The Xiaomi Redmi 9A fingerprint scanner is not just a convenient way to unlock, but a full-fledged personal data protection tool. Despite the budget position of the model, the biometric authentication function here is implemented at the flagship level - if you set it up correctly. However, many users face problems: the system does not find the sensor, the fingerprint is not saved or the smartphone refuses to recognize the finger after an update.
In this article, we will look at all the steps of the setup, from hardware compatibility checks to sensor calibration, and learn why the Redmi 9A can’t see the scanner (yes, it does!), how to add up to 5 fingerprints, and what to do if the system produces a “failed to register a fingerprint” error, and a secret life hack, how to speed up recognition by 30% due to the correct position of the finger.
Important: the manual is relevant for all versions of MIUI 12, 13 and 14, including global and Chinese firmware. If your smartphone is custom built (for example, LineageOS or Pixel Experience), some points may differ - we will mention this too.
Compatibility Check: Is there a scanner on your Redmi 9A?
Before you try to adjust the print, make sure that your Redmi 9A model is equipped with a sensor at all. The fact is that not all versions of this smartphone have a scanner - it depends on the region and year of release.
How to check:
- 🔍 Inspect the back panel: the sensor is located under the camera, has the shape of a circle or oval depression with a metal rim.
- 📱 Go to Settings. → The phone. → The full specifications should have a fingerprint scanner in the Sensors section.
- 🛠️ Type "fingerprint" into your settings search. If the system doesn't find the corresponding partition, there's no sensor.
If the scanner is not physically available but you want biometric unlocking, consider alternatives:
- 👁️ Facial recognition (works even in the dark) MIUI 14).
- 🔑 pattern lock or PIN-code with Smart Lock function (automatic unlock in trusted places).
⚠️ Attention: Some Redmis 9A for the Indian market (model) M2006C3LG) There's no fingerprint scanner, but the specification may be wrong!
Preparation of the smartphone: what to do before setting up
To avoid errors when registering a fingerprint, follow the preliminary steps:
Update MIUI to the latest version
Remove the protective film/case from the sensor area
Clean your finger and scanner with an alcohol napkin
Make sure that the battery is >20%
Turn off the power saving mode-->
Pay special attention to the cleanliness of the sensor. Dust, grease or scratches on the scanner glass can cause malfunctions.
- 🧴 Microfibre wipe (as for glasses).
- 💧 Isopropyl alcohol (70% or higher) – apply on a napkin, not on a sensor!
- ❌ Prohibited: abrasives, wet wipes with flavors, needles for cleaning.
If you've recently updated your firmware, restart your smartphone before setting up, which will reset the sensor cache and prevent the "Scanner is not responding" error.
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If the fingerprint sensor heats up during registration, that's fine. But if it stays hot after the process is complete, check your smartphone for viruses or reset the scanner settings in Settings → Applications → App Management → Fingerprint Scanner → Storage → Clear the data
Step-by-step: how to add a fingerprint
Now, to the point, follow the instructions carefully, and the way you do it depends on the quality of the recognition.
- Open Settings → Passwords and Security → Fingerprints.
- Enter the current one. PIN-code, password or pattern lock (if not installed, the system will require you to create it).
- Click "Add fingerprint" and select a finger (e.g., "Right hand index").
- Put your finger on the sensor and wait for the vibrations to occur. Don't tear your finger off until the system asks you to change position (usually 3-5 touches are required).
- Raise your finger when the tick lights up. Repeat the process for the other corners of your finger (edge, center, sides).
- Click "Ready" when you have reached 100% progress.
Critical: When registering, raise your finger between touches for 1-2 seconds, which allows the sensor to “reset” the data of the previous scan and avoid duplicate fingerprint error.
| Problem. | Reason. | Decision |
|---|---|---|
| The scanner doesn't respond to touch. | Contaminated sensor or finger | Clean with alcohol, dry for 5 minutes |
| The system asks you to change the position of your finger too often. | Touching too fast | Hold your finger 2-3 seconds between position changes |
| The fingerprint is retained but not recognized | Insufficient data (low percentage coverage) | Remove and add the fingerprint again, capture the edges of the finger |
| Error "The fingerprint scanner is not working" | Software failure or sensor damage | Restart your phone or reset your scanner settings |
Optimizing Recognition: Secrets of Precision Work
Even a properly added print can be unstable. Here's how to improve accuracy:
- 👆 Add the same finger 2 times at different angles (for example, "Right hand pointer" and "Right hand pointer - side pointer").
- 💦 If your fingers are wet or sweaty, wipe them with a dry wipe before unlocking.
- 🔄 After 3 failed attempts, the system will block the scanner for 30 seconds – this is normal behavior. MIUI.
To speed up recognition:
- Activate the option “Unlock when touching the screen” in the fingerprint settings.
- Turn off the unlock animation in Settings → Design → System animation.
- Add a fingerprint of your dominant hand (the one you hold your phone with more often).
How does the scanner work on Redmi 9A?
Error Fixing: What to Do When Your Fingerprint Is Not Working
If the scanner refuses to recognize the fingerprint or gives out errors, try these methods:
⚠️ Warning: If after the phone crashes, the scanner stopped working, don't try to disassemble the device yourself. 9A It's connected to the motherboard in a thin plume, easy to damage).
- 🔄 Reset scanner settings: Go to Settings → Annexes → Application management. Find "Fingerprint Scanner" (or "Biometric Service"). Press "Storage" → "Clear the data. Restart the phone and add the print again.
Firmware integrity check:
Enter the phone app code ##4636## → select Phone Information → scroll to the fingerprint box. If the status is not supported, flash it.If the problem occurred after the MIUI update, try to roll back to the previous version via Settings → About Phone → System Update → Three Points → Select an update pack. Download the old firmware from the official Xiaomi website (section Redmi 9A).
Security: How to protect data when using a fingerprint
Biometric unlocking is convenient, but it has vulnerabilities. Here's how to minimize the risks:
- 🔒 Always set up a backup. PIN-The code is more complex than 1234 or date of birth. PIN — Not (if it's reliable).
- 🚫 Turn off the “Smart Lock” option if you store financial data on your phone.
- 📵 Set up automatic fingerprint removal after 5 failed attempts in Settings → Passwords and security → Security settings.
On MIUI 14, a fingerprint can be used not only to unlock, but also to:
- Authorization to Mi Account and Xiaomi Cloud.
- Confirmation of payments in Mi Pay (if a bank card is tied).
- Hiding and displaying folders in the Gallery (the function "Secure storage").
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The Redmi 9A’s fingerprint is stored in a secure enclave of the processor and is not transmitted to the cloud or third-party applications, but when the phone is reset to factory settings, all biometric data is deleted without recovery.