Why the Redmi 8 fingerprint scanner may not work the first time
The fingerprint scanner on Xiaomi Redmi 8 is a convenient feature for quick unlocking, but it is not always smoothly set up. Even if you have previously used biometrics on other smartphones, there are nuances here: The sensor is located on the back, not under the screen, and requires a special angle of the finger, MIUI It can block the addition of fingerprints if basic security conditions are not met, such as the installation of a fingerprint. PIN-code.
In this article, we’ll look at not only the standard fingerprint addition process, but also the hidden MIUI 12/13/14 settings that affect sensor performance, as well as typical user errors. If your Redmi 8 ignores touch or gives you a message that says, “Not Added a fingerprint,” here’s a solution.
Preparation of the smartphone: what to check before setting up
Before you add a print, make sure your Xiaomi Redmi 8 is ready for it.
- 🔒 Whether identified PIN/Without it, the system will not allow the activation of biometrics. If you use a pattern lock, its complexity must be at least average (4+ point).
- 📱 Is the firmware updated? Old versions. MIUI (below 12.0.3) there were bugs with the scanner. → The phone. → Updating the system.
- 🧹 Is the sensor clean? Fat marks or scratches on the sensor (under the camera) interfere with reading.
- 🔋 Battery charge above 20%? Low charge MIUI It can block energy-intensive operations, including biometrics setup.
Pay special attention to the protective film or cover, and if they close the sensor or create an air gap, the scanner will not work smoothly. Try removing the cover while you set it up.
Step-by-step: how to add a fingerprint
Now, let's get to the process. Follow the instructions carefully, the order is important.
- Open security settings: Go to Settings → Passwords & Security → Fingerprint. If not, update MIUI or check the firmware region (for some countries, the feature is disabled).
- Enter your current PIN/password: The system will require you to verify your identity. This is a mandatory step - without it, you can not add a fingerprint.
- Click Add Fingerprint: Select a finger (like your right index hand) and follow the prompts on the screen. The sensor on Redmi 8 requires multiple tapping — at least 10 to 15 times at different angles.
- Adjust your grip: Don't press your finger too hard, the sensor will activate a light touch. If you get a message that says "Too fast," slow down and hold your finger on the sensor for 1-2 seconds.
- Complete the setting: After successful addition, the system will prompt you to name the fingerprint (for example, "Indicator right"). This will help you manage several fingerprints later.
Installed PIN-code|Sensor's clean and not closed.|The smartphone is charged more than 20 times%|Updated firmware MIUI|Removed case (if any)-->
If the error “I failed to recognize the fingerprint” appears during the scanning stage, try:
- 🧼 Wipe your finger and sensor with an alcohol napkin (without isopropyl alcohol!).
- 🔄 Reboot your smartphone and repeat the process.
- 👆 Try the other finger – sometimes the sensor better reads prints from less “erased” pads.
Common Mistakes and How to Fix Them
Even after a successful setup, the scanner may not work as well, and consider the most common problems and their solutions:
| Problem. | Possible cause | Decision |
|---|---|---|
| Sensor doesn't respond to touch | Sensor contamination or software failure | Wipe the sensor, reboot the phone, reset the security settings (Settings → Passwords and Security → Reset settings) |
| The fingerprint is recognized once. | Too fast application or "blurred" print | Remove the current fingerprint and add again, holding the finger 1-2 seconds longer |
| The message is “too many attempts.” | Blocking after 5 failed unlocks | Wait 30 seconds or unlock your phone PIN-code, then repeat |
| The fingerprint function is not in the menu | Outdated firmware or regional restrictions | Update MIUI to the latest version or reflash to the global version |
If none of these things worked, check the physical condition of the sensor. On the Redmi 8, it often suffers from falls - even minor cracks in the back can damage the sensor, in which case you will need to replace the module at the service center.
What if the print is added but does not work to unlock?
Additional settings: speeding up unlock and security
After adding a fingerprint, you can optimize its work:
- ⚡ Accelerated unlock: Turn on the "Unlock When Touch" option in the fingerprint settings. Now you don't have to press the power button - just touch the sensor.
- 🔐 Applications with access: C Settings → Passwords and security → Confidentiality → Special access can be allowed to unlock the fingerprint for individual applications (for example, banking).
- 📱 Standby PIN: Always keep an alternative way of unlocking ready. If the sensor fails, you won't be left without access to the phone.
Pay attention to security: if someone accesses your fingerprint (for example, from a high-resolution photo), they will be able to unlock the phone. MIUI There is protection against this – the system requires confirmation PIN-code after rebooting or after 48 hours without using biometrics.
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If you wear gloves or exercise frequently, add a few fingerprints (such as your index and middle fingers) to increase your chances of unlocking successfully in any situation.
Redmi 8 scanner compared to other Xiaomi models
The fingerprint sensor on the Redmi 8 is from the first generation of Xiaomi rear scanners, and compared to new models (for example, the Redmi Note 11 or the POCO X4 Pro), it has a number of features:
| Characteristics | Redmi 8 | Redmi Note 10/11 | POCO F4 |
|---|---|---|---|
| Type of sensor | Capacitive (back) | Capacitive (side) | Optical (under the screen) |
| Recognition speed | ~0.8 sec. | ~0.5 sec. | ~0.3 sec. |
| Moisture resistance | Low. | Medium | Tall. |
| Max. Number of prints. | 5 | 5 | 5 |
As you can see from the table, the Redmi 8 scanner is inferior to modern models in speed and reliability, but its advantage is the ease of repair. The rear sensor is easier to replace yourself, while subscreen sensors require professional equipment.
What to do if the print stops working after the MIUI update
Firmware updates sometimes reset the biometrics settings or make changes to the recognition algorithms, if the scanner stopped working after the update:
- Delete all saved fingerprints: Go to Settings → Passwords & Security → Fingerprint and delete all records. Then add them again.
- Reset security settings: In the same menu, select Reset settings. This won't delete the data, but will return the biometrics to factory settings.
- Check conflicts with Magisk or custom firmware: If you use root rights or unofficial software, the scanner may be blocked due to changes in /system.
If the problem persists, a rollback to the previous version of MIUI may help.
- Download stable firmware from the official Xiaomi website.
- Go to Settings → About Phone → System Update → Three Dots → Select a firmware file.
- Select the downloaded file and wait for the process to be completed.
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After updating MIUI, always check the biometrics in safe mode (press the power button → Safe Mode). If the scanner is working, the problem is with third-party software.