Why Xiaomi’s fingerprint doesn’t work: all the reasons and ways to fix it

You try to unlock Xiaomi with a normal movement, but the fingerprint scanner stubbornly ignores your attempts? The problem is familiar to many owners of Redmi, Poco or Mi smartphones — suddenly stops working the sensor, although yesterday everything worked perfectly. 80% of the failure is not due to hardware failure, but to software failures or improper settings. But how do you know what exactly failed?

In this article, we’ll look at all the possible reasons why a Xiaomi fingerprint scanner might not recognize a finger, from the cluttered contamination of the sensor to hidden firmware errors. You’ll learn how to diagnose a problem in 2 minutes, what settings to check first, and when to really carry the phone to the service. And for models with an ultrasonic scanner (for example, Xiaomi Mi 11 Ultra), we’ve prepared some recommendations – their sensors require a special approach.

And we warn you right away, if you've recently updated your MIUI or dropped your phone, the chances of a software failure triple, but don't panic, 95 percent of the time, you can solve the problem yourself without the help of a master. Let's start with the simplest one.

1. Checking the obvious: dirt, moisture and mechanical damage

The first thing to rule out is the physical obstruction between the finger and the sensor. Xiaomi fingerprint scanners (especially optical and ultrasonic) are extremely sensitive to the slightest contamination, and even a thin layer of fat or dust can block the reading.

Here's what we need to do right now:

• 🧼 Wipe the sensor with a dry microfiber (don’t use alcohol or wet wipes – they can damage the coating!). For models with a subscreen scanner (like the Redmi Note 10 Pro), gently clean the area under the display.
• 💧 Check if there's moisture in the sensor connector. If the phone has recently come into contact with water, let it dry for 12 to 24 hours. Ultrasonic scanners (like the Mi Mix 4) are particularly vulnerable to moisture.
• 🔍 Check the sensor for scratches or chips. Physical damage often causes Poco to fail. X3 Other budget models with mechanical buttons-scanners.
• 👆 Try the other finger. If the scanner recognizes even one fingerprint, the problem lies in the stored template, not in the sensor itself.

⚠️ Warning: Never use abrasive materials (such as paper wipes) to clean the sensor. They leave micro scratches that will eventually lead to complete failure of the scanner. For persistent contaminants, it is better to use a special napkin for optics (suitable for glasses).

2. Software glitches: reboot, cache and updates

If the sensor is clean but the print still doesn't work, the software is to blame: In MIUI, the fingerprint scanner is controlled by a separate module that can "hang" after an update or due to conflict with other applications.

First steps to eliminate:

• 🔄 Reboot your phone. It's trivial, but 30 percent of the time, it solves the problem, especially if it's a failure after a long time without turning it off.
• 📱 Delete and re-add the fingerprint. To do this, go to Settings. → Passwords and security → Fingerprint, delete all the fingerprints you saved, and add them again. When you add more, press your finger, the scanner should capture more details.
• 🗑️ Clear the system cache. Go to Settings. → Annexes → Application management → Three dots (menu) → Show system-based → Biometric service and click "Clear cache».
• 🔧 Update. MIUI In older firmware (especially on Redmi 9 and Poco) M3) There were fingerprint recognition bugs after the screen was locked.

⚠️ Note: If after the update MIUI The scanner stopped working at all, try to roll back to the previous version through Settings → The phone. → Updating the system → Three points. → Select the service pack. This method only works if you have a firmware file (.zip) saved on your device.

3. Conflict with applications and security settings

Xiaomi fingerprint scanner may be blocked due to:

• 🔒 Third-party launchers (such as Nova Launcher or Apex) that interfere with system services.
• 🛡️ Clean Master, 360 Security, which mistakenly blocks biometric data.
• 🔄 Developer Mode if debugging options affecting security are enabled.
• 📱 Dual Apps (Dual Apps function) MIUI), which may conflict with the system services.

How to check:

1. Run your phone in Safe Mode (press the power button → long tap on "Switch off" → "Safe Mode"). If the scanner is running, one of the installed applications is to blame.
2. Turn off all optimizers and antiviruses, then restart the device.
3. Check the developer mode settings: go to Settings → About Phone → MIUI version (shoot 7 times), then to Settings → Additional → For Developers and turn off the USB Debugging and OTG Verification options.

⚠️ Note: If you are using a custom recavator (TWRP) or root right (Magisk), the fingerprint scanner may not work due to a breach of system partition integrity /vendor. In this case, only the refrigeration of stock will help. MIUI via Fastboot.

4. Hardware problems: when you need to service

If none of the software methods worked, the problem is likely hardware, and here are the signs that the sensor is physically malfunctioning:

• 🔴 The scanner does not respond at all (no vibration, backlight or audible signal when touched).
• 💥 The phone fell or was hit in the sensor area (even if there is no external damage).
• 🔌 After the screen or battery was replaced, the scanner stopped working (especially for the Redmi Note 8 Pro and Poco). F1).
• 🔥 The phone overheated (for example, after charging with a non-original adapter).

What you can do on your own:

• 🔧 Check the sensor plume (if you've taken your phone apart) on mechanical button-scanner models (like Redmi 7), the plume often leaves after falls.
• 🔋 Check the battery. A bloated battery can push the motherboard and disrupt the sensor.
• 📡 Reset network settings (sometimes scanner problems are caused by module damage) NFC, near-sensor).

When to contact the service:

⚠️ Note: If you decide to replace the sensor yourself, consider that on Xiaomi models with a subscreen scanner (for example, Mi). 10T or Redmi K40) Without special software (for example, Mi Flash Pro), the scanner will not work even with a new sensor.

Features of subscreen scanners (optical and ultrasonic)

Xiaomi smartphones with subscreen scanners (e.g. Mi 11, Redmi K50, Poco F4) require a special approach. Their sensors are integrated into the display and depend on the screen performance. Here's what can go wrong:

• 📱 Film or glass interferes with scanning. Optical scanners (like in the Redmi Note 11 Pro)+) Do not work through thick protective glass or metallized films.
• 🔦 Ultrasonic scanners (such as those in the Mi Mix 4) require a minimum brightness of 30-40% to work properly.
• 🔄 The firmware update reset the display settings. MIUI Recalibration of the scanner may be required.
• 💡 The backlight of the screen is uneven (for example, due to broken pixels in the sensor area). OLED-screen.

Solutions for subscreen scanners:

1. Take off the protective glass or film and check the scanner without them, if it works, you will have to find a compatible glass (for example, with a cutout for the sensor).
2. Increase the brightness of the screen to 50% and turn off the adaptive lighting in Settings → Display.
3. Calibrate the scanner through the engineering menu: ##6484## → “Fingerprint Test” → “Calibration” Does not work on all models!
4. If the scanner flashes green but doesn’t recognize the fingerprint, try adding a finger in different lights (e.g., in a dark room and in bright light).

Ultrasonic scanners (as in the Mi Mix 4) can be temporarily shut down at temperatures below +5°C or above +40°C. This is normal behavior – the sensor is automatically locked to protect against damage.

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If you have Xiaomi with AMOLED-With a screen and a scanner, never set dark wallpaper themes in the sensor area. The optical scanner uses the backlight to work, and dark pixels can interfere with reading.

6. Resetting settings and extreme measures

If all the previous methods didn't work, you're left with a reset, which is a radical solution, but it works in 90 percent of cases where the problem is caused by a software failure.

How to reset your settings without losing data:

1. Back up via Settings → About Phone → Backup or Mi Cloud.
2. Go to Settings → About Phone → Reset and select Reset All Settings (not to be confused with Reset to Factory!) This will save your files but remove the application and system settings.
3. After reset, do not restore the settings from the backup - add the fingerprint again.

If this does not work, you will have to do a full reset:

1. Turn off the phone.
2. Press the Power button + Volume up until the Mi logo appears.
3. From the recovery menu, select Wipe Data → Wipe All Data.
4. After resetting, set the phone as new and check the scanner.

⚠️ Note: On some models (Poco) F3, Redmi K30 Pro) after hard reset, you need to re-activate the device via Mi Account. Make sure to remember the username and password from the Xiaomi account, otherwise the phone may be blocked!

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If the scanner doesn't work even after a complete reset, the problem is definitely hardware, in which case don't waste time on software methods - take the phone to the service center.

7. Alternative ways to unlock if the scanner is not working

While you're looking for a solution, the phone needs to be unlocked somehow. Here are all the available fingerprint alternatives on Xiaomi:

• 🔐 PIN-It's the most secure option, but it requires you to enter it every time.
• 👤 Facial recognition works even in the dark on models with an IR camera (e.g. Mi 11 Lite).
• 📍 Smart Lock. Set up automatic unlock in secure locations (home, work) via Settings → Passwords and security → Smart Lock.
• 🔑 Temporary pattern lock. You can set as a backup in Settings → Passwords and security → Screen locking.
• 📱 Smart watch or bracelet. If you have a Mi Band or Amazfit, set it to unlock in Settings. → Connected devices.

⚠️ Note: If you only used your fingerprint to unlock and forgot PIN-You have to do a hard reset that will delete all the files from your phone. To avoid this in the future, always set up a backup method to unlock (PIN password).

FAQ: Frequent questions about the fingerprint scanner on Xiaomi