Where is the proximity sensor on Xiaomi Mi 8 Pro: diagram, photo and health check

Introduction: Why you need a proximity sensor and why its location is important

The proximity sensor in Xiaomi smartphones is a small but critical component that is responsible for automatically turning off the screen during a phone call. When you hold the device to your ear, the sensor detects the obstacle and extinguishes the backlight, preventing accidental pressing and saving battery power. On the Mi 8 Pro model (codenamed equuleus), this sensor is integrated into the top of the display, but its exact location often raises questions among users, especially when diagnosing malfunctions.

Sensor problems are different: the screen doesn't go out during a call, buttons are accidentally pressed with the cheek, or the display turns off too soon. In 80% of cases, the fault is sensor contamination, damage to the plume or software failure. Knowing exactly where the proximity sensor on the Xiaomi Mi 8 Pro is will help quickly localize the problem and choose the right way to repair — from simple cleaning to replacing the module.

In this article, we'll look at not only the physical location of the sensor, but also the nuances of its operation, the typical breakdowns, and the ways to check without special equipment. If you encounter a sensor malfunction, here you will find step-by-step instructions for diagnosing and solving the problem.

The exact location of the proximity sensor on the Xiaomi Mi 8 Pro

On the Mi 8 Pro, the proximity sensor is located at the top of the screen, to the right of the speaker, which is a conversational one (when you look at the phone in portrait orientation). Specifically, this is a small hole with a diameter of ~1 mm hidden under the display glass. Unlike the newer Xiaomi models, where the sensor can be hidden under the matrix (as in the Mi 11), it uses a classic circuit with a separate infrared emitter and receiver.

Visually determine the location of the sensor can be on two grounds:

• 📍 Left of the front camera – if you look closely, you can see a barely noticeable blackout under the glass (this is a protective coating of the sensor).
• 🔍 Backlighting during testing – when you start an engineering menu or special applications (for example, Sensor Test), the sensor can glow red or purple.

For clarity, the following is a diagram of the location of the sensors in the upper panel of the Mi 8 Pro:

Important: on the Mi 8 Pro, the proximity sensor is aligned with the light sensor in one module, but they are physically separated, and the damage to one may not affect the other.

How to check the performance of the sensor without disassembling the phone

Before you carry your phone for repair, you should make sure that the problem is really in the sensor, not the software.

1. Testing through the Engineering Menu: Enter the Phone app code ##6484## (or #4636## → Equipment Testing) and in the Proximity Sensor section, put your hand to the top of the screen – the value should change from 5 (no obstacle) to 0 (there is an obstacle).
2. Diagnostic apps: Install tools like Phone Doctor Plus or Sensor Test from Google Play, which will show the sensor's response in real time. Normal values: 0-5 cm is triggered, >5 cm is no reaction.
3. Manual test during the call: Call another phone and cover the top of the Mi 8 Pro with your palm. The screen should go out in 1-2 seconds. If this does not happen or it goes out too quickly, the sensor is faulty.

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

• 🧹 Sensor pollution (dust, fat, protective film).
• 🔌 Damage to the plume (often after falls or disassembly).
• 🤖 Firmware failure (solved by flashing or resetting settings).

Clean the top of the screen with alcohol | Check the reaction in the engineering menu |Install the sensor test app |Try to call and cover the sensor with your hand-->

Typical malfunctions of the proximity sensor and their causes

On the Xiaomi Mi 8 Pro, the following problems with the proximity sensor are most common:

One of the most common reasons is poor quality protective film, and many of the films have an opaque layer in the sensor area that blocks the infrared signal, so if you've recently glued a new film and you've encountered a problem, try removing it or cutting a hole over the sensor.

Another common problem is the failure after the MIUI update. For example, after upgrading to MIUI 12.5, some users complained about the sensor’s malfunction, in which case the rollback to the previous version or resetting to factory settings helps (don’t forget about backup!).

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If the sensor stopped working after the phone fell, do not try to disassemble it yourself - in the Mi 8 Pro, the sensor plume is very fragile and easily breaks.

How to Clean Up the Approach Sensor on Xiaomi Mi 8 Pro

If tests show that the sensor is weak or unstable, the first thing you should do is clean it.

• 🧴 Isopropyl alcohol (70% or higher).
• 🧻 Soft lilac-free napkin (for example, for glasses).
• 🔦 Lantern (for illumination).
• 🧲 Plastic spatula (optional if you need to tamper with the film).

Step-by-step:

1. Turn off the phone.
2. Hold the flashlight to the top of the screen to see the location of the sensor (it will look like a small dot under the glass).
3. Moisten the napkin with alcohol and gently wipe the sensor area without pressing (you can not press on the glass!).
4. If the phone is glued to a protective film, try to gently lift its edge above the sensor and wipe alcohol under it.
5. Let the phone dry for 5-10 minutes, then turn on and check the sensor.

⚠️ Warning: Do not use cotton swabs or sharp objects - they can scratch the glass or damage the sensor.

If cleaning didn't work, the problem could be deeper, like oxidizing the contacts on the board or damaging the plume, in which case you'd need to disassemble the phone.

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

Replacement of the proximity sensor with the Xiaomi Mi 8 Pro is required in the following cases:

• 🔧 Mechanical damage to the sensor (crack, chipping).
• 🔌 Breaking of the plume (often after falls or unsuccessful disassembly).
• 💧 Corrosion of contacts due to moisture.
• 🔄 The sensor does not respond even after flashing and cleaning.

The cost of repair depends on the method of replacement:

If you decide to replace the sensor yourself, consider:

• 🛠️ You will need a special set of screwdrivers (Torx). T3, T4) and mediator.
• 🔥 The risk of damaging the battery plume or display is very fragile.
• 📱 After replacement, the sensor may need to be calibrated through the engineering menu.

⚠️ Attention: On the Mi 8 Pro, the soldering sensor approaches the top plume. If you don't have experience soldering microelectronics, it's better to replace the entire plume or contact the service.

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If the sensor is replaced, the screen becomes dim or artifacts appear, the plume of the display is likely to have been damaged, in which case it will need to be replaced or repaired.

Software Ways to Solve Sensor Problems

It's not always hardware that's the problem. Often the proximity sensor on the Mi 8 Pro gets glitzy because of software failures.

1. Reset the sensor settings via the engineering menu: Enter the code ##6484##, select Proximity Sensor and press Calibrate. After rebooting, check the work.
2. Factory Firmware Retracement: If the problem has occurred after the MIUI update, try retracing the previous version via Fastboot or Recovery. Instructions are available on the 4PDA forum in the Mi 8 Pro theme.
3. Disabling energy saving functions: Sometimes MIUI aggressively optimizes sensors. Go to Settings → Battery → Power saving mode and turn it off.
4. Custom core installation: For advanced users: some custom cores (e.g. FrancoKernel) work better with sensors. Requires an unlocked bootloader.

If the sensor is unstable (it works, it doesn't), try to turn off the Smart Screen Lock feature in the call settings. Sometimes it conflicts with the proximity sensor.

Note: Some firmware (e.g. MIUI EU) may not be able to calibrate the sensor through the engineering menu, in which case only manual editing of configuration files or flashing will help.

Frequent questions about the proximity sensor on Xiaomi Mi 8 Pro