Where is the proximity sensor in Xiaomi Poco X3 and how to work with it

Xiaomi Poco X3 is a popular smartphone with great price-quality ratio, but even it sometimes has problems with the proximity sensor.This small but important component is responsible for turning off the screen during a conversation, preventing accidental cheek pressing. If the sensor is not working correctly, you risk interrupting the call, activating functions with your voice or facing a rapid battery discharge.

In this article, we will detail where the proximity sensor in the Poco X3 is physically located, how to identify it visually, and what to do if it stops functioning correctly, and you will also learn about typical malfunction signs, diagnostic methods and repair methods, from software to hardware.

Poco X3 top panel anatomy: where to look for sensor

In the Xiaomi Poco X3 (M2007J20CG and M2007J20CI models), the proximity sensor is integrated into the top display module, next to the front camera and speaker. Specifically, it is to the right of the speaker, under the protective glass, and visually looks like a small circular hole with a diameter of ~2 mm with a translucent coating.

To better localize it:

• 📱 Take a smartphone and look at the top of the screen (with the display on).
• 🔍 Hold a flashlight: the sensor will be slightly translucent, unlike the opaque elements of the camera.
• 🎯 On Poco. X3 NFC It is closer to the right (see the screen).

Important: Don't confuse it with a light sensor, which is located to the left (closer to the center of the top panel) and is responsible for automatic brightness control. Both sensors are often combined into one module, but their functions are fundamentally different.

How the approximation sensor works: the principle of operation

The Poco X3's proximity sensor uses infrared (IR) to work, and it emits a beam that's invisible to humans and analyzes the signal that's reflected, and when you hold the phone to your ear, the beam bounces off a surface (like skin) and comes back, and the smartphone recognizes it as "approach," and turns off the screen.

Specifications of the sensor in Poco X3:

Interestingly, the Poco X3 Pro (model M2102J20SG) uses a similar sensor, but with improved sensitivity due to the updated STK3311 controller. If your sensor has become worse after the MIUI update, the problem may lie in the firmware, not in the hardware.

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To check the sensor's performance without calling, open the engineering menu with code ##6484## and select Proximity Sensor. Here the current value is displayed (0 - nothing nearby, 1 - an obstacle is detected).

Signs of malfunction of the proximity sensor

If the sensor begins to "glutch", this is manifested by the following symptoms:

• 📵 The screen does not go out during the call (remains active, leading to occasional taps).
• 🔄 The screen goes off arbitrarily, even when the phone is on the table.
• 🔋 Fast battery discharge (sensor is constantly active).
• 🎧 Problems with connecting the headset (the smartphone “thinks” you’re talking on the phone).
• 🔊 The sound switches between the speaker and the tube for no reason.

The most common cause is sensor contamination, and dust, sweat, or residues from a protective film can block the infrared signal, and less often, it's the fault of:

• 🛠️ Mechanical damage after falling (cracks on the glass above the sensor).
• 💻 Firmware failure (especially after update) MIUI before version 12.5+).
• 🔌 Oxidation of the contacts of the display plume (if the phone has been in a wet environment).

Step-by-step diagnostics of the proximity sensor

Before you carry your phone to the service, try checking the sensor yourself:

1. Visual inspection: Light the top panel with a flashlight. The sensor should be clean, free of scratches or dirt. If you see debris, carefully remove it with a soft brush (do not use alcohol or wet wipes!).
2. Software Test: Open the Phone app and dial ##4636##. Select Testing → Proximity Sensor. Close the sensor with your finger - the value should change from 5.0 (no obstacle) to 0.0 (there is an obstacle).

Real-world verification

Poco X3

Clean the sensor from contamination|Check the work in the engineering menu|Update MIUI last-minute|Reset network settings (Settings) → SIM-maps and mobile networks → Reset)|Testing with another SIM-card-->

If the sensor does not respond at all (the value in the test does not change), the problem may be:

• 🔌 Display plume - check if the contacts have left (disassembly is required).
• 💾 Firmware – try to roll back to the previous version MIUI.
• 🔧 The sensor itself will require a replacement (cost) ~500-800 rubles with work).

Software solutions to problems

In 60 percent of cases, the Poco X3's proximity sensor malfunctions are software-related.

1. Phone reboot: Banal but often helps. Press the power button and select Reboot.
2. Clean the system cache: Go to Settings → About Phone → Memory. Click Clear Cache (not to be confused with Settings Reset!).
3. Resetting network settings: Settings → SIM-maps and mobile networks → Resetting network settings This can help if the failure is caused by a conflict with the communication module.
4. MIUI Update: Go to Settings → About Phone → System Update. If a new version is available, install it (especially for MIUI 12.0.3-12.0.8, where there were bugs with sensors).

Retrace to factory settings

⚠️ Warning: This will delete all data! pre-backup through Settings → Additionally. → Backup and reset.

If the problem occurs after the update MIUI 13, try to roll back on MIUI 12.5 via Fastboot. Instructions are available on the forum 4PDA POCO-themed X3.

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Before resetting, check if the In-pocket mode is on in Settings → Screen → In-pocket. Sometimes it conflicts with the proximity sensor.

Hardware repair: when without service can not do

If the software methods don't work, you'll have to intervene in the hardware.

• 🔧 Replacement of protective glass: If there are cracks on the glass above the sensor, they can block IR-The cost of replacement is from 1000 rubles.
• 🛠️ Cleaning/replacement of the display plume: Oxidation or break of contacts is a common cause of malfunction.
• 🔄 Replacement of the proximity sensor: the sensor itself is ~300 rubles, but with work the price will rise to 1000-1200 rubles. X3 It is soldered to a flexible display board, so a soldering station is required.

Can you replace the sensor yourself? Theoretically, yes, but:

• 🔨 You will need to disassemble the phone (risk of damaging the plumes).
• 🔥 Need skills to work with a soldering iron (sensor soldered to the board).
• 📦 You need to buy the original sensor (on AliExpress often sell non-working analogues).

⚠️ Warning: If you've never taken down smartphones, don't take risks! at Poco X3 The battery plume is easy to break, and the replacement will cost in 2000.+ ruble.

Alternatively, buy a used display module with a working sensor on Avito or Yule (price ~2,000-2500 rubles). But make sure the seller tested the proximity sensor before selling!

Prevention: how to prolong the life of the sensor

To make the proximity sensor in the Poco X3 last longer:

• 🧼 Regularly clean the top panel with a soft napkin (without alcohol!).
• 📱 Avoid falls – even small impacts can shift the sensor relative to the body.
• 💧 Do not use your phone in wet conditions (bath, swimming pool, rain).
• 🔄 Update. MIUI, But don’t install the beta versions (they often have sensor bugs).
• 🛡️ Use high-quality cases that do not press on the top of the screen.

If you make frequent calls in dusty environments (such as construction sites), stick a thin transparent film on the sensor (sold in electronics stores) that protects against pollution without blocking it. IR-signal.

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In the Poco X3 Pro, the proximity sensor is more dust-proof thanks to improved enclosure sealing. If you are experiencing frequent problems, consider upgrading to the Pro version.

FAQ: Frequent questions about the proximity sensor in the Poco X3