How to check the proximity sensor on Xiaomi Redmi Note 8 Pro

The Xiaomi Redmi Note 8 Pro is a popular smartphone with a powerful filling, but even it is not immune to hardware failures. One of the common problems is that the proximity sensor stops working correctly. This is manifested in the fact that the screen does not go out during the call, accidentally pressed buttons with the cheek, or the sensor does not respond at all to the approach of the hand, the reasons can be different from a software failure to physical damage to the module.

In this article, we will discuss 5 working methods for checking the proximity sensor on the Redmi Note 8 Pro, from simple tests through the engineering menu to hardware diagnostics with a multimeter. You will learn how to distinguish sensor malfunction from firmware problems, and what to do if the sensor fails. All instructions are adapted specifically for the M1906G7G model (codenamed begonia) and tested on current versions of MIUI 12-14.

What is the proximity sensor and how it works in the Redmi Note 8 Pro

The proximity sensor in the Redmi Note 8 Pro is an infrared sensor located at the top of the screen next to the speaker, and its main task is to turn off the touch screen during a phone conversation when you bring the device to your ear, which prevents accidental pressing and saves battery power.

Principle of work:

• 📶 Infrared LED emits an invisible signal.
• 🔄 Photodiode picks up a signal reflected from an object (like your head.
• 📱 The controller analyzes the data and sends a command to turn off the screen.

The Redmi Note 8 Pro uses the STK3311 sensor (or similar APDS-9960 in some revisions), which is regulated by firmware, but may decrease over time due to glass contamination, plume damage, or chip failure.

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If the sensor stopped working after the smartphone fell, first check the integrity of the glass above the sensor – cracks or chips can block the infrared signal.

Signs of malfunction of the proximity sensor

How do you know if the sensor is the problem, not the firmware or the screen?

If symptoms only appear in certain apps (like WhatsApp or Telegram), the problem is likely in the messaging settings, not the hardware. Try turning off the "Screen is always on" feature in the call settings.

⚠️ Note: On the Redmi Note 8 Pro with custom firmware (for example, Pixel Experience or LineageOS), the proximity sensor may not work properly due to the lack of drivers. MIUI sensor-enabled core.

Method 1: Check through the engineering menu (code ##6484##)

The fastest way to diagnose is to use a hidden engineering menu, which is available on all Xiaomi smartphones without root rights.

Instructions:

1. Open the Phone app.
2. Enter the combination: ##6484### (some firmware may require ##64663###).
3. Select Proximity Sensor (Proximity Sensor).
4. Cover the top of the screen with your hand – the value should change from 5.00 cm to 0.00 cm.

If the values do not change or if the Sensor not available error is displayed, this indicates:

• 🔧 Hardware malfunction of the sensor or plume.
• 📱 Software failure (solved by resetting or flashing).
• 🛠️ Sensor pollution (dust, fat, protective film).

Make sure there is no protective film on the screen |Close all background apps |Check battery power (minimum 20%)|Use a clean hand without gloves-->

Method 2: Application Testing (CPU-Z)

If the engineering menu is not available or does not show data, use third-party utilities, which visualize the operation of the sensor and help identify problems.

Top.-3 diagnostics:

• 📊 Sensor Test (by Innovative Apps) – shows a real-time graph of sensor response.
• 🔍 CPU-Z — Sensors displays the status of all sensors, including proximity.
• 🛠️ Phone Doctor Plus – conducts a comprehensive test of hardware components.

How to check:

1. Install one of the applications (e.g., Sensor Test).
2. Run the proximity sensor test.
3. Cover the top of the smartphone with your hand – the graph should show a sharp drop in value to 0.
4. Remove your hand – the value should return to 5 (maximum distance).

⚠️ Note: Redmi Note 8 Pro with MIUI 13+ Some sensor testing applications may not show data due to security limitations. ADB (see method 4).

Method 3: Calibration of the sensor through hidden MIUI settings

Sometimes the proximity sensor doesn't work properly because of a miscalibration setting, and MIUI has a hidden partition for manual sensitivity adjustment.

How to open the calibration menu:

1. Go to Settings. → The phone.
2. Press 5-7 times on the MIUI version until the message “You are a developer” appears.
3. Return to the main settings menu and open Additional settings → For developers.
4. Activate the option to Enable debugging via USB.
5. Go back and find the Calibration of the proximity sensor (could be called Proximity Sensor Calibration).
6. Follow the instructions on the screen – usually cover the sensor with your hand and wait for the process to complete.

If there is no calibration point, try an alternative method:

adb shell settings put global proximity_delay 1000

This command increases the sensor delay to 1 second (in milliseconds). After entering, restart the smartphone.

Method 4: Checking through ADB (for advanced users)

If standard methods fail, you can test the sensor using Android Debug Bridge (ADB), which requires connecting the smartphone to a PC, but gives the most accurate data.

Step-by-step:

1. Download and install ADB Tools on your computer.
2. Enable USB debugging on your smartphone (see Method 3).
3. Connect the Redmi Note 8 Pro to the PC USB-cable.
4. Open the command line (Windows) or terminal (macOS/Linux) and type:

adb devices

Make sure the device is identified. Then type in:

adb shell dumpsys sensorservice

In the conclusion, look for the Proximity Sensor block.

• handle - Sensor ID (should not be 0).
• enabled - true status (if false, the sensor is disabled by the system).
• Values - current readings (should change when the sensor is covered).

If the output is missing the proximity block or the value is always 5.0, this confirms the malfunction.

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ADB-verification is the most reliable method of diagnosis, since the data is read directly from the sensor controller, bypassing the shell. MIUI.

Method 5: Hardware inspection (multimeter and disassembly)

If the software didn't detect any problems, but the sensor didn't work, then the hardware diagnostics would be left, and that would require disassembling the smartphone and checking the sensor's power circuits.

Tools required:

• 🔧 Set of screwdrivers (cross, flat, suction cup for the screen).
• 📟 Multimeter (Diode or Resistance Checking Mode).
• 🧴 Alcohol and cotton swabs to clean contacts.

Procedure:

1. Turn off your smartphone and remove it. SIM-map.
2. Carefully put the back cover (it is held on the latches).
3. Unscrew the screws holding the metal plate above the screen plume.
4. Disconnect the proximity sensor plume (located next to the front camera).
5. Call the contacts of the plume multimeter: the resistance between the VCC and GND should be ~1.8-2.0 kOhm. VCC voltage with the phone on is ~2.8 V.

Clean the contacts of the plume with alcohol and connect back.

⚠️ Note: On the Redmi Note 8 Pro, the proximity sensor plume is often combined with the front camera plume. When disassembling, do not pull the wires - they are fragile and can break! If the sensor does not work after cleaning the contacts, you will need to replace the module (cost) ~500–800 ₽).

What to do if the proximity sensor is not working

If the diagnosis confirmed the malfunction, here is the algorithm of actions:

If you're not sure about your soldering skills, you should contact the service. On the Redmi Note 8 Pro, the solder sensor approaches the tail of the front camera, and its replacement requires accuracy - if the plume is damaged, you will have to change the entire module (cost). ~2500 ₽).

Provisional solution (before repair):

• 📱 Turn off the "Screen is always on" function in the call settings.
• 🔕 Use a headset or speakerphone.
• 🛠️ Install Proximity Sensor Fix (not working on all firmware).

FAQ: Frequent questions about the proximity sensor on the Redmi Note 8 Pro