How to check the sensor on the smartphone Xiaomi: from diagnosis to repair

Touch screen is one of the most vulnerable elements of Xiaomi smartphone, and its malfunctions can manifest in different ways: from random "ghost" touches to complete ignoring commands, POCO Or Mi stopped responding to touch, don't rush to take it to the service center, and 80 percent of the time, you can diagnose the problem yourself, because you need to know the right testing methods and be able to interpret the results.

In this article, we’ll break down 5 proven ways to check touchscreen on Xiaomi devices, including hidden engineering menus, specialized applications, and hardware tests. You will learn how to distinguish between a software failure and a physical failure, which errors are critical and which can be fixed without changing the screen. AMOLED-displays (for example, Xiaomi 13 Pro or Redmi) K60), where sensor problems are often associated with improper operation of the digitizer layer.

Before you start diagnosing, make sure that the problem is not in the protective film or the case - sometimes they can block some of the touches. Also check if the Glove mode is activated in the settings (it increases sensitivity, but can cause false positives). If the screen responds only to a strong press, it may be a worn plume or a departed connector.

1. Built-in sensor test in Xiaomi's engineering menu

All Xiaomi smartphones (including the budget Redmi Note and the flagship Mi) have a hidden engineering menu with tools for diagnosing hardware components. To get there, you do not need root rights or special applications – just know the right combination.

Instructions for calling the sensor test:

1. Open the Phone app.
2. Enter the combination: ##6484###
3. The Manual Test menu will appear on the screen – select Touch Screen Test.
4. Follow the instructions on the screen: swipe your finger through all the designated areas.

This menu displays touch coordinates (X and Y) and response times. If the lines are drawn with a delay or miss individual points, this indicates a malfunction of the digitizer layer or damage to the plume. On models with a high frequency of sensor survey (for example, POCO F5 Pro with 240 Hz) test can show false positives - it's normal if they don't repeat systemically.

✅ Sensitivity to touches throughout the screen

✅ Correctness of coordinate display (no "jumping" points)

✅ No "dead" zones (usually around the edges)

✅ Response time (should be) ≤ 100 ms)

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Please note: on some firmware (for example, MIUI Global 14) the engineering menu can be blocked, in which case use an alternative code:

##4636##

Hardware Testing

Touch Test

2. Diagnostics through the application "Equipment Test" (MIUI)

If the engineering menu is not available or its data seems insufficient, use the standard hardware test application, which is pre-installed on all Xiaomi smartphones, which allows you to check not only the sensor, but also other components (speaker, microphone, cameras), which is useful for complex analysis.

How to run the test:

• 📱 Open the Settings. → The phone. → Press 5 times on the version MIUI, activate the developer mode.
• 🔧 Return to the main settings and select Additional → Hardware test.
• 👆 Scroll through to the Touch Panel Test section and click Start.
• 📊 Follow the hints on the screen: swipe your finger on all the lines and points indicated.

The app gives a detailed report showing the number of missed touches and the average response time.

If the test shows errors in the top or bottom of the screen, this may indicate that the plume is detached (a common problem after falls). On models with curved screens (for example, Xiaomi Mix 4), uneven sensitivity at the edges is normal if it does not exceed 10%.

Once a month

Only when problems arise

Never checked.

After every fall-->

3.Use of third-party applications for deep diagnostics

Standard tools MIUI They don't always give a full picture, especially if the problem is recurring, and Google Play's specialized apps that offer advanced tests, including multi-touch, pressure, and even temperature zones, will help.

Top.-3 Applications for testing the sensor on Xiaomi:

• 🔍 Touch Screen Test — checks all areas of the screen, builds a heat map of sensitivity, suitable for detecting dead pixels in the touch layer.
• 📊 MultiTouch Tester – Tests multi-touch support (up to 10 fingers at a time) useful for gamers and owners POCO F-series with high frequency survey.
• 🛠️ Phone Doctor Plus is a comprehensive test of all sensors, including sensor, accelerometer and gyroscope.

Example of MultiTouch Tester:

1. Install the application and open it.
2. Select Advanced Test mode.
3. Touch the screen with several fingers at the same time (e.g. 5-10).
4. See if all the points are displayed correctly, if there are "stick" touches.

If the app shows that the smartphone recognizes fewer fingers than stated in the specification (for example, 5 instead of 10 on Xiaomi) 12T Pro, this may indicate a sensor controller problem or a plume damage. Also note the color tags on the heat map: red zones indicate too high sensitivity (false positives are possible), blue zones indicate low (missed touches).

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If the test shows unstable multi-touch operation, try calibrating the sensor through the engineering menu (code # #36446337##). MIUI.

4. Checking the sensor through ADB (for advanced users)

If standard methods do not give a definite result, you can use Android Debug Bridge (ADB) This method requires connecting the smartphone to a PC, but it allows you to get data that is not available through conventional tests, for example, raw values from a touch controller.

Instructions for checking through ADB:

1. Install ADB Tools on your computer.
2. Activate Debugging on USB on a smartphone: Settings → The phone. → Version. MIUI (press 7 times) → For developers → Debugging by USB.
3. Connect your phone to your PC and type in the command line: adb shell getevent -l
4. Touch the screen – events with coordinates and pressure will appear in the log (parameter). PRESSURE).

Analyzing the conclusion, pay attention to:

• 📍 Coordinates: If they jump when statically touched, the problem is the controller.
• ⚖️ Pressure: value PRESSURE=0 when pressed indicates a sensor malfunction.
• ⏱️ Delays: if between events ACTION_DOWN and ACTION_UP pass > 200 Ms., there's a lag.

For models with ultrasonic sensor (for example, Xiaomi Mix Fold) 3) The getevent command can output additional parameters such as FINGER_SIZE or TOOL_TYPE. If these values are absent or equal to zero, a malfunction of the hardware part is possible.

5. Hardware check: what to do if the sensor does not respond at all

If the Xiaomi screen completely ignores touch (even unlocking doesn’t work), but the image is displayed, the problem may lie in:

• 🔌 Disconnected plume (frequent cause after falls).
• 🔋 Faulty sensor controller (requires motherboard replacement).
• 🌡️ Overheating (the sensor can be turned off at temperature) > 60°C).
• 🔄 Software failure (for example, after a failed update).

Algorithm of actions for hardware diagnostics:

1. Check the plume: If the phone falls, disassemble it (or contact the service) and make sure the sensor plume is tightly connected to the motherboard. On Redmi Note 12 and newer models, the plumes are often attached to the latches — they are easy to unplug accidentally.
2. Test with connected mouse: connect OTG-If the cursor is moving and the touching doesn't work, the problem is exactly the sensor or its plume.
3. Checking in Safe Mode: Press the Power button → Safe Mode. If the sensor is up, it's the third-party app's fault.
4. Flashing: If the sensor stopped working after the update, try rolling back to the previous version MIUI via Fastboot.

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If the sensor does not respond to touch, but works with OTG-In 95 percent of cases, a physical defect (a plume or digitizer) is the fault of a mouse.

On models with built-in stylus support (such as the Xiaomi Pad 6), check if the screen responds to the stylus. If so, and your fingers don't, the problem is in the layer responsible for touch recognition (usually the top layer of the screen).

⚠️ Warning: If you notice that the sensor has started to float after getting moisture, immediately turn off the phone and dry it in rice or silica gel for 24-48 hours.

6.Typical sensor errors on Xiaomi and their causes

Not all sensor issues are the same — some point to software failures, others to hardware breakdowns. Below, we’ve collected the most common symptoms and their possible causes for Xiaomi devices.

On smartphones Xiaomi with AMOLED-In the case of a screen (e.g. Xiaomi 13 Ultra), there is a frequent problem of "yellow spots" after falls - this is a sign of damage not only to the sensor, but also to the matrix. MIUI, Try resetting to factory settings (Settings) → Additionally. → Resetting settings).

⚠️ Note: If the sensor becomes worse after the screen is replaced in an informal service (for example, dead zones appeared), a non-original digitizer was most likely installed, which often has less sensitivity and fails faster. Check the labeling on the plume – the original Xiaomi parts have a hologram with the brand logo.

7.When to contact the service: signs of critical breakdown

Not all sensor problems can be solved by yourself, but there are a number of symptoms that require professional diagnosis:

• 💥 The screen cracked and the sensor stopped responding to touches at the crack site (even if the image is displayed).
• 🔥 After a fall, the phone overheats, and the sensor shuts down after 5-10 minutes of operation.
• 🔄 Touches are recorded mirror (for example, the tap at the bottom is displayed at the top).
• 🛠️ The sensor only works in a certain position (for example, if you tilt the phone).
• 🔋 The battery is quickly discharged, and the sensor begins to “glutch” at the level of charge. < 20%.

Xiaomi’s service center uses specialized equipment such as an oscilloscope (checks signals from the touch controller) and a thermal imaging device (identifies overheated areas on the board) to diagnose the sensor, the average cost of repairing the sensor in official services:

• Redmi Note 11/12: 3 000–5 000 ₽ (touchscreen).
• Xiaomi 13/14: 8 000–12 000 ₽ (display-module replacement).
• POCO F5 Pro: 6 000–9 000 ₽ (including calibration).

If your smartphone is warranty-free, do not try to repair it yourself - this will void warranty obligations. In case of a warranty failure (for example, if the screen crashed due to your fault), ask the service for a diagnostic report indicating the cause of the breakdown. This will help to avoid fraud when replacing components.

FAQ: Frequent questions about sensor testing on Xiaomi