Owners of the legendary Xiaomi Mi3 often face a situation when during a phone conversation the screen goes out and stops responding to touches without lighting up even after the call is completed. This problem is associated with the incorrect operation of the proximity sensor, which mistakenly detects the presence of the smartphone near the ear or the overlapping of the upper part of the body.
It is not possible to completely “cut” this sensor from the system, as it is a critical element of security and ergonomics of the Android interface. However, there are effective methods of calibration, forced reset and bypass of locking that allow the device to return to normal functionality.
In this article, we will take a look at all the available solutions, from simple settings to the use of hidden engineering menus, you will learn how to adjust the sensitivity of the sensor correctly so that the screen goes off only when it is really necessary and stops locking in your pocket or when talking through a speakerphone.
The reasons for the incorrect operation of the sensor on Xiaomi Mi3
The main cause of the failure is a design feature of the Mi3, where the sensor is located under the glass at the top of the display. Over time, the glue that fixes the protective glass can become cloudy or shift, creating optical interference for the infrared emitter, which leads to the system constantly receiving a signal about the “approach” of the object.
The second common cause is software conflict after updating the MIUI firmware. New versions of the shell can misinterpret the readings of old sensors, requiring manual reconfiguration of the threshold values of the senses.
Also consider the effects of third-party accessories: Protective films or glass not specifically designed for the Xiaomi Mi3 may have an opaque edge that overlaps the sensor’s work area, and even microscopic dust or greasy spots in the area of the speaker can cause a false alarm.
⚠️ Warning: Before you start any manipulation, make sure that the screen does not have dense protective glasses with a wide black frame. Often the problem is solved by simply replacing the accessory with a better analogue with a notch under the sensor.
If physical factors are excluded, the software is likely to fail, in which case resetting or using special codes to access the system's diagnostic tools will help.
Basic configuration through the call menu
The easiest and safest way to try to fix the situation is to check the standard phone book and call settings, and some versions of MIUI have an option to control the behavior of the screen during a conversation, although it does not physically turn off the sensor itself.
You need to open the Phone app and go to the settings menu, usually hidden behind three dots or stripes in the corner of the screen. Find the item associated with Incoming Calls or Call Settings. There may be an option to turn off the screen when you touch your ear.
If the switch is active, try deactivating it. It won't take the sensor out of the system, but it can change the algorithm to make the response less aggressive, but on many global firmware, this option is hidden, and then you have to resort to deeper methods.
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If the standard call settings menu doesn't have the right switches, it means your version of MIUI is tightly regulated, so switch to the engineering menu.
It is important to understand that turning off the screen response can lead to accidental cheek presses during a conversation, so this method is especially suitable for situations where you often use a speakerphone or headset.
Use of the Engineering Menu for Calibration
The most effective solution is to log into a hidden engineering menu designed to test hardware components. For the Xiaomi Mi3, the code that allows you to access sensor testing is relevant. You will need to go to the Phone application and type the combination # # # #6484##.
Once you enter the code, you will see the CIT (Customer Information Test) menu, and you will find the "Proximity Sensor" or "Proximity Sensor" item in the test list, and you will click on it and you will see a screen with numerical values that change when you close the top of the phone with your hand.
The calibration process is as follows:
- 📱 Remove your hand from the top of the screen – the value should change (usually 5.0 or 0.0, depending on the version).
- 🖐️ Close the sensor with your palm – the value should change to the opposite (for example, from 5.0 to 0.0).
- 🔄 If values don’t change or change randomly, click the “Calibration” or “Calibrate” button at the bottom of the screen.
- ✅ After successful calibration, a message will appear “Pass” or “Success».
⚠️ Warning: Do not calibrate your phone with a case or bright direct sunlight. Infrared radiation from the sun can blind the sensor and calibration will be incorrect.
If automatic calibration doesn’t help, you can try manually resetting sensor settings through the development menu, but this requires deeper intervention in the system.
Reset sensor settings through the developer
In advanced versions of the MIUI shell, there is a hidden menu for developers to reset sensor settings, and to activate this menu, go to Settings → About Phone and quickly click on the MIUI version number seven times.
Once you have a “You’ve become a developer” message, go back to the main settings menu and select “Advanced Settings” → “Developers” and scroll down to the bottom of the “Input” or “Sensors” section.
This can be a Calibration or Sensor Reset, and clicking on it will trigger a reset of the services that are responsible for the accelerometer, gyroscope, and proximity sensor, which often helps if the failure is caused by software-based driver freeze.
You can also find the "Show Touch" or "Pointer location" option on this menu, and you can visually monitor whether the screen is responding to touch when the proximity sensor should be blocking it, which is a great way to diagnose.
What if the developer menu doesn’t have the right options?
Remember that any changes to the developer menu can affect the stability of other sensors. If the screen rotation stops after the reset, just restart the device.
Comparison of problem-solving methods
For the convenience of choosing the best way to troubleshoot, we have systematized the available methods in a table that will help you quickly assess the risks and effectiveness of each approach for your specific situation with the Xiaomi Mi3.
| Method | Difficulty | Efficiency | Risks. |
|---|---|---|---|
| Removal of the protective glass | Low. | High (if the cause is in it) | Lack of screen protection |
| Call settings | Low. | Medium | Accidental cheekstrokes |
| Engineering Menu (CIT) | Medium | Tall. | Incorrect calibration |
| Resetting through developer | Tall. | Medium | Failure of other sensors |
As can be seen from the table, the safest and often effective method is to check physical factors (films, dirt) and subsequent calibration through the scaling of the scaling system. CIT-Software resets should only be used if the hardware methods have not worked.
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A comprehensive approach combining sensor area cleaning and software calibration solves the problem 90% of the time without the need to flash the device.
Third-party applications for sensor control
If the system means to solve the problem fails, to help come applications from the Google Play store. There are utilities that allow you to forcibly turn off the proximity sensor or change the threshold of its sensitivity.
One popular solution is the Proximity Sensor Reset & Fix app, which runs rootless and allows you to reset your sensor settings in one click, and there are trick apps that emulate the sensor's operation, keeping the screen from going out.
However, using such programs has its disadvantages: they consume battery power in the background and can conflict with Android system processes, and the constant operation of the screen during a conversation will lead to a faster discharge of the Mi3 battery.
- 📲 Proximity OFF — Simple application with a single button to turn on/off the sensor.
- 🛠️ Sensor Box is a powerful tool for diagnosing and testing all sensors of the smartphone.
- 🔧 Fix Proximity Sensor – a utility for automatic calibration and resetting.
⚠️ Note: Download applications only from trusted sources. Deep-access programs may contain ad modules or malicious code, especially on older versions of Android installed on the Internet. Mi3.
Using third-party software is a last resort. Before installing additional applications, make sure you have tried all the regular features of the system.