Xiaomi’s “proximity sensor fail” error: why it occurs and how to fix it

Have you ever noticed that when you call your Xiaomi screen doesn't turn off when you hold your phone to your ear? Or, conversely, it goes off for no reason when you just hold the device in your hands? Most likely, the problem lies in a malfunction of the proximity sensor. The proximity sensor fail error is one of the most common hardware problems in Xiaomi, Redmi and other smartphones. POCO, which may occur due to software failures or physical damage to the module.

In this article, we'll look at what the proximity sensor is, why it fails, and most importantly, how to diagnose and fix a problem yourself. You'll learn which Xiaomi models are most susceptible to this problem, what tools you'll need to repair, and when to go to the service center. And if you're not sure that the sensor is the problem, we'll teach you how to distinguish it from other faults, such as a display or firmware malfunction.

What is the proximity sensor and how does it work in Xiaomi

The proximity sensor is a small infrared module that sits at the top of the smartphone screen, usually next to the speaker and the front camera. Its main task is to detect when you bring the phone to your ear while you're talking. When the sensor picks up an obstacle (like your head), it sends a signal to the system, and the screen automatically shuts down. This prevents you from accidentally pressing your cheek or ear on touch buttons.

Xiaomi smartphones most often use infrared proximity sensors, which consist of:

• 🔦 IR emitter – sends a light signal invisible to a person;
• 👁️ IR receiver – captures the reflected signal and analyzes it;
• 📱 Controller – processes data and transfers it to the operating system.

If one of these elements fails, the sensor stops working correctly, for example, if the emitter is clogged, the signal does not pass, and the system "thinks" that there is nothing in front of the screen, so the display does not go out. Or vice versa: if the receiver constantly picks up false signals (due to damage or contamination), the screen will turn off for no reason.

The reason for the error “proximity sensor fail” on Xiaomi

The proximity sensor fail error can occur for a variety of reasons, from simple contamination to serious hardware breakdowns.

Especially often this problem is faced by owners of the following models:

• 📱 Xiaomi Redmi Note 8/8 Pro – the sensor is too close to the edge, often contaminated;
• 📱 Xiaomi Mi A2/A3 — Factory marriages are known;
• 📱 POCO X3 NFC — sensor;
• 📱 Xiaomi Mi 9/9T — Problems after updates MIUI.

⚠️ If the proximity sensor fail error occurs after a phone drop or moisture hits, do not attempt to repair the device yourself - this can short circuit or damage other components.

How to check the operability of the sensor of approach

Before you start repairing, you need to make sure that the problem is really in the proximity sensor, and not something else (for example, a firmware failure or damage to the display plume).

1. Verification through the engineering menu

The most reliable way is to use a hidden engineering menu.

1. Open the phone application;
2. Type the combination: ##6484## (some models may not work, then try ##4636###)
3. Select the Proximity Sensor option.
4. Close the sensor with your hand – the value should change from 5 (no obstacle) to 0 (there is an obstacle).

If the values do not change or the menu does not open, the sensor is faulty.

2. Checking by application

Google Play has tools for testing sensors, such as:

• 📱 Phone Doctor Plus;
• 📱 Sensor Test;
• 📱 CPU-Z (Shows the status of sensors in the Sensors section).

If the app app approximation sensor is displayed as Not available or shows incorrect values – the problem is confirmed.

3. Visual examination

Take a closer look at the top of the screen:

• 🔍 Are there any cracks or chips on the glass above the sensor?
• 🔍 Did not get dirt or moisture under the protective glass?
• 🔍 Has the protective film unstuck (if it was pasted carelessly, it can block the IR signal)?

⚠️ Attention! If you have recently changed a display or protective glass, the problem may be in the wrong installation, for example, if the glass is glued with a gap or used a poor-quality glue, this can block the sensor signal.

How to fix the proximity sensor fail error

If the sensor is physically functional but not working properly, the problem may be in the software.

1. Phone reboot

Sometimes a simple reboot helps to reset the temporary errors in the sensor.

• Press the power button;
• Select Reboot;
• After turning on, check the sensor.

2. Resetting settings to factory

If the problem occurs after updating or installing applications, resetting can help. Important! pre-backup data, as all files will be deleted.

How to reset:

1. Go to Settings → About the phone → Reset settings;
2. Choose Reset all settings;
3. Confirm the action.

3. Update or roll back firmware

If the error is close sensor fail after the update MIUI, try:

• 🔄 Update to the latest firmware version (maybe the bug has already been fixed);
• 🔙 Reverse to the previous stable version (if you know the sensor was working normally).

To roll back the firmware, you will need to unlock the bootloader and use the Mi Flash Tool. This is a risky procedure - if you are not sure of your abilities, you should consult a specialist.

Sensor calibration (for some models)

On some Xiaomi smartphones, you can manually calibrate the proximity sensor.

1. Enter the code in the phone application: ##6484##;
2. Select Proximity Sensor Calibration.
3. Follow the instructions on the screen.

If there is no such item, your model does not support calibration.

💡

Before resetting settings or firmware, check if you have a developer mode with debugging on USB. Sometimes this interferes with the correct operation of sensors.

Repair of the proximity sensor with their own hands

If the software methods didn't work, it's probably a hardware problem, and in some cases, you can try to repair the sensor yourself, but it's risky, because the wrong actions can completely disable the phone.

1. Cleaning the sensor

If the problem is contamination, try to clean the sensor area carefully:

• 🧹 Use a soft brush or cotton swab soaked in alcohol;
• 🚫 Don’t press hard – you can damage the IR diodes;
• 🔍 Check if the dirt has fallen under the glass (in this case, disassembly will be required).

Replacement of protective glass

If the sensor stopped working after the glass was stickered, the problem may be:

• 📏 Incorrect cutout under the sensor (it should be opened);
• 💧 Use of poor-quality glue that blocks the IR signal;
• 🔨 Damage to the sensor during installation.

The solution is to gently remove the glass and paste a new one, making sure the sensor area is not closed.

Replacement of the proximity sensor

If the sensor is physically damaged, it's going to have to be replaced.

• 🔧 Set of screwdrivers (star, cross);
• 🔥 Hair dryer or glue heating station;
• 🛠️ Plastic blades for disassembly;
• 📦 New sensor (can be ordered on AliExpress or in service centers).

Step-by-step:

1. Turn off the phone and remove the back cover (heating with a dryer);
2. Disconnect the battery;
3. Find the proximity sensor plume (usually it goes along with the front camera plume);
4. Carefully disconnect the old sensor and install a new one.
5. Put the phone back together.

⚠️ Attention! Replacing the proximity sensor requires experience in electronics repair. If you've never disassembled a smartphone, you'd better trust the professionals to do it - an assembly error can damage the motherboard.

When to contact the service center

Not all breakdowns can be repaired by yourself.

• 🔧 You took your phone apart but couldn’t find the cause of the malfunction;
• 💥 The sensor stopped working after falling or getting moisture;
• 🔌 After the sensor was replaced, the problem remained (maybe the motherboard was damaged);
• 📉 The phone is under warranty (self-repair will deprive you of warranty service).

The cost of repair in the service depends on the model and nature of the breakdown:

Before you bring your phone to the service, specify:

• 🔍 Do they have original parts for your model;
• 📋 Do they give a guarantee for repairs;
• 💰 How much will the diagnosis cost (sometimes it is free).

💡

If your Xiaomi is warranty-free, don't disassemble it yourself! Opening the case will void warranty obligations.

How to temporarily bypass the problem with the proximity sensor

If repairs are delayed and you need to use your phone now, you can temporarily turn off the sensor or adjust it manually.

1. Disconnect the sensor through settings

In some firmware MIUI You can turn off the screen response to the proximity sensor:

1. Go to Settings. → System applications → Phone;
2. Find the option of Approach Sensor or Automatic Screen Shutdown;
3. Turn it off.

Cons: During the call, the screen will not lock and you may accidentally press the buttons with your cheek.

2.Use of applications to force the screen to turn off

Google Play has utilities that allow you to manually lock the screen during a call, for example:

• 📱 Proximity Sensor Fix;
• 📱 Screen Off and Lock;
• 📱 Gravity Screen.

3. Customization of gestures

On some Xiaomi models, you can set up a gesture to lock the screen, for example:

• Double touch on the screen;
• shaking of the phone;
• Press the power button.

This won’t solve the problem completely, but it will make the phone more comfortable.

Frequently Asked Questions (FAQ)