How to find the proximity sensor on Xiaomi Redmi Note 8: location, inspection and repair

The proximity sensor in the Xiaomi Redmi Note 8 is a small but critical element that automatically shuts down the screen during a phone call. When you hold your phone to your ear, the sensor detects the obstacle and extinguishes the backlight, preventing accidental taps and saving battery power. However, over time, this module can fail: the screen does not turn off when you call, reacts with a delay or, conversely, goes out for no reason. If you encounter such problems, the first thing you need to precisely localize the sensor and check its performance.

Many users mistakenly look for a proximity sensor on the back of a smartphone or next to the main camera. It's actually located on the front of the device, and it requires careful searching. In this article, we'll go into detail about where the sensor on the Redmi Note 8 is, how to visually identify it, and also check it without disassembling the phone. If the problem turns out to be hardware, you'll find out if you can replace the sensor yourself and how much it costs.

⚠️ Before starting a diagnosis, make sure that there is no protective film or glass on the screen that covers the sensor area. Even a thin layer of film can block the infrared signal and simulate a malfunction.

Where is the proximity sensor on Xiaomi Redmi Note 8: the exact location

On the Xiaomi Redmi Note 8, the proximity sensor is built into the top of the screen, next to the speaker of the talking device, specifically located to the left of the front camera (when you look at the phone in the standard position), visually it is difficult to notice, since it is hidden under the black glass of the display and has no external holes — unlike a microphone or LED indicator.

To get a better look at the top of the screen:

• 📱 Front camera - is in the center in the cutout ("drop").
• 🔊 Speaker – to the right of the camera (if you hold the phone vertically).
• 👁️ The proximity sensor is on the left of the camera, under glass, and it's usually in a spot or a small circular spot with a diameter. ~1 mm.
• 💡 Light sensor – often located next to the proximity sensor (sometimes they are combined into one module).

On some Redmi Note 8 models, the proximity sensor can be combined with the light sensor in a single chip, in which case you will see only one small hole on the outside, but functionally it is two independent sensors. To confirm the location, you can use a flashlight: in bright light, the light sensor must respond to the change in the brightness of the screen, and the proximity sensor does not.

What the proximity sensor looks like: photo and diagram

Visually, the proximity sensor on the Redmi Note 8 is a miniature infrared sensor that looks like a tiny black dot or a translucent spot under glass. It has no moving parts or protruding elements — only a flat surface.

If you're taking off a safety glass or a film, be careful: the proximity sensor is easily damaged by sharp objects. In some Redmi Note 8 batches, the sensor can be shifted closer to the edge of the frame -- it's not a defect, it's a feature of the build. To make sure it's there, you can use a lens or a macro lens of another smartphone.

⚠️ Note: Do not confuse the proximity sensor with an infrared port (if your model has one), the latter located on the upper end of the case and used to control equipment through the Xiaomi remote control.

How to check the operation of the proximity sensor without disassembling the phone

Before you disassemble the Redmi Note 8, make sure that the problem is with the sensor, not the software.

1. Testing through the engineering menu: Dial on the phone keyboard code ##6484## (or ##4636## → "Equipment Testing"). In the menu that opens, select Proximity Sensor. Bring your hand to the top of the screen - the value should change from 5 (no obstacle) to 0 (there is an obstacle).
2. Check through the app: Install Phone Tester or Sensor Box from Google Play. In the Sensors section, find Proximity and test your hand's approach response.
3. Visual test: Call the phone and hold it to your ear. The screen should go out in 1-2 seconds. If it stays on or goes out with a delay of >3 seconds, the sensor is faulty.

If the sensor does not respond in any of the tests, the problem may be:

• 🧹 Sensor contamination (dust, fat, film glue residues).
• 🔧 Damage to the plume (for example, after a phone drop).
• 🖥️ Firmware failure (solved by resetting settings or flashing).
• 💥 Physical breakdown of the sensor (replacement required).

Call the engineering menu (#6484##)

Install an application for sensor test

Check the screen reaction during the call

Examine the sensor for contamination

Reset your phone settings (if software problem)-->

Cleaning the proximity sensor: step-by-step instructions

Most of the time, the sensor will stop working because of the buildup of dirt or grease on the surface, and you can clean it yourself without disassembling the phone.

• 🧴 Alcohol wipes (or cotton swab) + isopropyl).
• 🔦 Lighting lamp.
• 🧲 Lupa (optional, for accuracy).

Sequence of action:

1. Turn off your phone to avoid accidental tapping.
2. Bring the flashlight to the top of the screen at an angle - this will help to see the location of the sensor.
3. Moisten the cotton swab in alcohol and gently wipe the sensor area (don't press hard!).
4. Let the alcohol evaporate (1-2 minutes) and turn on the phone.
5. Check the sensor through an engineering menu or test call.

⚠️ Note: Do not use abrasive materials (such as toothpaste) or metal objects. Even micro-scratches on the glass above the sensor can impair its sensitivity.

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If the sensor still doesn't work after cleaning, try calibrating it through the Proximity Sensor Reset app (available on Google Play).

Replacement of the proximity sensor: when it is needed and how much it costs

If cleaning and software methods didn't work, it's likely that the sensor is physically out of order, which would require a replacement. On the Xiaomi Redmi Note 8, the proximity sensor is soldered into a flexible plume that also includes a front-facing camera, speaker and light sensor, which means that you can't replace the sensor alone, you have to change the entire module.

The cost of repair depends on the region and the service center:

For a self-replacement, you will need:

• 🛠️ Set of screwdrivers (star) T3, T4).
• 🔥 Hair dryer or glue heating station.
• 🧲 Screen suction cup.
• 📦 New plume (for example, art. Xiaomi Redmi Note 8 Proximity Flex Cable).

⚠️ Note: If you replace yourself, you risk damaging the display plume or battery. If you do not have experience repairing smartphones, you should contact the service. Also note that after disassembly, the leakiness may fly, and the phone will lose protection from dust.

Software glitches: how to reboot or calibrate the sensor

Sometimes the proximity sensor on the Redmi Note 8 stops working due to a firmware failure or miscalibration, in which case the following steps help:

1. Reboot phone: Simple but effective way. Press the power button and select Reboot. Check the sensor after you turn on.
2. Sensor reset: Install the Proximity Sensor Reset app from Google Play. It resets the sensor calibration to factory values.
3. MIUI Update: Go to Settings → About Phone → System Update and check for new firmware versions. Sometimes sensor bugs are patched.
4. Reset to factory settings: If nothing helps, complete reset: Settings → Additional → Reset and Reset → Reset. Attention! This will delete all data from the phone.

If the sensor doesn’t work properly after installing custom firmware (like LineageOS or Pixel Experience), the problem may be the lack of drivers, in which case go back to the official MIUI or find firmware that supports all sensors.

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Before resetting, be sure to back up your data through Settings → Additional → Backup or Mi Cloud.

Frequent questions about the proximity sensor on the Redmi Note 8