The situation when the smartphone screen Xiaomi or Redmi continues to light up during a telephone conversation, is one of the most common user complaints. This is not just an annoying little thing that irritates the eye with a bright light in the dark. A constantly active display leads to the fact that you randomly press your cheek on the buttons, hang up a call, turn on the speakerphone, or open applications directly during a dialogue.
The root of the problem lies in work proximity sensor. This compact module is required to turn off the backlight and the touch layer as soon as an object (your ear) is in close proximity to the top of the case. If this does not happen, it means that the signal transmission chain from the sensor to the processor and then to the screen control system is interrupted somewhere.
Owners of devices based on MIUI and the new shell HyperOS face this more often due to the specific location of the sensors under the display glass in modern models. Below we will analyze in detail the mechanical, software and physical causes of the failure, and also provide step-by-step guide for troubleshooting without contacting a service center.
Mechanical obstacles and protective accessories
The most commonplace, but at the same time the most common reason for the sensor to not work correctly is a physical barrier. In older smartphone models, the sensor was located in a separate cutout above the screen, and it was difficult to close it. However, modern Redmi Note and flagship series use the technology of placing the sensor directly under the display matrix or in a narrow frame, which is easy to cover.
Poor quality protective glass or incorrectly pasted film may have a darkened area or simply a thick layer of glue in the area where the sensor operates. Even a microscopic air bubble or a layer of dust that has accumulated under the edge of the glass over six months of operation is capable of scattering the infrared beam that the sensor emits to detect obstacles.
It is also worth paying attention to the design of the case. Some protective bumpers with high sides or a solid front panel (so-called "window books" or one-piece 360-degree cases) may block the top of the screen. If the case has tinted glass in the speaker area, the system may perceive it as a permanent obstacle or, conversely, not see the ear actually approaching due to signal distortion.
- 🧼 Gently wipe the top of the screen with an alcohol wipe, paying particular attention to the area above the speaker where the sensor is hidden.
- 📱 Try temporarily removing the protective glass to see if the behavior changes screen during a call.
- 🛡️ Make sure that your case does not have protruding elements or darkening in the upper third of the display.
⚠️ Attention: If you recently changed the screen in an unofficial service, the problem may be in the quality of the spare part. Cheap copies of displays often have incorrectly positioned components or lack of calibration of the proximity sensor at the factory.
Before purchasing a new protective glass, search the Internet for reviews specifically for your Redmi model. Some glass manufacturers specifically make a cutout for the sensor, which guarantees its correct operation.
Software failure and operation in safe mode
Sometimes the hardware is fine, but the software does not process sensor data correctly. In the ecosystem, the Phone system application and background process services are responsible for managing calls and sensors. A version conflict, cache accumulation, or an error after a firmware update can lead to the sensor signals being ignored. Android The Phone system application and background process services are responsible for managing calls and sensors. A version conflict, cache buildup, or an error after a firmware update can cause sensor signals to be ignored.
To exclude the influence of third-party software, you need to start the device in Safe mode. In this state, only system applications are loaded, and all apps you have installed (messengers, launchers, optimizers) are blocked. If in this mode the screen goes dark correctly, then the problem is caused by some third-party application that has access to call control or overlay on top of other windows.
To enter safe mode on most models Xiaomi you need to hold down the power button, and then long press the "Shutdown" icon on the screen until you are prompted to reboot into safe mode. An alternative method is to hold down the volume down button while the device boots up after turning it off.
If the problem disappears, remember what applications you installed recently. Often the culprits are smart call blockers, voice recorders that record conversations, or screen recording applications. Removing them one by one will help you find the culprit.
Calibrating the proximity sensor through the engineering menu
On smartphones Redmi there is a hidden engineering menu that allows you to diagnose and manually calibrate the sensors. This is the most effective method of solving the problem if the sensor is physically working, but its readings are erroneous. The system may “think” that the distance to the object is always greater than normal, and therefore does not turn off the screen.
To enter the diagnostic menu, dial a special code in the "Phone" application. The interface may differ depending on the version MIUI, but the logic of actions remains the same. You will need to find the section responsible for the Proximity Sensor and start the calibration procedure.
##6484##After entering the code, the menu will open CIT (Customer Integration Test). Find the "Proximity sensor" item in the list. Click on it. You will see two values: distance in centimeters and status (Near/Far). Cover the sensor with your hand (without touching the glass) and make sure that the status changes to “Near” and the distance approaches zero. If the values do not change or change incorrectly, click the "Calibration" button at the bottom of the screen.
During calibration, do not remove your hand from the top of the phone. The process may take a few seconds. Upon successful completion, the message "Calibration Success" will appear. Be sure to restart the device for the new parameters to take effect.
☑️ Correct sensor calibration
Settings of the "Phone" application and Google services
In the latest versions of shells from Xiaomi and clean Android the calling application can be replaced with a standard solution from Google. This creates confusion in the settings, since the sensor control menu can be in different places depending on which application is used by default.
If you have an application installed Google Phone, go to its settings through the three dots in the corner. Find the "Incoming call settings" section. There may be an option to “Turn off the screen during a call” or settings for sensor sensitivity. Make sure that all switches are active.
If using the standard application MIUI, the path may vary. Clearing the data from the Phone application itself often helps. This will not delete your call history or contacts (they are stored in a separate storage), but it will reset the interface behavior settings.
| Application type | Settings path | Action |
|---|---|---|
| Google Phone | Settings → During a call | Check the sensor ticks |
| MIUI phone | Application settings → Advanced | Clear data |
| System | Settings → Advanced settings | Reset special settings. Features |
⚠️ Attention: Clearing Phone app data may reset your call forwarding or call waiting settings if they were set manually. Write them down before resetting if you use complex call routing schemes.
Problems with the display after replacement or repair
If your smartphone Redmi has recently been repaired, and a problem with the screen appeared immediately after that, the reason is almost certain lies in the quality of the installed display module. In original screens, the proximity sensor is often integrated into the cable or control board, and its operation is synchronized with the display controller.
In cheap analogues (copies), this sensor can be output with a separate wire, glued with tape in the wrong place, or absent altogether (emulated in software, which does not work well). The technician could simply forget to connect the sensor cable or damage it during assembly.
A critical sign of a poor-quality replacement is the lack of response of the sensor in the engineering menu even with full calibration. If the distance values in the CIT test do not change at all when you cover the top of the screen with your hand, it means that the physical connection is broken or the sensor is faulty.
It is also worth checking whether the cable connector inside the case has come loose. With strong impacts or poor assembly, the contact may become loose. In this case, lightly pressing the top frame of the phone sometimes temporarily restores operation, which confirms the problem with the contact.
How to check the cable yourself?
To do this, you will need to remove the back cover (if it is glass or plastic) and inspect the connection of the display cable to the motherboard. However, if the phone is under warranty, you absolutely cannot open it - you will lose the right to free repair.
Third-party applications for controlling the sensor
When standard methods do not help, utilities from the store come to the rescue Play Market, created specifically for forced calibration or emulation of the operation of sensors. These applications may have deeper access to the system or offer alternative data processing algorithms.
One of the popular solutions is the application Proximity Sensor Reset Fix. It automatically runs a series of tests and tries to clear driver errors. Another option is to use applications like GPS & Statusthat allow you to completely reset all device data (A-GPS, accelerometer, compass and proximity) with one click.
Use of such tools requires caution. Grant them only the permissions they need. After working with such utilities, be sure to completely reboot your smartphone, and not just turn off the screen.
- 📲 Download a proven application for calibrating sensors from the official store.
- 🔄 Start the procedure for resetting sensor data (Reset Sensors).
- 🔌 Reboot the device and check operation in normal call mode.
Hardware failure and the need for repair
If neither software calibration, nor removing the glass, nor resetting the settings helped, a physical breakdown of the component is likely. A proximity sensor is an optoelectronic device consisting of an infrared LED and a photodetector. Over time, the LED can degrade and simply stop emitting light of sufficient power.
Oxidation of the contacts on the board due to moisture ingress is also possible. Even if the phone did not sink, high humidity in the bathroom or condensation due to sudden changes in temperature can cause microscopic corrosion that disrupts signal transmission.
In this case, the only solution is to replace the sensor or the entire top cable (to which the front camera and speaker are often attached). In some models Redmi the sensor is soldered into the board, which requires professional soldering and a microscope.
⚠️ Attention: Do not try to heat the top of the phone with a hairdryer to “dry” the sensor. This may cause the polarizing film on the display to peel off or damage the battery. Entrust moisture diagnostics to specialists.
If the sensor does not respond in the engineering menu even after calibration and removal of protective glass, the problem is hardware in nature and requires a visit to service.
Frequently asked questions (FAQ)
Why does the screen turn off by itself when I don't hold the phone to my ear?
This is the opposite problem: the sensor is too sensitive or dirty. Dust on the sensor can create a persistent shadow, which the system perceives as an approaching object. Try cleaning the top frame thoroughly.
Does the dark theme affect the operation of the sensor?
No, the software theme (light or dark) does not affect the operation of the hardware sensors. However, if you have Always On Display (AOD) enabled, it may prevent the sensor from working correctly in some firmwares. Try disabling AOD in the settings.
Is it possible to completely disable the proximity sensor?
It cannot be disabled using standard Android tools, as this is a critical security feature. However, there are call launcher applications that ignore the sensor signal, but this will lead to accidental cheek presses.
Does a factory reset help?
A Factory Reset only helps if the problem is caused by a deep software conflict or a virus. If the problem is dirt, a broken cable or a defective screen, resetting the data will not solve the problem.
Why does the sensor work worse on the new Redmi Note than on the old ones?
Manufacturers are trying to reduce the screen bezels by hiding the sensor under the display. This technology is more difficult to set up and is more sensitive to the quality of protective glass than the classic location of the sensor in the cutout.