Xiaomi proximity sensor: where is located, how it works and what to do in case of malfunction

The proximity sensor in Xiaomi smartphones is a small but critical component that automatically shuts down the screen during a phone call. When you bring the device to your ear, the sensor detects the obstacle and extinguishes the backlight, preventing accidental pressing and saving battery power. However, many users face problems: the screen does not turn off when you call, the sensor stops responding or, conversely, the device “gluts” without a reason.

In this article, we will look at where the proximity sensor is located in popular Xiaomi models (from budget Redmi to flagship Mi and POCO), how to identify it visually, and provide practical tips for troubleshooting. You will learn whether you can calibrate the sensor programmatically when you need physical repairs, and how to avoid typical errors when you check yourself.

What is a proximity sensor and why you need it

The proximity sensor is an optoelectronic module that consists of an infrared LED (IR-LED) and a photodiode. The principle is simple: the LED emits infrared light that is invisible to the human eye, and the photodiode captures its reflection from objects near the screen. If the reflected signal is strong enough (for example, when you hold the phone to your ear), the system knows that the screen needs to be locked.

The main functions of the sensor:

• 📞 Automatically locking the screen during a call (prevents accidental tapping of the cheek or ear).
• 🔋 Saving battery power by turning off the backlight at unnecessary moments.
• 🛡️ Protection against false alarms of touch buttons (for example, in a pocket).
• 🎧 Interaction with accessories (for example, turning off the screen when approaching wireless headphones).

In Xiaomi smartphones, the proximity sensor is often combined with a light sensor (to automatically adjust the brightness of the screen), which saves space on the front panel, but complicates the diagnosis: if one of the sensors fails, the second may not work correctly.

⚠️ Note: Some Xiaomi models (e.g. Redmi Note 10 Pro) POCO X3 Pro) the proximity sensor is hidden under the display and visually invisible. Do not try to find it by external signs - use special tests or service menus.

Where is the proximity sensor in Xiaomi smartphones: location by model

The location of the sensor depends on the design of the front panel and the generation of the device, and in most cases it is located at the top of the screen, next to the front camera or speaker. Below we have shown the diagrams for the popular series.

If your model is not listed in the table, use the universal rule: the sensor is always next to the front camera or speaker. In modern smartphones (2022 and later), it is often hidden under the screen, so it may not be visible on the outside.

How to check the operation of the proximity sensor: step-by-step instructions

If the sensor is not working properly (the screen does not go out when you call or, conversely, is blocked for no reason), first make sure that the problem is not in the software settings.

1. Check your call settings: Go to Settings → Apps → Phone → Incoming calls and make sure that the proximity sensor option is enabled. In some firmware (e.g. MIUI 14), this item may be called Autolock when calling.
2. Run the sensor test: Dial the phone app code ##6484## (or #4636### → Equipment Testing). In the menu that opens, select Proximity Sensor. Put your hand to the top of the screen, and the value should change from 5.0 cm to 0.0 cm.
3. Use third-party apps: Install Sensor Test or Phone Tester from Google Play, which shows all sensors in real time, and if the proximity sensor values don't change when you put your hand up, it's faulty.
4. Check physical cleanliness: If the sensor is located in a separate hole (like in the Redmi A1), inspect it for contaminants. Dust or fat can block the infrared signal. Clean the hole with a soft brush or compressed air.

If after all the manipulations the sensor does not respond, the problem may be:

• 🔧 Software failure (resetting or flashing required).
• 🔌 Damage to the plume (for example, after falling or disassembling the phone).
• 💥 Failure of the sensor itself (replacement is required).

⚠️ Note: In smartphones with AMOLED-screens (e.g. Xiaomi) 12T or POCO F4) The proximity sensor may conflict with the Always On Display function. Turn it off in the settings if you notice false positives.

Typical malfunctions of the proximity sensor and their causes

The proximity sensor failures rarely occur by themselves, usually caused by external factors or user errors.

1.The screen doesn't go out during the call

Reasons:

• 📱 Sensor disabled in settings (see section above).
• 🧹 Sensor pollution (dust, fat, moisture).
• 🔄 Firmware failure after update MIUI.
• 🛠️ Damage to the flexible plume (for example, after changing the screen).

2.The screen is locked arbitrarily (without a call)

Reasons:

• 👤 False positives due to a cover or protective glass covering the sensor.
• 🔋 Overheating of the phone (the sensor can "glutch" at high temperatures).
• 🤖 The conflict with battery optimization (in) MIUI Some applications can block sensors).

3.The sensor is working "once again"

Reasons:

• 🔌 Bad contact of the plume (you need to reconnect in the service center).
• 📉 Sensor wear (typical for devices older than 3-4 years).
• 🧲 Effect of magnetic interference (e.g. from a magnet case).

If a malfunction occurs after a phone crash or self-repair, there is a 90% chance of physical damage, and only a diagnostic at the service center will help.

How to Calibrate the Approximation Sensor in Xiaomi

In some cases, the sensor is not working properly because of a miscalibration setting, which can be fixed without disassembling the phone using hidden MIUI menus.

1. Open the engineering menu: Dial the code ##6484## in the phone app. If it doesn't work, try ##4636## → Equipment Testing.
2. Select Proximity Sensor: In the window that opens, you will see the current sensor readings. Normal values are 5.0 cm (no obstacle) and 0.0 cm (obstacle detected).
3. Start calibration: Press Calibrate (or Reset Calibration). Follow the instructions on the screen - usually you need to bring and remove your hand several times.
4. Reboot the phone: After calibration, be sure to restart the device so that the changes take effect.

If your phone doesn’t have a calibration option, try resetting to factory settings (Settings → About Phone → Reset). In 80% of cases, a software reset solves problems with false sensor alarms if they are caused by a software failure.

💡

Before calibration, remove the cover and protective glass - they can distort the sensor readings.

If calibration doesn’t work, check the sensor in safe mode (press the power button → Safe Mode).If the sensor is working normally in this mode, the problem is in one of the installed applications (most often in launchers or optimizers).

What to do if the proximity sensor breaks: repair or replacement

If all the software methods have been tried, but the sensor still doesn't work, there are two options: repair or replacement. Let's look at both.

1. Repair (cleaning, soldering)

Suitable if the problem is:

• 🧹 Sensor pollution (dust, moisture).
• 🔌 Detached plume (for example, after changing the screen).
• 🔥 Oxidation of contacts (due to fluid ingestion).

Cost: 500 to 1500 rubles (depending on the model), in most cases, it is enough to clean the sensor with alcohol or reconnect the plume.

Replacement of the sensor

Required if:

• 💀 Sensor physically damaged (crack, chipping).
• 🔄 Neither calibration nor cleaning helps.
• 📉 Device older than 3 years (natural wear).

Cost: from 1000 to 3000 rubles (including work). In some models (for example, Xiaomi 12 Pro) sensor is assembled with a front camera, which is more expensive to repair.

⚠️ Note: Do not try to replace the sensor on your own in models with AMOLED-screens (e.g. Xiaomi 13 Ultra or POCO F5). Here, the sensor is integrated into the display module, and its replacement requires a complete disassembly of the phone and special equipment.

If you decide to repair your phone yourself, order the original sensor on AliExpress or in specialty stores (for example, FixPrice).

• 🔧 Set of screwdrivers (Torx) T3, T4).
• 🧲 Screen suction cup.
• 🔥 Hazel-softening.
• 📱 Disassembly schemes for your model (search on YouTube or 4PDA).

💡

Self-replacement of the proximity sensor is justified only for budget models (for example, Redmi 9A or POCO M3). In flagships, the risk of damage to the plume or display is too high - entrust the repair to professionals.

How to extend the life of the sensor approach: tips for care

The proximity sensor is not a component that breaks down every day, but improper operation can shorten its lifespan.

• 🚫 Avoid mechanical damage: do not drop the phone screen down and do not press on the top of the case.
• 🧼 Clean the sensor hole regularly: use a soft brush or compressed air (do not blow in with your mouth - moisture can damage!).
• 🔋 Do not use uncertified charges: voltage surges can disable not only the battery, but also sensors.
• 📱 Update the firmware: in new versions MIUI Often fix sensor bugs.
• 🧲 Avoid magnetic covers: they can interfere with the infrared signal.

If you talk on the phone frequently in dusty or wet conditions (such as on a construction site or in a workshop), use a tape with a cut-out under the sensor or special covers with pollution protection.

Also worth paying attention to the energy saving settings. In Ultra-saving mode, some sensors (including the proximity sensor) can turn off to save charge. Check for exceptions in Settings → Battery → Energy Saving.

FAQ: Frequent questions about the proximity sensor in Xiaomi