Owners of Xiaomi Redmi 8 Pro smartphones often face a situation where the screen goes out during a conversation or, conversely, does not respond to the device’s presentation to the ear. The root of the problem lies in the incorrect operation of the sensor responsible for determining the proximity of objects. Understanding the exact location of this element is critical for proper diagnosis and solving technical difficulties.
Unlike older models, where the sensor was placed under the top speaker, in modern devices it is integrated into the overall design of the display module. On the Redmi 8 Pro, this component is hidden under the protective glass, making it invisible to the naked eye, but equally important for comfortable use of the gadget.
In this article, we will discuss in detail where the proximity sensor is located, how it interacts with the system and what to do if its operation is disrupted. You will learn about software methods of setting up and physical ways to eliminate interference that can block the signal.
Design features of the sensor location
The Proximity Sensor technology in the Xiaomi Redmi 8 Pro is based on infrared radiation. The sensor emits an invisible beam and analyzes the reflected signal. If the object is close, the screen locks, and in this model, the manufacturer abandoned the remote sensor in favor of an integrated solution placed directly under the display panel.
The physical active area is located at the top of the screen, usually in the center or with a slight shift towards the speaker. The exact location is hidden by a black frame or directly under the matrix in the top third. The user cannot see it visually, because it is closed with a layer of glass and touchscreen. This engineering solution allows you to keep the housing tight and protect the electronics from dust.
It’s worth noting that the Redmi 8 Pro uses a combined approach where the light sensor and proximity sensor can be combined into one module or be in close proximity to each other, creating a single sensitive area at the top of the screen. Any film not designed for specific Xiaomi models with this design can overlap the work sector.
⚠️ Warning: Never try to disassemble a display module to "clean" the sensor unless you have professional equipment.A leakage will cause dust to enter the glass, which will permanently disable the screen.
Understanding that the sensor is part of a complex multilayer structure helps avoid maintenance errors. Attempting to wipe the screen at a particular point with aggressive chemicals can damage the oleophobic coating, but will not improve the sensor's performance if the problem lies in a software failure or factory failure of the plume.
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Use only a soft microfiber to wipe the top of the screen. The fuzzy tissues can leave particles that the system mistakenly perceives as an object approaching.
Why the sensor may not work properly
Failures in the proximity sensor on Xiaomi Redmi 8 Pro is a common phenomenon with several causes, most often the problem is software-related or external factors, the system may misinterpret the data if the calibration went wrong after updating the firmware or replacing the display.
Physical obstacles are the second most popular cause. Security windows with black frames that don't match the factory's often block the infrared beam. Even a microscopic crack at the top of the screen or a greasy film from the fingers can distort readings. Dirt accumulated in the speaker grid also blocks access to the sensor.
List of main causes of malfunctions:
- 📱 Incorrectly selected protective glass or film covering the work area.
- 💻 Software failure after operating system update MIUI.
- 🔧 Unqualified replacement of the display without subsequent calibration.
- 🧼 Pollution of the top of the screen with fat or dust.
In some cases, the culprit is the case itself, and if the accessory's sides are too high and overhanging the screen, they can get into the sensitivity zone, which makes the phone think it's in your pocket or in your ear, and lock the display at the wrong time. Checking the operation without the cover is the first step of diagnosis.
Diagnosis and testing of performance
Before you can carry the device for repair, you need to do a self-diagnosis, and the MIUI has a powerful engineering menu built in to test all the hardware components, which will eliminate the possibility of software glitches and accurately indicate a physical malfunction.
To run the test, use a special code in the Phone app. Dial the combination ##6484##. The CIT menu will open. In the test list, look for the Proximity Sensor or Approximation Sensor. When you click on it, you will see a graph or numerical values that change when you hold your hand to the top of the screen.
The testing process is as follows:
- Run the engineering menu through the code.
- Select the proximity sensor test.
- Close the top of the screen with your palm.
- Remove your hand and watch the change in values.
If the values do not change or change randomly, the problem is confirmed. In the normal state, when the sensor is closed, the value should change dramatically (for example, from 0 to 5 or from Far to Near). If there is a reaction, but the system malfunctions, then software calibration is required. The absence of a reaction indicates physical damage to the plume or the module itself.
⚠️ Note: Do not use magnets or metal objects in tests, and the Hall sensor and the proximity sensor can respond to a magnetic field, giving a false positive result.
Hidden codes for diagnosis
Software calibration of the sensor
If testing shows that the sensor is responding but is not responding correctly (the screen goes out too soon or later), calibration is required.This procedure "trains" the system to correctly determine the threshold values of distance. On the Xiaomi Redmi 8 Pro, this can be done through an engineering menu or special applications.
Standard method through CIT-The menu will select the calibration point, and you'll be asked to remove your hand from the screen and then close it. After you do the actions, press the confirmation button. The system will record the new reference values. It's important to do this in good lighting and with a clean screen surface.
The alternative is to use the Proximity Sensor Reset & Fix app or Google Play analogues, which have access to hidden Android settings.
- 📲 Install the calibration application.
- 🖐️ Follow the instructions on the screen (close and open the sensor).
- 💾 Save new settings and restart the device.
After calibration, make sure to reboot the smartphone completely, so that the new parameters are written into the permanent memory and take effect. If after calibration and reboot the problem persists, it is likely to be the hardware.
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Calibration is a software-based sensitivity setting that can't fix a physical plume break or a broken sensor, but it solves 90 percent of software problems.
Physical methods of troubleshooting
When software is powerless, you have to go to physical harm. On the Redmi 8 Pro, a common cause is the plume being displaced or oxidized. If you have the skills to repair, you can gently open the device and check if the plume is connected to the motherboard.
Often, simple cleaning of the top of the body helps. Use a soft brush and isopropyl alcohol (in minimal amounts) to clean the speaker mesh and the area around it. Dirt mixed with sweat and skin fat forms a conductive layer that distorts the sensor. Careful cleaning can do wonders.
Table of common problems and solutions:
| Symptoms. | Probable cause | Method of decision |
|---|---|---|
| The screen doesn't go out when you talk. | Calibration failure | Program calibration through CIT |
| The screen goes out in your pocket | Dirt or cover | Cleaning, cover removal. |
| Sensor fails to respond in tests | The plume break | Replacement of display or soldering |
| Screen flickering in the ear | Bad contact. | Reconnecting the plume |
As a last resort, if the sensor is physically defective, you can use a software emulator. There are applications that use a gyroscope and an accelerometer to simulate the sensor's operation. For example, if the phone is held vertically and close to the head, the software will force the screen to go out, which is a temporary solution, but it allows you to use the device comfortably before repair.
☑️ Checklist before going to the service
Impact of protective accessories and updates
Don't underestimate the impact of accessories on the electronics of a smartphone. Since the Redmi 8 Pro came out, many protective glasses. Cheap counterparts often have misaligned cutouts or a black frame that physically closes the sensor. Even if visually everything matches, the thickness of the glass can be too large for an IR beam.
MIUI updates also make adjustments, sometimes resetting factory calibration data after an update, in which case recalibration through the engineering menu is mandatory, and developers can change the algorithms of the sensor, making it more or less sensitive depending on the version of the firmware.
It is recommended to use original accessories or proven brands that guarantee compatibility with a particular model. If after sticking a new glass, you start to get problems, remove it and check without it. This is the fastest way to identify the culprit.
⚠️ Attention: Using cheap chargers can cause electrical interference that affects the touchscreen and sensors.If problems started after the charge change, try the original unit.
Remember, the Xiaomi Redmi 8 Pro is a complex device where all components are interconnected. The proximity sensor, though small, plays a key role in ergonomics. Regular screen cleaning, neat handling and timely calibration will prolong the life of your gadget and save nerves.