The fingerprint scanner on Xiaomi smartphones is one of the most convenient ways to unlock, but sometimes it suddenly stops working, with users experiencing errors such as “Impactless to recognize the fingerprint”, “Sensor is not responding” or completely ignoring touch. In 80% of cases, the problem can be solved independently without going to the service center, and in this article we will discuss all possible causes, from banal contamination of the sensor to serious hardware malfunctions, and also give step-by-step instructions for restoring the scanner on Redmi models, POCO mi.
It's important to understand that the sensor's algorithm depends on the type of sensor: optical (under the screen), ultrasonic (like the Mi 10 Ultra) and capacitive (physical button on older models), each with its own weak spots. For example, optical scanners often suffer from scratches on the screen, and ultrasonic scanners from firmware updates. We'll look at solutions for all types, and we'll also tell you when to hit the alarm and carry the phone for repair.
If your Xiaomi has stopped recognizing fingerprints after a fall, updates MIUI Or changing the windows is a signal of different problems. Don't rush to reset the settings to the factory: in 60% of cases, simple manipulations that take no more than 5 minutes help.
1. Pollution of the sensor or screen
The most common cause of failure is dust, grease, or moisture on the scanner surface. Optical sensors (built into the screen) are particularly sensitive to this: even a thin layer of pollution can block infrared radiation. Capacitive sensors (physical buttons) are less susceptible to this, but also require cleanliness.
How to check:
- 🔍 Inspect the sensor area for visible spots, scratches, or moisture.
- 📱 If the scanner is under the screen, check if there is a protective film or glass with defects on the display.
- 💧 Try to recognize the fingerprint with a dry finger (wet or sweaty fingers often knock the sensor down).
How to clean:
- Turn off the phone and gently wipe the sensor area with soft lilac-free cloth (such as microfiber for glasses).
- For persistent contaminants, use isopropyl alcohol (70% or higher) - apply a few drops to the fabric and wipe the surface. Don't pour alcohol directly onto the phone!
- If the sensor is under the screen, clean the entire display, as contamination at the edges can also interfere.
💡
To clean the sensor DO NOT use wet wipes, paper towels or abrasive materials – they can leave micro scratches that will permanently spoil the scanner.
After cleaning, restart your phone and try adding a fingerprint again. If the problem persists, move on to the next item.
Damage to the sensor or screen
Physical damage is the second most common cause of a scanner that fails, and even a minor fall or impact can displace the sensor, damage its contacts, or disrupt the integrity of the screen (if the scanner is built in). 10T Pro or Redmi K40 Pro+), wherein the sensitive element is located under the glass.
Signs of hardware malfunction:
- 🚨 The scanner does not respond at all (there is no vibration or backlight when touched).
- 🔧 On the screen around the sensor area appeared cracks or chips.
- 🔄 The fingerprint is recognized only at a certain angle or with a strong press.
- 💥 The phone fell or was subjected to severe vibration (for example, in a backpack without a cover).
How to diagnose:
- Try adding a new fingerprint – if the process ends up with an error in the scanning phase, the problem is more hardware.
- Run the Equipment Test through the Engineering Menu: ##4636## → "Testing of equipment" → "Fingerprint Sensor If the test shows an error, the sensor is defective.
- Check if the vibration is working when you touch the sensor, and if it's not, you might have a plume break.
What to do if the sensor is physically damaged?
If there is no damage, but the scanner still does not work, the problem may be in the software.
3. Failures after MIUI update
Firmware updates MIUI And it's often not just new features, but it's also bugs, and one of the most common is the broken fingerprint sensor after the update, which is caused by driver conflicts, changes in recognition algorithms, or errors in the kernel, and it's especially true for models. POCO F3, Redmi Note 10 Pro and Xiaomi 11T, where the scanner is integrated into the screen.
Signs of software failure:
- 🔄 The sensor worked before the update, and then stopped.
- 📱 In the settings, the fingerprint is added, but not recognized when unlocked.
- 🔧 A message appears “Update the sensor firmware” (although no updates are available).
- 🛠️ In the system logs (via adb logcat) errors such as FingerprintHal: timeout are visible.
How to fix it:
- Restart your phone – sometimes it resets temporary driver errors.
- Clear the sensor cache: Go to Settings → Annexes → Application management. Find the fingerprint sensor (or BiometricService). Press Clear cache and Reset settings.
- Update rollback (if the problem has occurred after the last update): Go to Settings → The phone. → Update the system. Click on the icon. ⚙️ (gear) → Remove the latest update. ⚠️ Note: This option is only available for 10 days after the update!
- Reset sensor settings: Remove all saved prints in Settings → Passwords and security. Reset your phone. Add the fingerprint again, following the instructions on the screen.
If the reset didn’t help, try manually updating the sensor firmware (relevant for models with a separate scanner chip, such as the Redmi Note 9 Pro).
- Download the latest firmware version for your model from the official Xiaomi website.
- Go to Settings → About Phone → System Update → Three Dots (menu) → Select a firmware file.
- Select the downloaded file and wait for the installation to be completed.
4. Conflict with protective glass or film
Many users install protective glass or film on Xiaomi without thinking that it can block the scanner, especially for models with an integrated optical sensor (for example, Xiaomi Mi 11, POCO X3 Pro, where recognition requires direct contact of the finger with the glass, even a micron gap or air bubbles can render the scanner inoperable.
How to check:
- 🔍 Remove the protective glass/film and try to recognize the fingerprint.
- 📱 Illuminate the flashlight on the sensor area – if you see iridescent smears or distortions, the glass is installed incorrectly.
- 💡 Check if there is a cutout for the sensor on the glass (on some models it is mandatory).
Decisions:
| Problem. | Reason. | Decision |
|---|---|---|
| The scanner is not responding. | Glass too thick or with air | Replace with a glass with a sensor cutout (for example, Spigen Neo Flex for Redmi Note 11) |
| It only recognizes 3-5 attempts. | Matte-surface film | Use a glossy film or glass with oleophobic coating |
| Sensor locked error | Metallized glass | Install regular tempered glass without additional coatings |
| It only works when pressed hard. | Bubble film over the sensor | Plug the film, paying attention to the scanner area |
If you just changed the glass and the scanner stopped working, it's probably a bad installation, so try re-gluing it or contacting the service where you replaced it, which is 90 percent of the time.
💡
On Xiaomi models with built-in scanner (for example, Mi). 10T, Redmi K50) You can not use glass with full screen coverage - a cutout for the sensor is required!
5. Failures in security settings
Sometimes the fingerprint sensor will stop working due to conflicts in security settings or failures in the BiometricService service.
- 🔒 Installations of third-party launchers or such.
- 📱 Activation of the developer mode with changing the animation settings.
- 🔧 Use of cache cleaning applications (e.g. Clean Master).
- 🛠️ Manually delete system files via Root.
How to restore work:
Turn off the developer mode (if enabled)
Remove all third-party launchers and themes
Reset the application settings (Settings) → Annexes → Application management → Three points. → Reset the settings)
Check if BiometricService is disabled in Settings → Annexes → All applications
-->
If the sensor is still not working, try resetting the security settings:
- Go to Settings → Passwords and Security → Fingerprint Sensor.
- Delete all the fingerprints you saved.
- Go back to the main settings menu and select the System → Resetting settings → Resetting security settings.
- ⚠️ Attention: This will remove everything PIN-codes, graphics keys and Mi Account data from your device. Make sure you remember your Xiaomi account password in advance!
After reset, add the print again, and if there was a software conflict, the scanner will go live.
6. Problems with the firmware or core of the system
In rare cases, the fingerprint sensor stops working due to serious firmware errors, for example:
- 🔧 Damage to files /system/bin/fingerprintd or /vendor/lib64/hw/fingerprint.
- 📱 Incompatibility of the kernel with sensor drivers (relevant after manual update via Fastboot).
- 🔄 Conflict after rollback to the old version MIUI.
How to diagnose:
- Check the logs of the system through adb logcat | grep -i If you see errors like FingerprintManager: service died, the problem is the firmware.
- Install the Device Info app and check the Hardware section → Biometric sensors. If the sensor is not displayed, the driver is not loaded.
Decisions:
- Fastboot: Download the official firmware for your model from Xiaomi Firmware. Unpack the archive and launch the script flash_all.bat (for Windows or flash_all.sh (for Linux/Mac). ⚠️ Warning: This will completely erase all the data on the phone.
- Update the sensor driver manually (for advanced users): Download the fingerprint.ko file for your model (look for the forums) XDA Developers or 4PDA). Put him in. /vendor/lib/modules/ through ADB Or Root Explorer. Run the commands: su chmod 644 /vendor/lib/modules/fingerprint.ko insmod /vendor/lib/modules/fingerprint.ko
If after flashing the sensor still does not work, and in the logs there is a Fingerprint error HAL: probe failed is a sign of hardware malfunction (a sensor chip or a plume is damaged), in which case only repair will help.
7. When to contact the service center
If you’ve tried all the ways, but the fingerprint sensor on Xiaomi still doesn’t work, it’s probably a hardware problem.
- 🔧 Sensor not detected in Equipment Test (#4636##).
- 💥 The phone fell into the water or was subjected to a strong vibration.
- 🔄 After the screen was replaced, the scanner stopped working (possibly damaged plume).
- 📱 On the screen, cracks or severances are visible in the sensor area (for optical scanners).
- 🔌 When connecting to a PC through ADB Adb shell dumpsys fingerprint returns Service not found.
Cost of repair:
| Type of breakdown | Cost (₽) | Duration of repairs |
|---|---|---|
| Replacement of sensor plume | 1 200 — 2 500 | 1-2 hours |
| Replacement of the capacitive sensor (button) | 1 500 — 3 000 | 1 day |
| Replacement of the optical sensor (under the screen) | 3 000 — 6 000 | 2-3 days |
| Replacement of the display with scanner | 5 000 — 12 000 | 3-5 days |
Before the service visit:
- Make a backup of your data (via Mi Cloud or ADB backup).
- Find out if the model has a warranty (if so, repairs can be free).
- Check out the reviews about the service center – some workshops use non-original spare parts.
💡
If your Xiaomi is guaranteed, DO NOT open it yourself! This will void the warranty. Contact the official Xiaomi service center or an authorized partner.