Modern Xiaomi and Redmi smartphones are complex computing complexes, saturated with a variety of microscopic sensors that provide basic functionality of the device. When the screen stops fading during a conversation or when the image turns when the phone tilts with a delay, it signals the need to conduct a deep diagnostic of the hardware. Checking Xiaomi sensors is not just a test, but often the only way to determine whether the problem lies in the software glitch or if a replacement of the physical module is required.
Device owners often face a situation where, after buying a security glass or falling, the phone begins to behave unpredictably. In most cases, it is early to panic, since the Android system based on MIUI or HyperOS has built-in tools for self-diagnosis. You do not need to immediately carry the gadget to the service center, because the touch screen or approach module can be tested yourself using the hidden capabilities of the operating system.
Next, we'll look at all the ways you can check, from built-in engineering menus to third-party utilities. Understanding how the accelerometer and the light sensor work will help you avoid false diagnoses and save time. It's important to approach the process methodically, checking each component separately to identify the exact element that is causing the malfunction.
Diagnostics through CIT Engineering Menu
The most reliable and in-depth way to test hardware is to use a built-in engineering menu known as the CIT (Customer Inspection Test), which is a section of the system designed for factory testers and allows you to interact with each sensor directly, bypassing standard Android interfaces. To get there, you need to open the Phone app and type in the secret code # # # #6484#, after which a list of all available tests will open.
The CIT interface looks ascetic, but it has a comprehensive list of components. You can check the vibrations, the speakers, the microphones, the Wi-Fi modules, and of course all the sensors. When you pick up the Proximity Sensor, you run a test where you close the top of the screen with your hand and see the change from 5.0 to 0.0, which is the most accurate way to know if the device sees your hand or the safety glass is interfering with your work.
⚠️ Warning: Do not try to change settings in sections that you are not familiar with, especially those marked as "Write" or "Config." Factory calibration resets without special equipment may cause the device to malfunction in the future.
To test the touchscreen, this menu uses the Touchpanel test, and you'll be asked to swipe your finger over all the colored lines on the screen, and if a zone doesn't respond or the line doesn't light up, it indicates a physical defect in the digitizer, and you'll also have the Accelerometer test, where you put your phone on a flat surface and watch the X, Y, Z axes that should be aiming towards zero (or 1G vertically) in the absence of movement.
Checking through standard system settings
If you don't want to mess with the engineering codes, Xiaomi has a friendlier way of initial diagnosis in the standard settings menu, which is less detailed, but allows you to quickly assess the performance of the main sensors without the risk of knocking something down in the system. → The phone. → All options and find the line "Kernel Version" or "Version" MIUI», quick-press 5-7 successively.
And then you'll have a menu that's very similar to CIT, but with a more intuitive interface and colored indicators. You can also run the Sensor test, which combines the gyro, magnetometer and accelerometer checks in one window, and you'll see a virtual cube or bubble that will respond to the tilts of your smartphone, and if the cube gets stuck or moves in jerks, then the gyro needs calibration or repair.
- 📱 Approximation Sensor: Hold your palm to the top of the screen and remove it. The indicator should change color (usually from red to green), signaling the sensor response.
- ☀️ Light Sensor: Cover the top of the display with your hand. Digital light values should drop sharply, and when opened, rise. If the values are still, the sensor is locked or defective.
- 🔄 Gyroscope: Rotate your phone in different directions. The virtual object on the screen should follow your movements without delay and "shaking».
Importantly, this mode also has multi-touch verification, which is critical for gamers, as it allows you to identify dead zones on the screen that are not visible during normal use of the interface. Swipe several fingers simultaneously across the entire display surface to make sure that the capacitive layer is intact and conducts current evenly throughout the area.
☑️ Checklist of the primary inspection
Using third-party applications for testing
When Xiaomi's built-in tools don't seem informative enough, or you want to get real-time graphs and numerical values, specialized applications from Google Play come to the rescue. The leader in this niche is the Sensor Box for Android or AIDA64 app. These snails read raw data from hardware controllers and visualize them, allowing you to see even the slightest deviations in work.
For example, the Sensor Test app will show you a list of all the sensors that are installed in the phone, and if there's no sensor on the list (like a magnetometer), even though it should be, it could mean that the plume has gone off or the module has burned, and these apps also allow you to record logs, which is useful if you plan to go to the service and want to prove to the wizard that there's a problem.
| Title of the annex | Type of sensors to be checked | Advertising | Interface complexity |
|---|---|---|---|
| Sensor Box | All (full spectrum) | There is. | Low. |
| AIDA64 | System and sensors | No (in the base version) | Tall. |
| Test Your Android | Basic sensors | There is. | Medium |
| Phone Check (and fix) | Diagnostics and repairs | There is. | Medium |
The magnetometer is particularly worth checking through third-party software. It's often the case that the navigator is showing the wrong direction, and an app like Magnetic Field Detector helps you figure out if you need calibration. You'll see a magnetic field graph; if it's making noise even far from electronics, there may be magnetized elements in the phone's body or the sensor itself is damaged.
Why can third-party apps lie?
Testing of the proximity and light sensor
The most common problem users face is the incorrect operation of the proximity sensor during calls. The screen either does not go out when you hold the phone to your ear, or, on the contrary, it goes out on its own and does not light up until you complete the call. Before you sound the alarm, it is worth realizing that the infrared sensor can simply be contaminated or blocked.
To begin, carefully wipe the top of the screen, paying attention to the area of the speaker. Often greasy marks, dust or improperly pasted protective glass (especially with a black frame) block the beam. In the CIT engineering menu, select the Proximity Sensor test. Put the phone on the table without touching anything - the value should be 5.0. Close the sensor with your finger - the value should become 0.0. If the values do not change or change chaoticly, calibration is required.
⚠️ Warning: If you use a thick, black-framed protective glass, it can block the light and proximity sensor, and even a good sensor can't work properly.
The light sensor is responsible for autobrightness. If it doesn't work properly, the screen can shine brightly in the dark or be dim in the sun, you can check it by dramatically changing the lighting in the room (turn off / turn on the lights) and watching the numbers in the test menu. A sharp jump in values indicates serviceability. If the chart is smooth and slow, this is a feature of the MIUI algorithms, not a breakdown.
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For forced calibration of the proximity sensor, you can use the application "Proximity Sensor Reset & Test", which resets the sensor settings to factory values without entering the engineering menu.
Diagnosis of accelerometer and gyroscope
The accelerometer and the gyroscope are the vestibular apparatus of your smartphone, and they're responsible for the autorotation of the screen, the pedometer operation, the control of games and navigation. If you notice that the screen doesn't turn when the rotation lock is off or in the navigator you're "looking" in the wrong place, the problem is right here. In the CIT engineering menu, the test is called the Accelerometer.
Put your phone on a perfectly flat horizontal surface. You'll see three axes on the screen: X, Y and Z. At rest, the X and Y axes should be close to 0, and the Z axis should be close to 9.8 (or 1G, depending on the units of measurement). If the values are galloping at rest, you need calibration. In the same menu, there's often a Calibrate button that you press while holding the phone still.
- 🎮 In racing simulators, the car can turn itself if the accelerometer “lies” about the position of the phone in space.
- 🧭 Maps: The gyroscope helps to determine the directions of the world more accurately than GPS. Failure to work will lead to the fact that the direction sector on the map will rotate chaotically.
- 🏃 Health: Shagomer uses accelerometer data to count steps. If it's broken, activity statistics will be wrong.
Sometimes a software reset helps more than calibration. Try turning off the phone completely, wait 10 seconds and turn it on again.If the problem persists after rebooting and calibrating through CIT, there's a high chance of physical damage to the sensor, especially if the phone has recently fallen.
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If the calibration in the engineering menu does not help, and the values of the axes at rest are strongly deviated from the norm (for example, X = 2.0 instead of 0.0), most likely, a replacement of the accelerometer module or the entire board is required.
What to do if sensors fail to be checked
When software recovery methods fail, we need to take more drastic action: If after all the CIT checks, resets and calibrations, the sensors continue to give out an error, the problem is likely hardware in nature, it could be a waste plume, oxidation of contacts after moisture is injected, or the microsensor itself fails.
In some cases, a full Hard Reset helps, but remember that it will delete all your information. Before you try to update the firmware to the latest available version, since Xiaomi often releases patches that fix the sensor drivers. If this does not help, then only the hardware diagnostics at the service center, where the multimeter will check the voltage on the contacts of the sensor.
Don't ignore faulty sensors, especially the proximity sensor. A constantly burning screen during a conversation can lead to occasional cheek presses (sending messages, resetting calls) and increased battery consumption. In addition, a faulty light sensor can quickly land the battery, keeping the backlight at maximum.