Where is the proximity sensor on Xiaomi Redmi 9T: location, function and diagnosis

The proximity sensor in Xiaomi smartphones is a small but critical component that is responsible for automatically turning off the screen during phone calls. 9T (Also known as the Redmi 9 Power in some regions, this sensor is often the subject of questions from users, especially when the screen does not go out when the device is held to the ear or, conversely, does not turn on after the call is completed. In this article, we will analyze exactly where the proximity sensor on Redmi is located. 9T, How it works and what to do if it starts to fail.

Many people mistakenly think that the proximity sensor is a separate physical module that can be easily replaced. 9T It's integrated into the top of the display module and is closely linked to the front camera and speaker, which means that when the sensor is damaged, it often requires the entire screen to be replaced, rather than the individual element. We will also tell you how to check its performance without disassembling the phone and what software settings can affect its correct operation.

Where is the proximity sensor on Xiaomi Redmi 9T: physical location

On the Xiaomi Redmi model 9T The proximity sensor is located in the upper right corner of the front panel, next to the front camera and the light sensor, and it is visually impossible to see with the naked eye, because it is hidden under the screen glass and is a miniature infrared sensor. If you look at the top frame of the display, you can see a small darkened spot - this is a protective coating of the sensor.

It's important to understand that the proximity sensor works in tandem with software that analyzes the signals from the sensor. 9T infrared (IR) A sensor that emits invisible light and picks up the reflection from objects near the screen, and when you hold the phone to your ear, the sensor picks up the obstacle and sends a signal to the system to turn off the backlight of the display.

• 📍 Exact location: upper right corner, under the screen glass, next to the front camera.
• 🔍 What it looks like: a small darkened spot (size) ~2 mm) on the black display frame.
• 🛠️ Feature: Integrated into the display module, not replaced separately.

If you try to disassemble the phone to get to the sensor, you'll find that it's soldered to the flexible plume of the display. That's one of the reasons why the proximity sensor repair on Redmi is so important. 9T It is often unprofitable – it is easier to replace the entire screen than to try to restore the work of one microscopic element.

How the proximity sensor works: the principle of operation and communication with the software

Approximate sensor in Xiaomi Redmi 9T It works in a simple but effective way, and it emits an infrared beam and analyzes the reflection of the infrared beam, and when you hold the phone to your ear, the beam bounces off the surface and back to the sensor. The system interprets this as an “obstacle” and commands the screen to shut down to prevent accidental taps during a conversation.

But the sensors are not just dependent on the hardware, but also on the software algorithms. MIUI There are certain sensitivity parameters that can vary depending on the software version, for example, after updating the system, some users notice that the sensor has become delayed or, conversely, too abrupt. This is due to a change in the logic of signal processing from the sensor.

Interestingly, in some cases, the proximity sensor can conflict with protective glasses or covers, for example, if the glass is metallized or too thick, it can block the infrared signal, which causes the sensor to stop working correctly, the same applies to cases with high sides that physically overlap the area of the sensor.

⚠️ Warning: If you recently put on a new security glass and notice problems with the proximity sensor, try temporarily removing it and testing the phone. In 30% of cases, this is how the problem is solved.

How to check the proximity sensor on Xiaomi Redmi 9T: step-by-step

Before you take your phone to the service center, you can check the operability of the proximity sensor yourself. MIUI We'll describe both methods below.

Method 1: Use of the Engineering Menu (without root)

The most reliable way to diagnose is the engineering menu, which is available on all Xiaomi smartphones.

1. Open the Phone app.
2. Enter the combination: ##6484### (or #4636## for older versions of MIUI).
3. Select the Hardware Testing option → Sensor.
4. Find the Proximity Sensor list and click on it.
5. Put your hand to the top of the screen, and the value should change from 5 (no obstacle) to 0 (there is an obstacle).

If the values do not change or the sensor shows 0 constantly, this indicates a hardware malfunction. → 0 → 5 without hand-dragging), the problem may be sensor contamination or software failure.

Method 2: Third-party applications (e.g, CPU-Z Sensor Test)

If the engineering menu is not available for some reason, you can use the apps from Google Play:

• 📱 CPU-Z: The sensors show the status of all sensors, including approximations (Sensors section).
• 🔧 Sensor Test: Tests sensors in real time with visualization.
• 🛠️ Phone Doctor Plus: conducts comprehensive diagnostics, including checking the proximity sensor.

Remove the protective glass and case

Wipe the top of the screen with alcohol

Check the values in the engineering menu

Install a third-party application for the test

Reboot your phone before checking-->

If tests show that the sensor does not respond to obstacles, but the phone did not fall or be exposed to moisture, the problem may lie in the software settings. MIUI There is a screen function during the call, which can be manually disabled.

⚠️ Warning: Some "optimizers" and battery-saving applications may block sensors.

Frequent malfunctions of the proximity sensor on Redmi 9T and their causes

In practice, users of Xiaomi Redmi 9T They're facing a few of the typical problems with the proximity sensor. Let's look at the most common ones and their possible causes:

One of the most insidious causes of the malfunction is the ingress of dust or fat into the sensor area, and over time, microparticles accumulate on the surface of the glass that scatter the infrared signal, and the sensor stops correctly detecting the distance to the obstacle, the solution is simple: gently wipe the top of the screen with a cotton swab dipped in alcohol.

Another common problem is damage after a fall, and even if there are no cracks on the screen, the impact could damage the plume connecting the sensor to the motherboard, in which case the screen may work normally, but the proximity sensor will be blind, and you can only diagnose this malfunction in the service center with special equipment.

Software settings affecting the operation of the proximity sensor

Not always problems with the proximity sensor are related to its physical malfunction. MIUI There are a few settings that can affect how it works, like the Screen function at the time of the call allows you to manually turn off the automatic backlighting.

To check and change these settings:

1. Go to Settings → System and device → Additional settings.
2. Select a screen during the call.
3. Make sure that the mode is set Automatically (not Always on or Always off).

You should also pay attention to the settings of special features. → Special facilities → Physical buttons are a screen autoturn option that can indirectly affect sensor performance. If it is disabled, some sensors (including the proximity sensor) may not work properly.

• 🔄 Sensor reset: In the engineering menu (#6484##) you can reset the sensors to factory values.
• 📱 Developer Mode: Enable Debugging by USB and check the error log through ADB, If the sensor is unpredictable.
• 🔧 Cache cleaning: Sometimes it helps to clean the cache of system applications, especially Phone and Settings.

Important: If the proximity sensor stopped working after installing custom firmware (for example, LineageOS or Pixel Experience), the problem lies in the lack of drivers. 9T (codename).

What to do if the proximity sensor is not working: a step-by-step guide

If you are convinced that the proximity sensor on your Xiaomi Redmi 9T Really flawed, follow this algorithm to fix the problem:

Step 1: Programmatic Diagnostics and Resetting

1. Check the sensor through an engineering menu or third-party app (as described above).
2. Reset your phone settings to factory settings (Settings → About Phone → Reset settings).
3. Update your firmware to the latest version (Settings → About Phone → System Update).

Step 2: Mechanical cleaning

If the software methods did not help:

1. Remove the protective glass and cover.
2. Wipe the top of the screen with a cotton swab soaked in isopropyl alcohol.
3. Blow the sensor area with compressed air (for example, a canister for cleaning equipment).

Step 3: Hardware repairs

If the sensor is still not working:

• Contact Xiaomi Service Center for the diagnosis of the plume and display module.
• Check the cost of replacing the screen (as the sensor is not replaced separately).
• If the phone is warranty, repairs should be free (provided the damage is not mechanical).

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If you decide to replace the screen yourself, buy only the original display module for Redmi. 9T (articulation begins with MDY11-...). Cheap analogues often go without a proximity sensor or with incorrect calibration.

⚠️ Don’t try to disassemble your phone without experience – on Redmi 9T It's glued to the body, and if you take it off, you can damage the plume or the battery, and that would lead to additional repair costs.

The cost of repairing the proximity sensor on Xiaomi Redmi 9T

Since the proximity sensor on Redmi 9T It's built into the display module, and you can't replace it separately, which means that if the sensor malfunctions, you'll have to change the entire screen. Below are the estimated prices for repairs in service centers and self-replacement:

The cost depends on several factors:

• 💰 Screen Type: Original modules are more expensive, but guarantee 100% compatibility.
• 🛠️ Difficulty of work: Some services charge an additional fee for gluing glass or checking other components.
• 📅 Urgent: Express repairs can cost 20-30% more.

If you have a Redmi. 9T Official service centers Xiaomi are obliged to fix the malfunction free of charge, if it is not caused by mechanical damage (falls, moisture, etc.). However, keep in mind that the warranty does not cover damage caused by self-repair or installation of non-original parts.

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Before you change the screen, make sure that the problem is in the proximity sensor, not the software settings. In 40% of cases, a simple reset to factory settings helps.

FAQ: Frequently Asked Questions About Xiaomi Redmi Approach Sensor 9T