Why a fingerprint doesn’t work well on Xiaomi Redmi: a full analysis of the causes and solutions

The Xiaomi Redmi fingerprint scanner should make life easier: quick unlocking, payment confirmation, access to secure folders. But what if the sensor suddenly stops working? It doesn't recognize your finger, it reacts once, it ignores touches altogether. The problem is familiar to owners of Redmi Note 10/11/12, POCO X3/X4 and other models with a physical or underscreen scanner.

In this article, we have 7 proven causes of malfunction (from commonplace contamination to hardware defects) and step-by-step solutions for each. We won’t recommend “rebooting your phone” — instead, we’ll look at the unique nuances of MIUI firmware, the features of Goodix and FPC sensors, and the hidden settings that even service centers don’t talk about. If you’ve tried resetting or updating your software, you’ll find alternative methods here.

1. Pollution of the sensor or protective glass

The most obvious but often ignored reason: The fingerprint scanner on Redmi may not work well because of:

• 🧴 Fat and sweat – the remains from the fingers form a film that interferes with reading.
• 💎 Scratching on glass – even microscopic damage distorts the signal.
• 🧴 Creams or antiseptics - alcohol compositions leave a sticky plaque.
• 🛡️ Films or covers – poor quality accessories block access to the sensor.

How to Clean the Scanner Correctly:

1. Turn off the phone.
2. Wet the cotton swab in isopropyl alcohol (70%+) or a special liquid to clean the screens.
3. Gently wipe the sensor area without pressing (especially if it’s a subscreen scanner on the Redmi Note 11 Pro+).
4. Let dry 2-3 minutes before turning on.

💡

If you use a gel film, make sure it doesn't cover the scanner area with the edges, and on models with a subscreen sensor (like the Redmi K50), there's enough displacement of 0.5 mm to make reading impossible.

⚠️ Warning: Do not use acetone, solvents or abrasive materials - they will damage the oleophobic coating and the sensor itself. If after cleaning the problem remains, proceed to the next point.

Damage to the sensor or plume

Physical defects are the second most common cause of a scanner that is not working.

• 🔴 The sensor does not react at all (no vibration, backlights).
• 🔄 It only works after multiple clicks.
• 💥 Appeared after a fall, impact or repair (such as a screen change).

How to check:

1. Run the Equipment Test using ##6484## (on some models #4636###).
2. Select Fingerprint Test – if the test doesn’t start or if it comes up with an error, the problem is hardware.
3. Check if the sensor plume is moving away (relevant after disassembling the phone).

⚠️ Warning: If your phone falls or gets wet, don’t try to disassemble it yourself – on models with a subscreen scanner (Redmi Note 11 Pro)+, K50) The sensor is glued to the display, and if you take it down, it'll cause the screen to be completely inoperable.

3. Problems with firmware or MIUI

The fingerprint scanner on Xiaomi is closely related to system software. Errors can occur after:

• 🔄 Updates MIUI (especially on the beta versions).
• ⚙️ Resetting settings without removing old prints.
• 📱 Install custom firmware (for example, Pixel Experience).
• 🔒 Activation of the developer mode with changing security settings.

How to fix software failures:

1. Remove all saved fingerprints to Settings → Passwords & Security → Fingerprint and add again.
2. Reset security settings through Settings → About Phone → Resetting Settings → Resetting security settings.
3. If the problem appears after the update, roll back to the old version of MIUI via Settings → System Update → Three Points → Select the Service Pack.

⚠️ Note: On some models (Redmi Note 10 Pro, POCO F3) When you reset your settings, the scanner stops working until you're completely flashing it through Fastboot.

4. Conflict with applications or launchers

Few people know, but third-party launchers (for example, Nova Launcher, Apex) or locking applications (AppLock, FingerSecurity) can block access to the sensor.

• 🔒 Use of VPN or antiviruses with fingerprint scanning function.
• 🎮 Activate Game Turbo mode, which disables background processes.
• 📱 Installation of Magisk modules (e.g. BiometricPrompt) API).

How to diagnose and eliminate:

1. Run your phone in Safe Mode (press the power button → Safe Mode) If the scanner is running, it's third-party software.
2. Check permissions for applications in Settings → Applications → Permissions Management → Biometric data.
3. Turn off battery optimization for system services: Settings → Battery → Battery Optimization → Three points → Show everything → Find “BiometricService” and turn off optimization.

Wear or damage to the power button (on side-scanner models)

On the Redmi Note 10, 9T, POCO M3 and other side-scanner models (built into the power button), the problem is often mechanical wear.

• 🔘 The button fails or the clinite.
• 🔋 The scanner only works when pressed hard.
• 🔌 The phone spontaneously turns off when unlocked.

Decisions:

1. Try tapping the button carefully (sometimes helps with contact oxidation).
2. If the button is "disclaimed", it can be glued with double-sided tape (temporary solution).
3. For complete repairs, a button with a sensor is required (cost: 800-1 500) ₽).

⚠️ Note: On Redmi Note models 10S and POCO X3 NFC The power button is connected to the scanner with a single plume, and if you take it apart, you're likely to damage the sensor, so you'd better have the repair done by a specialist.

6. Incorrect security settings or Mi Account settings

The fingerprint scanner on Xiaomi is linked to the Mi Account and lock settings.

• 🔑 You changed your password/pattern lock but didn’t update your fingerprints.
• 📱 The phone is linked to another Mi Account (for example, after buying a used one).
• 🔒 The “Find Device” function with remote lock is activated.

What to do:

1. Make sure to Settings → Accounts → Mi Account is tied to your account.
2. If the phone is used, perform a full reset via Settings → About Phone → Resetting (remove all data!).
3. Check if the remote lock is activated on i.mi.com.

💡

On models with MIUI 14+, the fingerprint scanner will not work unless a PIN or password is installed on the system. Add it to Settings → Passwords and Security → Screen Lock.

7. Hardware features of specific models

Some Redmi models have unique scanner issues:

⚠️ Attention: Redmi Note 12 Pro+ with an ultrasound scanner (Qualcomm) 3D Sonic may be incompatible with some of the security windows, so if the scanner stopped working after sticking the glass, try removing it or using a model with a cutout under the sensor.

FAQ: Frequent questions about the fingerprint scanner on Redmi