The proximity sensor in Xiaomi Redmi smartphones is a small but critical element that is responsible for turning off the screen during a phone conversation. When you bring the device to your ear, the sensor registers the obstacle and extinguishes the backlight, preventing accidental pressing. If the sensor starts to fail, this leads to unpleasant consequences: the screen does not turn off when you call (and you press the buttons with your cheek), or vice versa, it goes out for no reason, blocking access to the interface.
Proximity sensor problems are often confused with display or firmware malfunctions. For example, Redmi Note 10 Pro or POCO X3 Pro users complain of “spontaneously turning off the screen” without even knowing that the sensor is to blame. In this article, we will discuss 5 reliable ways to check — from simple tests through the engineering menu to visual inspection of the board. You will learn how to distinguish a software failure from a physical failure, and what to do if the sensor does not respond at all.
Important: on new Xiaomi models (like the Redmi 12 or POCO F5), the proximity sensor is often integrated into the speaker or front camera, which complicates diagnosis, but does not make it impossible.
1. Quick check through a phone call
The easiest way to detect a malfunction is to simulate a phone conversation, which doesn't require app installation or code entry, but it gives you a clear idea if the sensor is working at least at a basic level.
Take a second phone (or ask a friend) and call your Redmi.
- 📞 Hold the smartphone to your ear – the screen should go out instantly (usually within 0.5-1 seconds).
- 🖥️ Take the device away from the face – the display should immediately turn back on.
- 🔄 Repeat the motion 3-4 times, changing the angle of inclination.
If the screen does not go out at all, the sensor is faulty or disabled in the settings. If it goes out but with a delay (more than 2 seconds), the problem can be a problem in the sensor contamination or damage to the plume. On Redmi 9A models and older, a delay of more than 1 second is already considered a deviation.
⚠️ Attention: On some firmware MIUI (especially custom) the function of turning off the screen during the call can be manually disabled. Before checking, make sure that the Settings → System applications → Phone. → Turn off the screen during the call is worth a checkmark.
2. Testing through the engineering menu (codes ##)
The engineering menu is a hidden tool Xiaomi, which allows you to check hardware components, including the proximity sensor. USSD-The method works on most Redmi models (from Redmi). 4X Up to Redmi Note 13 Pro+), It may not be available on some custom firmware.
Enter the following code in the Phone application:
##6484##Then the Manual Test menu will open, or the Hardware Test on newer versions of MIUI, and find the Proximity Sensor and tap it. The screen should turn black, that's OK. Now do the check.
- 🖐️ Close the sensor with your hand (or bring an opaque object to it).
- 📱 The screen should have Near or 0 cm (values vary).
- 🙌 Remove your hand – the inscription should be changed to Far or 5 cm (maximum response distance).
If the values do not change or if the Fail error is displayed, the sensor is defective. On some models (for example, the POCO F3), instead of numbers, a graph may be shown, the green line should rise sharply when the hand is approached.
3. Verification with third-party applications
If the engineering menu is unavailable or the data seems unreliable, use specialized applications, which not only test the sensor, but also show its technical parameters: response time, sensitivity, possible artifacts.
The best applications for Xiaomi Redmi:
- 📱 Phone Doctor Plus checks all sensors, including proximity, light and accelerometer.
- 🔍 Sensor Box for Android – displays the sensor’s graph in real time, useful for detecting floating malfunctions.
- 🛠️ CPU-Z — Sensors shows the status of the proximity sensor (if it is recognized by the system).
How to test in Sensor Box:
- Install the app from Google Play.
- Open the Proximity tab.
- Put your finger on the sensor (usually to the right of the speaker) and the graph should change dramatically from Far to Near.
- Repeat the test 5-7 times. If the graph "shaking" or is triggered with a delay, the sensor needs to be cleaned or replaced.
⚠️ Attention: Redmi with AMOLED-screens (e.g. Redmi) K50) The proximity sensor may be falsely triggered by the infrared radiation of the display, in which case try testing in a dark room.
Make sure there is no protective film or glass on the screen
Disconnect power saving modes
Close all background applications
Check that the sensor is not covered with a cover-->
Visual inspection of the sensor and the speaker
If software tests show a malfunction, inspect the sensor physically. On most Redmis, it is located at the top of the screen, to the right of the front camera or speaker. Externally, it is a small circular hole (sometimes closed with a grid) or a transparent window under the glass.
What to look for when inspecting:
- 🧹 Pollution: Dust, leakage from cosmetics or moisture can block the infrared signal. Gently wipe the area with a soft brush or cotton swab dipped in alcohol.
- 🔧 Damage: Cracks on the glass above the sensor, dents or glue marks (for example, after replacing the display).
- 📦 Cover or film: Tight ear covers or poor-quality protective glass can overlap the sensor.
On Redmi Note 8 Pros and similar models, the proximity sensor is often combined with a light sensor, and if both sensors are not working, the problem may be in the plume or the motherboard.
| Xiaomi Redmi Model | Location of the sensor | Typical malfunctions |
|---|---|---|
| Redmi 9/9A/9C | Right of the speaker, under the grid. | Dust pollution, plume detachment |
| Redmi Note 10/11 Pro | Under the glass, next to the front camera. | Moisture intrusion, damage when replacing the screen |
| POCO X3/X4 | In the camera notch (integrated) | False positives due to IR interference from AMOLED |
| Redmi 12/13 | Hidden under the display (without an external hole) | Failures after MIUI update |
What does the proximity sensor look like on different models
5. Checking the plume and contacts (for experienced users)
If the sensor doesn't respond to the tests but looks good, the problem may lie in the plume connecting it to the motherboard, a method that requires disassembling the phone and is only suitable for those with experience with electronics.
What you need:
- 🔧 Set of screwdrivers (star) T3, T4).
- 🧲 Plastic blade for opening the body.
- 🔍 Loupe or magnifying glass.
- 📸 Camera (to capture the location of the plumes).
Step-by-step:
- Turn off the phone and remove it. SIM-map.
- Carefully tuck the back cover (start at the corner near the power button). A metal-bodyed Redmi (Note 5 and older) will require a hair dryer to soften the adhesive.
- Unplug the battery (required!), then find the proximity sensor plume, which usually goes from the top of the board to the speaker.
- Check the contacts on the plume and the connector of the board: whether there is oxidation, contamination or mechanical damage.
- If the plume is moving away - gently connect it back and fix it with tape.
On the Redmi Note 9 Pro and similar models, the proximity sensor plume is often combined with the front camera plume, and when it is damaged, both the camera and the sensor may not work.
⚠️ Note: If you've never disassembled smartphones, it's best to contact the service. IP53 (For example, Redmi 10) with careless disassembly, you can damage the waterproof gaskets, which will lead to loss of tightness.
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Before disassembling, take a picture of the location of all the plumes and screws. Xiaomi often uses screws of different lengths - confusing them, you can damage the board.
6.Diagnostics via ADB (for advanced users)
If standard methods fail, check the sensor through Android Debug Bridge (ADB), which requires a computer and basic command line knowledge, but provides the most accurate data.
What needs to be done:
- Turn on USB Debugging in Settings → About Phone → MIUI version (tap 7 times on version number, then go back to Additional → For Developers).
- Connect Redmi to your PC and open the terminal (or Command Prompt on Windows).
- Enter the command to check the sensors: adb shell dumpsys sensorservice In the conclusion, find the Proximity Sensor block - there will be data on its status and recent readings.
- For the real-time test, use: adb shell getevent -l Close the sensor with your hand - events should appear in the log ABS_DISTANCE=0 (near ABS_DISTANCE=1 (farther).
If there is no mention of the proximity sensor in the log, this means:
- 🔌 Sensor is physically disabled (problem with plume or board).
- 🔄 The sensor driver is not loaded (flashing will help).
- 🚫 The sensor is not available in principle (on some budget models, for example, Redmi). A1, he may not be).
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If ADB does not see the proximity sensor, and the engineering menu shows an error, there is a 90% probability that the problem is hardware (a sensor or plume is damaged).
Frequent causes of proximity sensor failure
The proximity sensor on Xiaomi Redmi fails for a few typical reasons, and knowing them can prevent a breakdown or quickly eliminate its consequences.
The main culprits are:
- 💧 Moisture: Water (even in small amounts) oxidizes the sensor contacts. IP53 (For example, Redmi 10) protection is weak - enough splash or high humidity.
- 📱 Fall or impact: Even if the screen is intact, microcracks on the board or the detachment of the plume can disrupt the sensor.
- 🔧 Poor repair: After replacing the display or battery, the master sometimes forgets to connect the sensor plume.
- 🔄 Firmware update: On MIUI 13/14 There were bugs that caused the sensor to stop working after the update, so it can be done by rolling back or resetting the settings.
- 🧴 Cosmetics and creams: Fat deposits from creams or tonal products clog the sensor, especially on models with an open hole (Redmi). 7/8).
On the POCO M3/M4 and other budget models, the proximity sensor often fails due to overheating. If the phone gets too hot during games, check its temperature in the AIDA64 app - at values above 60 ° C, the sensor can malfunction.