Xiaomi fingerprint scanner does not work: all the reasons and ways to fix

The fingerprint scanner on Xiaomi smartphones is one of the most convenient ways to unlock, but sometimes it stops working for no apparent reason. The device does not recognize the fingerprint the first time, the sensor does not respond to touch at all, then after the system update, the function disappears completely, and in 80% of cases, the problem can be solved independently without going to the service center.

In this article, we will discuss all possible reasons why the fingerprint scanner on Xiaomi does not work, from the banal (mud under glass) to the technical (damage to the plume or firmware failure). For each reason, we will give step-by-step instructions for elimination, including hidden settings. MIUI, team ADB We'll focus on the nuances for popular models: Redmi Note. 10/11/12, POCO X3/X4/X5, Mi 11/12/13 Xiaomi 13T/14.

If you’ve tried rebooting your phone or resetting your sensor settings, skip the first two sections and jump straight to hardware problems or crashes. MIUI. For owners of flagships with ultrasonic scanner (for example, Xiaomi 13 Ultra) added a separate unit with unique recommendations.

Top.-5 Reasons Why Xiaomi’s Fingerprint Scanner Doesn’t Work

Let's start with the most common problems that users solve in 5-10 minutes, check them in order before digging deeper:

  • 🧼 Sensor or glass contamination: Sweat, dust, residues from a cream or protective film block the reading of a fingerprint, especially for models with an optical scanner under the screen (e.g., Redmi Note 11 Pro).+).
  • 🔄 Software failure. MIUI May “forget” saved prints after an update or sudden power outage.
  • 📱 Damaged security glass or film, cracks or bubbles over the sensor distort the signal, especially in ultrasonic scanners (e.g. Xiaomi). 12S Ultra).
  • 🔋 Battery savings: In Ultra Battery Saver mode or low charge (less than 5%), the sensor automatically shuts down.
  • 🛠️ Mechanical damage: Falling the phone or getting moisture can damage the sensor plume (a common problem in the body). POCO F3/F4 post-disassembly).

If none of these are suitable, move on to the following sections, and for convenience, we have compiled a table with typical symptoms and solutions:

Symptoms.Probable causeDecision
Sensor does not respond to touchPollution, software failure, plume damageCleaning, rebooting, plume check
Identifies the fingerprint only with 5-10 attemptsPoor quality of recorded print, wear of sensorRewrite the print, replace the sensor
The function disappeared after the MIUI updateFirmware failure, module conflictReset sensor settings, rollback update
The scanner is working, but unlocking is not working.Conflict with security applications (e.g. Google Smart Lock)Disable third-party unlock services
Sensor warms or squeaksShort circuit, damage to the controllerDiagnostics in the service, replacement of the module

⚠️ Attention: If the scanner stopped working after falling into the water or replacing the battery yourself, do not try to disassemble the device yourself. In 90% of cases, this damages the flexible plume of the sensor, and it will have to be changed completely.

📊 What Type of Fingerprint Scanner Does Your Xiaomi Have?
Optical (under the screen)
Capacitive (button)
Ultrasonic.
I don't know.

Software Solutions: From Reboot to Reset MIUI

In 60 percent of cases, the problem is solved at the software level, starting with the simplest steps and gradually moving on to the more radical ones.

1. Phone reboot

It's trivial, but it works: Holding the power button for a long time (10-15 seconds) before turning it off and re-energizing it resets the sensor's temporary errors. If the phone freezes, use the forced reboot:

  • For most models: Power button + Loudness up (hold 10-20 seconds).
  • For Xiaomi. 12/13/14: Power button + Loudness down.

2. Sensor data cleanup

The scanner malfunction may be due to the damage to the fingerprint files, so that you can reset them:

  1. Go to Settings → Passwords and Security → Fingerprint.
  2. Delete all the fingerprints you saved.
  3. Reboot the phone.
  4. Add the print again by following the instructions on the screen.

Important: When adding a fingerprint, do not use wet or dirty fingers, this will lead to recognition errors. For best results, write the same finger 2-3 times at different angles.

3. Resetting security settings

If cleaning fingerprints didn’t help, reset all security settings (this won’t delete data, but will require re-configuring unlock):

  1. Open Settings → About the phone → Reset settings.
  2. Select Reset Security Settings (or Reset Lock Settings on Older Versions) MIUI).
  3. Confirm the action with a password.

⚠️ Note: On some models (POCO X3 Pro, Redmi 9T) Resetting security settings also deletes Mi Account data. Before the procedure, make sure to remember the username and password from the Xiaomi account, otherwise you risk blocking the phone!

4.Update or rollback MIUI

If the scanner stopped working after the system update, try:

  • 🔄 Update to the latest version MIUI (Maybe the bug has already been fixed).
  • 📉 Reverse to the previous firmware (if the problem appeared after the update:
  1. Download the necessary firmware version from the official Xiaomi website.
  2. Go to Settings. → The phone. → Updating the system → Threefold (⋮) → Select a firmware file.
  3. Install the downloaded file and restart the phone.

Make sure that the battery charge is > 50%

Download the firmware for your model

Make a backup copy of the data

Disable the lockdown OEM (developer-setting)

Know the username/password from Mi Account-->

Hardware problems: from pollution to sensor replacement

If the software methods didn't work, the problem is the hardware. Let's look at the typical hardware malfunctions and how to fix them.

1. Cleaning the sensor and glass

Optical and ultrasonic scanners are particularly sensitive to contamination.

  • 🧴 Use an alcohol wipe (70% isopropyl alcohol) or a special liquid to clean the screens.
  • 🧻 Gently wipe the sensor area with a soft lintless cloth (microfibra).
  • 🚫 Do not use abrasive materials, paper wipes or harsh chemicals (acetone, gasoline).

For models with a scanner in the power button (Redmi Note) 8/9, POCO M3) Check if the button's mechanism is clogged with dust, and if the button is pressed tightly, it can block the sensor from working.

2. Checking of protective glass or film

Poor glass or improperly pasted film can block the scanner signal, especially for:

  • 📱 Xiaomi with an optical scanner under the screen (Mi 11, Redmi) K40).
  • 🔊 Models with ultrasonic sensor (Xiaomi 13 Ultra, Mix 4).

How to check:

  1. Remove the protective glass/film.
  2. Wipe the screen with alcohol.
  3. Try adding a print without protection.
  4. If the scanner is working, replace the glass with ultra-thin (no more than 0.15 mm thick) with a cutout under the sensor.

⚠️ Attention: On Xiaomi 12T Pro and 13T Pro fingerprint scanner is combined with heart rate and pulsemeter, and if these functions stop working after the glass is replaced, then the glass is too thick or incorrectly installed.

Diagnostics of the plume and connectors

If the phone fell or was disassembled for repair, the sensor plume could be damaged.

  • The scanner's not responding at all.
  • The phone vibrates when touched, but does not unlock.
  • B Settings → The phone. → All specifications → The condition of the equipment fingerprint sensor marked as defective.

What to do:

  • 🔧 If you disassembled the phone yourself - check whether the sensor plume is tightly connected to the motherboard.
  • 🔍 In the service center, a plume is diagnosed using a multimeter (contact vertebrating).
  • 💰 The cost of replacing the plume: from 800 to 2500 rubles (depending on the model).
What does a damaged sensor plume look like?
The photos below show typical damage to the Xiaomi fingerprint scanner plume: 1. The track break shows black lines or breaks on the flexible board. 2. Contact oxidation is green or white on copper contacts. 3. Mechanical wear - the plume rubbed against the body (often after replacing the battery). If you notice any of these signs, the plume must be replaced.

4. Replacement of the fingerprint sensor

If the sensor is physically damaged (cracks, dents, moisture), it will have to be replaced.

Xiaomi modelType of sensorCost of replacement (₽)Difficulty
Redmi Note 10/11Capacitive (in the button)1200–1800Medium
POCO X3/X4Optical (under the screen)2000–3000Tall.
Xiaomi 12/13 ProUltrasonic.3500–5000Very high.
Mi 11 LiteOptical (in screen)2500–3500Tall.

Important: On models with an ultrasonic scanner (Xiaomi 13 Ultra, Mix Fold 2), replacing the sensor requires calibration in the service center using special software.

💡

If the scanner still doesn't work after you replace the sensor, check if the persist.fingerprint.config settings in the engineering menu are lost. To reset, type in ##4636## and select Hardware Testing. → Fingerprint Test.

Failures MIUI: hidden settings and commands ADB

Sometimes the fingerprint scanner doesn’t work because of firmware bugs or conflicts with settings. MIUI. Let’s look at advanced diagnostic methods.

1. Check the status of the sensor in the engineering menu

To make sure the sensor is physically fit:

  1. Open the dialer and type ##4636##.
  2. Go to Hardware Testing → Fingerprint Test.
  3. If the test shows Failed, the problem is in the hardware.
  4. If the test passes, but the scanner does not work in the system, the software is to blame.

2. reset the sensor settings through ADB

If the standard reset didn’t help, try resetting the sensor settings via Android Debug Bridge (ADB):

adb shell pm clear com.android.biometrics.fingerprint


adb shell pm clear com.miui.biometric

Instructions:

  1. Install ADB Tools on your PC.
  2. Enable USB Debugging in Settings → About Phone → MIUI version (click 7 times, then go back to Additional Settings → For Developers).
  3. Connect your phone to your PC and execute the commands above.
  4. Reset the device.

3. Disabling conflicting applications

Some applications (e.g. Google Smart Lock, LastPass, 1Password) They can block the scanner:

  1. Launch your phone in Safe Mode (hold the power button) → Safe regime).
  2. Try adding a fingerprint in safe mode.
  3. If the scanner is up, remove the recently installed security apps.

4. Manually activating the sensor through the developer settings

On some firmware, the scanner is shut down because of the power optimization, so you can force it to turn on:

  1. Activate Developer Mode (see paragraph 2 of the previous section).
  2. Go to Settings → Additional settings → For developers.
  3. Find the option to turn off permissions for fingerprints and make sure it is turned off.

💡

If after all the manipulations the scanner still does not work, but the test is successful in the engineering menu - the problem is the conflict of modules. MIUI. Solution: Swipe your phone through Fastboot with a full reset (not through a full reset) OTA!).

Some Xiaomi models have unique problems with the fingerprint scanner.

Redmi Note 10/11/12 Pro (optical scanner under the screen)

Typical problems:

  • 🔦 The scanner does not work well in bright sunlight (optical sensor will go blind from IR radiation).
  • 📱 Does not recognize fingerprints after changing the display (recalibrate the sensor).
  • 🔋 It stops working at less than 10% charge (energy saving).

Decisions:

  • To calibrate after changing the screen, type in dial ##86583## and follow the instructions.
  • Turn off Adaptive Brightness in the screen settings – it may interfere with the sensor.

POCO X3/X4/X5 Pro (capacitive scanner in the button)

Typical problems:

  • 🔄 The power button stops working after falling (the plume leaves).
  • 💦 Sensor fails after moisture (corrosion of contacts).
  • 🔋 The scanner is disabled in Ultra Battery Saver mode.

Decisions:

  • If the button is not pressed, take the phone apart and check the plume (see the section on hardware problems).
  • To recover from moisture, use alcohol and an ultrasonic bath (only in the service!).

Xiaomi 12/13/14 Pro (ultrasonic scanner)

Typical problems:

  • 🩹 The sensor stops working after the glass is replaced (original glass with a cutout is required).
  • 🔊 Squeak or vibration appears when touched (damaged piezoele).
  • 📱 Does not recognize fingerprints in gloves (even if the function is enabled).

Decisions:

  • To calibrate the ultrasonic sensor, use the command: adb shell cmd fingerprintd calibrate
  • If the scanner is beeping, it's a sign of a short circuit, turn off your phone immediately and call the service.

How to Prevent Scanner Problems in the Future

To make the fingerprint scanner on Xiaomi last longer, follow these guidelines:

  • 🧴 Clean the sensor of fat and dust regularly (once a week).
  • 📱 Use only certified safety glasses with a cutout under the scanner.
  • 🔋 Avoid battery discharge below 10% – in this mode, the sensor turns off.
  • 🔄 Don't update. MIUI In the first 2 weeks after the release (wait for reviews about bugs).
  • 💧 Avoid getting moisture – even if the phone is waterproof (IP53/IP68), sensor.
  • 🛠️ When self-repairing (replacement of the battery, screen), turn off the sensor plume so as not to damage it.

Tip for flagship owners: On Xiaomi 13 Ultra and Mix Fold 3, the scanner is combined with a heartbeat sensor. If you notice that the pulsemeter is showing incorrect data, this is the first sign of wear and tear of the ultrasound module. Contact the service before the fingerprint scanner stops working completely.

💡

If you use a scanner frequently, add a spare fingerprint (such as the index finger of the other hand) to help if the main finger is damaged or wet.

Frequent Questions About Xiaomi’s Fingerprint Scanner

❓ Why Xiaomi’s fingerprint scanner only works after a reboot?
This is a typical sign of a failure in the biometric service Solutions: Clear the cache of the com.miui.biometric application through Settings → Annexes → App management. Turn off battery optimization for this app. If there's a problem, run your phone through Fastboot with a full reset.
❓ Can I repair the fingerprint scanner myself?
Depends on the problem: ✅ You can: Clean the sensor, reset settings, flashing. ⚠️ Risky: Replacement of the plume (swinging iron and experience required). ❌ You can't: Replace the ultrasonic sensor (you need calibration in the service); If you're not sure about your skills, you better contact the service. The cost of repairs after a failed self-attempt is usually 2-3 times higher.
❓ Why Xiaomi’s fingerprint scanner doesn’t work with gloves?
Most scanners on Xiaomi (except ultrasonic ones) do not support recognition through gloves.Exceptions: Xiaomi 13 Ultra (ultrasonic sensor). K60 Pro (optical scanner with improved software). For other models of the solution: Enable the function of recognition in gloves (if there is in the settings). Add a fingerprint without a glove, then try unlocking in a glove - sometimes works. Use thin gloves (for example, for touch screens).
❓ How to transfer fingerprints to the new Xiaomi?
Unfortunately, fingerprints cannot be transferred - they are tied to the sensor's hardware identifier. When switching to a new phone: On an old phone, export security settings through Settings → Google → Backup (but it won't carry prints!) Add the fingerprints again on the new phone. Exception: if you change the display module (for example, on the Redmi Note 11 Pro).+), The scanner can save the prints, but you will need to recalibrate.
❓ Why Xiaomi’s fingerprint scanner is warming up?
Heating the sensor is a dangerous symptom: 🔥 Short circuit in the plume or controller (urgent repairs required!). 📱 Processor overload (for example, when playing) + charging). 🔋 Faulty battery (swelling may press on sensor plume). What to do: Turn off phone immediately. Check if battery is swelling (carefully press the back cover - if it's bent, don't turn on phone!) Contact diagnostics service. ⚠️ Warning: If the sensor is not only warming, but also beeping or vibrating, it is a sign of a breakdown of the capacitors.