold the phone to your ear, the infrared beam bounces off the surface and comes back, and the system analyzes the time and intensity of the reflection, determining the distance to the object.
The algorithm of the work is simple:
1.During the call, the sensor is activated and begins to scan the space in front of the screen.
2 If the distance to an object (e.g. your ear) is less than 5-10 mm, the system locks the screen and disables touch taps.
3.As soon as you pull the phone away, the sensor detects the absence of an obstacle and unlocks the display.
⚠️ Attention: The proximity sensor can falsely fire if it has accumulated dirt, dust or moisture, and is also disrupted by using thick protective glasses with opaque areas at the top.
| Parameter | The value of the Redmi Note 8 Pro |
|---|---|
| Type of sensor | Infrared (IR) |
| Response range | 0-10 mm |
| Location. | Under glass, to the left of the front camera |
| Sensitivity | Adjusted programmatically (in settings) |
How to check the operation of the proximity sensor: step-by-step instructions
If you suspect that the proximity sensor in your Redmi Note 8 Pro is not working properly, you can test it without special tools.
Method 1: Test through the engineering menu (code ##6484##)
- Open the Phone app and enter the combination: ##6484##.
- Select Proximity Sensor (Proximity Sensor).
- Raise your hand to the top of the screen – the value should change from 5.00 (no obstacle) to 0.00 (there is an obstacle).
- If the values do not change or show an error, the sensor is defective.
Method 2: Checking through the application
Install any sensor testing app from Google Play, such as Sensor Test or Phone Doctor Plus. Run a proximity sensor check and repeat the test as your hand approaches. The app will show if the sensor detects changes.
Make sure there is no dirt or protective film on the screen at the top |
Close all background applications |
Use the original charger (if the test is done when you connect to the network)|
Repeat the test 2-3 times for accuracy-->
Typical problems with the proximity sensor and their causes
Redmi Note 8 Pro users are most often faced with the following proximity sensor malfunctions:
- 📵 The screen does not go out during the call - the sensor does not detect the approach of the ear, or its signal is blocked by a protective glass or cover.
- 🔄 The screen does not turn on after the call - the sensor "whilts" and continues to believe that the phone is pressed to the ear.
- ⚡ Spontaneous triggers – the sensor responds to foreign objects (such as hair, clothing) or works with a delay.
- 🛠️ Complete inoperability – the sensor does not respond to any actions, in tests shows an error.
The causes of the problems can be divided into two categories:
- Software: Failure in the firmware after the MIUI update; conflict with installed applications (especially those that change the call interface); incorrect sensitivity settings (less often, but occurs).
Hardware:
- Damage to the sensor after a fall or impact.
- Getting moisture under the glass (even without full flooding).
- Wear or detachment of the plume connecting the sensor to the motherboard.
What if the sensor doesn’t work after a fall?
How to fix the malfunction of the proximity sensor: from simple to complex
Before carrying your phone for repair, try the following steps:
1. Cleaning the top of the screen
Accumulation of dust or fat on glass in the sensor area can block the IR signal. Wipe the top of the screen with a soft lilac-free wipe soaked in alcohol. Avoid aggressive cleaning products!
2. Reset sensor settings
Sometimes it helps to reset the calibration of sensors through the engineering menu:
1. Enter the code ##6484##.
2. Select Proximity Sensor.
3. Press Calibrate (if available).
4. Reboot the phone.
3. Update or roll back firmware
If the problem has occurred after the MIUI update, try:
- Update to the latest stable version of the firmware.
- Reverse to the previous version (if you know that the sensor worked before).
⚠️ Attention: Firmware rollback may cause data loss.Pre-backup through Settings → Additionally. → Backup and reset.
4. Checking for application conflict
Some applications (e.g., alternative calls or launchers) may interfere with the sensor. Launch the phone in Safe Mode (press the power button → Safe Mode) and check if the problem persists. If the sensor is working properly, uninstall the recently installed programs.
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If the sensor is too sensitive (e.g., it reacts to hair), try to reduce its sensitivity through the engineering menu. Type ##36446337##, find the Proximity Sensor section and reduce the Threshold parameter by 1-2 units.
When you can not do without repair: signs of hardware breakdown
If none of the software methods worked, the problem is likely in the sensor itself or its connection.
- 🔧 Physical damage: cracks in the glass at the top of the screen, traces of moisture under the display.
- 📉 Persistent errors in tests: the sensor does not respond to any actions, in the engineering menu shows N/A error.
- 🔄 Unstable after heating: the sensor works normally when the phone is cold but "gluts" after loading (e.g., games.
- 🛠️ Problems after disassembly: if the phone was previously repaired (for example, the display was changed), the sensor plume could be damaged.
The cost of repairing the proximity sensor in the Redmi Note 8 Pro depends on the reason:
- Replacement of the sensor (if it is separate) - from 800-1500 ₽.
- Replacement of the plume - from 1500-2500 ₽.
- Replacement of the display module (if the sensor is soldered into the screen) – from 4000-6000 ₽.
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If the proximity sensor in your Redmi Note 8 Pro stopped working after falling or getting moisture, don't delay repairs.Prolonged use with a faulty sensor can lead to accidental taps during calls (for example, turning off the microphone or completing a call).