Xiaomi’s Fingerprint Checker: A Complete Guide from Setup to Fault Diagnostics

The fingerprint scanner in Xiaomi smartphones is not only a convenient way to unlock, but also an important security element. However, many users face problems: the device does not recognize the finger, runs with delays or refuses to scan at all, most often due to incorrect settings, a contaminated sensor or software failures. In this article, we will discuss all the ways to check the fingerprint, from basic settings to the diagnosis of hardware malfunctions.

You will learn how to add a fingerprint correctly, test it in different scenarios (unlock, pay, access to applications), as well as what to do if the scanner stopped functioning after the update. MIUI Special attention will be paid to models with a subscreen sensor (Xiaomi 13 Pro, Redmi Note 12 Pro).+), where the scanning algorithms differ from the classical sensors.

If your Xiaomi ignores the fingerprints or gives an error "failed to recognize", do not rush to bring it to the service center. In 80% of cases, the problem can be solved yourself - just follow our recommendations and use hidden MIUI features that are not written in the official instructions.

1. Preparing the smartphone before checking the fingerprint

Before testing the scanner, make sure your Xiaomi is ready for the procedure. Many users miss this stage, which leads to false positives or recognition errors.

First, clean the fingerprint sensor. Physical sensors (such as the Redmi Note 10) often accumulate fat, dust or moisture that interfere with scanning. Use soft lilac-free fabric moistened in an alcohol solution (at least 70%). For underscreen sensors (Xiaomi 12T, POCO F5) dry wipes are sufficient - aggressive liquids can damage the oleophobic coating of the screen.

Second, check your finger, if you're wet, sweaty or damaged (with cuts, calluses), your fingers are less recognizable, and you also avoid high pressure, because the sensor should be able to touch the skin, rather than pressing in.

• 🔹 Ambient temperature: sub-zero temperatures make your skin dry, which makes scans worse.
• 🔹 Protective films: thick or poor quality films on the screen can block the subscreen sensor.
• 🔹 System updates: if the scanner stopped working after the update MIUI, Check for patches in Settings → The phone. → Updating the system.

Critical error: If the scanner does not respond after cleaning the sensor and finger, this may indicate damage to the plume (relevant for models with a physical sensor on the back, for example, Redmi 9A), in which case diagnostics will be required in the service center.

2.How to add a fingerprint to Xiaomi: step-by-step instructions

The process of adding a fingerprint is the same for most Xiaomi models, but there are nuances depending on the version of the MIUI and the type of sensor.

1. Go to Settings → Passwords and Security → Fingerprint.

2. Enter. PIN-code or pattern lock (if not installed, the system will prompt you to create it).

3.Push Add Fingerprint and touch the sensor slightly.

4. Follow the on-screen prompts: the system will ask you to raise and lower your finger, and use different parts of the pad for a full scan.

Important: during the scanning phase, do not change the angle of the finger, this will lead to recognition errors in the future. If the system sends a message "Too fast" or "Insufficient data", repeat the procedure by holding your finger on the sensor for longer than 1-2 seconds.

Install PIN-code|Clean the sensor and finger|Make sure there is no skin damage|Use the same finger at all stages of the scan-->

On models with a subscreen sensor (Xiaomi 13, Mix 4), the scanning algorithm is different: the system asks for a stronger finger and hold it until vibration.

⚠️ Warning: If the scanner is unstable after adding a fingerprint, delete it and repeat the procedure. MIUI There is a limitation: up to 5 prints can be saved, but it is recommended to use no more than 3 for a single user.

3. Testing of fingerprint: how to check the performance

Add a print, half the way, make sure it works in different scenarios.

• 🔓 Unlock the screen: Lock the smartphone and try to unlock it with a fingerprint. 5-10 once in a row - if at least once the scanner did not work, the problem is the quality of the scan.
• 💳 Payment through NFC: Add the card to Mi Pay or Google Pay and try to pay with a fingerprint. Some banks require a re-scan, which is normal.
• 🔐 Access to applications: in security settings (Settings) → Passwords and security → Privacy: Enable fingerprint unlocking for gallery, notes or banking applications.

If the print doesn’t work in one scenario, but the screen unlock is successful, the problem lies in the settings of a particular application. For example, Google Pay can block payment with a fingerprint if the smartphone has enabled the Android Remote Management feature (you can find it in Settings → Google → Security).

For deep diagnosis, use the hidden sensor test:

1. Enter the phone app code ##4636##.
2. Select Hardware Test (some models may call it Hardware Test).
3. Find the Fingerprint Sensor section and follow the instructions on the screen.

If the test ends with an error, it may indicate a hardware failure, in which case, try resetting the security settings (Settings → Passwords and Security → Reset fingerprint settings).

Physical (back) | Subscreen (optical) | Side (power button) | Don't know-->

4. Common mistakes and their solutions

Even after you set up the fingerprint scanner correctly, it can malfunction, and let's look at the typical problems and how to fix them:

The problem with subscreen sensors on Xiaomi 12/13 series models deserves special attention. If the scanner works only in bright light, this may be due to a malfunction of the sensor backlight, in which case only replacing the module in the service center will help.

Another common situation is that the fingerprint stops working after resetting, which is because MIUI encrypts the fingerprint data with a link to the Mi Account, and when you reset, the link is lost, and the scanner needs to be reconfigured.

⚠️ Note: If you use magnet covers (for example, for wireless charging), they may interfere with the operation of side fingerprint sensors (as on the other hand). POCO X5 Try removing the case before the scan.

5. Checking the fingerprint on different Xiaomi models: features

The algorithms of the fingerprint scanner vary depending on the model and type of sensor.

Models with a physical sensor (2018-2021):

• 📱 Redmi Note 8/9/10, Mi A3: The sensor is on the back, sensitive to contamination and mechanical damage, and the plume can move when the smartphone falls.
• 📱 POCO X3, Redmi K30: side sensor in the power button, often broken by moisture.

Models with subscreen sensor (2020-2026):

• 📱 Xiaomi Mi 11, 12 Pro: optical sensor, requires bright screen illumination to work.
• 📱 Redmi Note 12 Pro+, POCO F5: ultrasonic sensor (less commonly), more reliable, but sensitive to moisture on the screen.

The new flagships (Xiaomi 14, Mix Fold 3) are used 3D-A fingerprint scanner that recognizes not only the pattern of the skin, but also the depth of the papillary lines, which improves safety, but requires more precise finger positioning.

If you are not sure what type of sensor is installed in your model, check the specifications on the official Xiaomi website or use the AIDA64 app (Sensors section).

6. Diagnostics of hardware malfunctions

If all software methods have been tried, but the fingerprint scanner still doesn't work, it could be a hardware breakdown.

Signs of sensor malfunction:

• 🚨 The scanner does not respond to touch at all (no vibration, backlights).
• 🚨 In the menu of the addition of the fingerprint, an error appears "No sensor detected".
• 🚨 After falling or getting moisture, the print stopped working.

To check the hardware:

1. Connect your smartphone to your PC and launch ADB (instruction below). Enter the command: adb shell dumpsys fingerprint If the answer has mSensor=null, the sensor is not determined by the system.
2. Check the integrity of the plume (relevant for models with a physical sensor). To do this, disassemble the phone or contact the service.

On models with a subscreen sensor (Xiaomi 13 Ultra, Mix 4), a common problem is the detachment of the sensor from the screen. This occurs due to overheating or mechanical pressure. Signs: the scanner only works when you press a certain area of the screen hard.

⚠️ Warning: If you suspect a hardware malfunction, don’t try to disassemble the phone yourself – this can damage the flexible plumes. In Xiaomi models, the fingerprint sensor is often integrated into the display module, and its replacement requires a complete disassembly of the screen.

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

If the fingerprint scanner fails, don't go unprotected. MIUI has several alternative unlocking methods:

• 🔐 PIN-Code or password: the most reliable option. Set a code not shorter than 6 characters.
• 🖼️ pattern lock: convenient, but less secure – you can see the traces on the screen.
• 👤 Facial recognition: works on most Xiaomi models (except budget ones). → Passwords and security → Facial recognition.
• 📍 Smart Lock: Automatically unlock in trusted locations (home, work) or when connected to a trusted device (e.g. Mi Band).

For maximum safety, we recommend using a combination of methods. + PIN-face-code + It's a pattern lock, and it'll protect your data, even if one of the ways it works stops working.

If you lose access to all unlock methods, use the Find the device in your Mi Account function, which allows you to remotely reset your password (provided that the phone is connected to the Internet).

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On models with MIUI 14 and later, you can configure emergency unlock via SMS. To do this, go to Settings → Passwords and security → Emergency information and specify a trusted number.

8 Frequently Asked Questions

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If the fingerprint scanner stopped working after falling or getting moisture, the sensor or its plume is likely damaged, in which case professional repair is required.