Fingerprint scanner on Xiaomi does not work: reasons and solutions

The fingerprint scanner on Xiaomi smartphones is one of the most convenient ways to unlock, but sometimes it stops working. Users face problems: the sensor does not respond to touch, gives an error “I could not read the fingerprint”, or the phone does not recognize registered fingers at all. The reasons can be both software (software failure, update conflict) and hardware (sensor damage, pollution).

In this article, we will look at all possible causes of a faulty fingerprint scanner on Xiaomi (including the Redmi, POCO, Mi models) and give step-by-step instructions for their elimination – from a simple reboot to complex firmware manipulations.

1. Check basic settings and reboot

Before you start complex manipulations, make sure that the problem is not caused by a temporary system failure.

• 🔄 Reboot the phone. Long press on the power button. → Reboot. It'll reset the temporary OS bugs that could have blocked the sensor.
• 🔒 Check the scanner activation. Go to Settings. → Passwords and security → Fingerprint and make sure the function is enabled.
• 📱 Make sure the screen is clean. Fat marks or protective film may interfere with reading (especially on sensors under the screen).

If the sensor is running after the reboot, the problem was temporary. If not, move on to the next step.

⚠️ Note: Some Xiaomi models (e.g. Redmi Note 10 Pro) after the update MIUI The fingerprint scanner may be disabled due to a failure in the com.android.biometrics service, in which case the reset of security settings will help (see section 4).

Cleaning the sensor and checking for physical damage

Sensor contamination is one of the most common causes of malfunction, especially for ultrasonic scanners (e.g., Xiaomi Mi 11 Ultra) and optical sensors under the screen (Redmi K40 series, POCO F4).

How to properly clean the sensor:

1. Turn off the phone.
2. Take a soft lilaless napkin (for example, for glasses) and slightly moisten it with isopropyl alcohol (70% and above).
3. Gently wipe the sensor area (on the back or under the screen) without pressing.
4. Let the phone dry 2-3 minutes before turning on.

If the sensor is physically damaged (cracks, dents, traces of oxidation), self-repair is impossible - you need to replace the module in the service center.

• 🚨 The sensor does not glow (for optical scanners under the screen).
• 🔍 The phone doesn't respond to any prints, even after being reset.
• 💥 Artifacts appeared on the screen around the scan area (for sensors in the display).

3. Removal and re-registration of fingerprints

Sometimes the problem is the damaged fingerprint data, so delete all your saved fingers and re-register them.

1. Go to Settings → Passwords and Security → Fingerprint.
2. Enter. PIN-code or pattern lock for confirmation.
3. Delete all saved prints (click on each and select Delete).
4. Register the print again by following the instructions on the screen.

Tips for successful registration:

• 👆 Raise and lower your finger smoothly without pressing too hard.
• 🔄 Register the same finger multiple times at different angles for better recognition.
• 🚫 Do not use wet or dirty fingers.

If the scanner still doesn’t work after re-registration, the problem may be system settings or firmware.

4.Reset security settings and cache

A failure in biometrics services (com.android.biometrics) or cache accumulation can block the sensor from working.

1. Open Settings → About the phone → All settings (or additionally).
2. Find Reset security settings (on some firmware - Reset Face ID and fingerprints).
3. Confirm the action. PIN-code.
4. Reboot the phone.

If this doesn’t help, clear the cache of system applications:

1. Go to Settings → Applications → Application Management.
2. Find Settings (or BiometricService) and select Clear Cache.
3. Repeat for Google Play Services (sometimes conflicting with MIUI).

⚠️ Note: On some Xiaomi models (e.g, POCO X3 Pro) resetting security settings also deletes Mi Account and Google Smart Lock data.

5. Update firmware and roll back to stable version

The scanner's malfunctions are often due to MIUI updates, for example, after the release of MIUI 14, many Redmi Note 11 users complained about a broken sensor due to bugs in the biometric drivers.

• 🔄 Update the firmware to the latest version: Settings → The phone. → Updating the system.
• 📉 If the problem occurs after the update, roll back to the stable version via Fastboot or Recovery.
• 🛠️ Install custom recovery (for example, TWRP) and sew clean MIUI no-bloatware.

Critical information: On models with a sensor in the power button (for example, Redmi) 9A) Firmware rollback can cause the scanner to fail completely due to a change in encryption protocols. EDL-service-centre.

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If the scanner is unstable after the upgrade, try turning off the "Unlock When Uplift" function in the lock screen settings. It may conflict with the sensor.

6.Verification for viruses and conflicting applications

Viruses or applications with administrator privileges can block access to biometric data.

1. Install Malwarebytes or Dr.Web Light and scan the system.
2. Go to Settings → Applications → Special Access → Device administrators and disable permissions for suspicious programs.
3. Check the list of applications with access to Usage Access (Settings → Applications → Permissions → Special Access).

Some applications may conflict with the scanner:

• 🔒 Password Managers (e.g. LastPass, 1Password).
• 🛡️ Antiviruses with biometric blocking function (e.g. Avast).
• 🎮 Cheater utilities for games (can modify system files).

If you suspect a particular app, remove it and check the sensor in safe mode:

1. Press the power button → long press on Turn off → Safe mode.
2. Try adding a fingerprint in safe mode.

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If the scanner is running in safe mode, the problem is exactly with third-party software. Uninstall recently installed applications or reset to factory settings.

7. Hardware malfunctions and service repairs

If none of the software methods worked, the problem is probably hardware.

• 🔌 The sensor plume has gone (often after a fall or disassembly of the phone).
• 🔋 Damaged biometrics controller on the motherboard.
• 💧 Oxidation of contacts due to moisture.
• 🔍 Failure of the sensor itself (especially relevant for older models).

When to contact the service:

• 🛠️ The phone fell or came into contact with water.
• 🔧 The sensor does not work even after a complete reset.
• 📱 Artifacts appear on the screen when you try to scan.

The cost of repair depends on the model:

• Sensor plume replacement: 800–1500 ₽.
• Replacement of the sensor itself: 1500–3000 ₽ (more expensive).
• Maintenance of the motherboard: from 3000 ₽.

⚠️ Note: On models with a sensor in the display (for example, Xiaomi 12 Pro), self-replacement of the screen often leads to the inoperability of the scanner.

FAQ: Frequent questions about the fingerprint scanner on Xiaomi