The fingerprint sensor on Xiaomi Redmi 9 is a convenient feature for quick unlocking, but sometimes users are faced with the need to turn it off. The reasons can range from trivial sensor problems (does not recognize the fingerprint, works with delays) to security problems (for example, if several people use the phone), in some cases, the scanner starts to fire spontaneously, unlocking the device in your pocket or bag, which creates risks of unauthorized access.
In this article, we will discuss all possible ways to deactivate the fingerprint sensor on Redmi 9 – from standard settings to forced reset via Fastboot. MIUI, These are often overlooked in general instructions, such as why after fingerprints are deleted, the scanner can remain active in the background or how to properly disable it without losing data. POCO M3), Most methods will also work, but there may be different paths in the menu.
1. disable the scanner through standard MIUI settings
The easiest and safest way to do this is to deactivate the fingerprint sensor through the settings menu, a method that does not require a super-user (root) right and is suitable for most versions of MIUI 12/13/14 on Redmi 9. Importantly, after disabling all the saved prints will be deleted, but other unlock methods (PIN, pattern lock) will remain valid.
Step instructions:
- 📱 Open the Settings app** (the gear icon on the home screen).
- 🔒 Go to the Passwords and Security section (in some versions) MIUI This can be called locking and protection).
- 👆 Select the Fingerprint (or the Fingerprint Sensor).
- 🗑️ Click Remove fingerprints and confirm the action with input PIN-code/pattern lock.
- ⚙️ In the upper right corner, tap the three-point menu and select Turn off the fingerprint sensor (if option is available).
If you don't have the option to turn off the sensor, your version of MIUI deactivates the scanner automatically after all the fingerprints are deleted, and to check this, try adding a new fingerprint -- if the system suggests turning on the sensor again, it's successfully disabled.
☑️ Checking the scanner's shutdown
2. Forced shutdown through “Developer Mode”
In some cases, standard fingerprint removal does not completely deactivate the sensor, for example, if the scanner continues to consume battery power or is triggered when touching (even without the saved fingerprints), the solution is to disable it through Developer Mode**, where advanced hardware settings are available.
How to activate the developer mode and deactivate the scanner:
- Go to Settings. → The phone.
- Click 7 times in a row on the MIUI version until the notification appears You became a developer!
- Return to the main settings menu and open a new section → For developers.
- Scroll down and find the item Disable fingerprint sensor (or Hardware fingerprint disable in English firmware).
- Activate the switch and restart the device.
What if the item is not in the developer menu?
⚠️ Note: After the scanner is turned off through the developer mode, re-energizing it may require resetting to factory settings. This method is recommended only if the standard methods do not work.
3. Reset security settings (without data loss)
If the fingerprint scanner is active (for example, after a failed MIUI update) and does not respond to commands, a partial reset of security settings will help, which removes all biometric data (fingerprints, facial recognition), but saves applications, photos and other user files.
Step-by-step:
- 🔄 Go to Settings. → Passwords and security.
- 🔐 Select Reset Security Settings (may be called Lock Reset).
- 📱 Enter the current one. PIN-code or pattern lock for confirmation.
- ✅ Confirm reset – all fingerprints and facial recognition data will be deleted.
After restarting, check the scanner: If it is still active, move to more radical methods (see next section). Note that this method will not help if the problem is due to a physical malfunction of the sensor (for example, after a phone drop).
4. Full reset to factory settings (Hard Reset)
The last measure, if the fingerprint scanner doesn't turn off by any other means, is a complete phone reset.This method removes all data from the device, including apps, photos and settings, so pre-back up through Settings → System → Backup or Mi Cloud.
How to perform Hard Reset:
- Open Settings → About the phone → Reset settings.
- Select to erase all data (reset).
- Enter. PIN-code and confirm the action.
- Wait for the process to be completed (it will take 5-10 minutes).
After the reset, the phone will turn on in a "out of the box" state. Don't add fingerprints right away - first check if the scanner is spontaneously activated. If the problem persists, this may indicate a hardware defect (for example, damage to the sensor plume).
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Before resetting, remove the memory card (microSD) and SIM-map to avoid accidental formatting.
5. Disabling the scanner via Fastboot (for advanced users)
If the software methods did not help, and the scanner interferes with the phone (for example, constantly unlocks the device in your pocket), you can turn it off at the firmware level through Fastboot mode. ADB-computer tools and basic knowledge of working with the command line.
Step-by-step:
- Download and install Google’s Platform Tools (includes fastboot and adb).
- Connect Redmi 9 to your PC via USB-Cable and convert it to Fastboot: adb reboot bootloader
- In the command line (on PC) execute the command to disable the sensor: fastboot oem disable-fingerprint If the command is not supported, try: fastboot oem fp-disable
- Reboot the phone: fastboot reboot
⚠️ Note: Not all versions of Redmi 9 support these commands. Some devices may need to run through the Mi Flash Tool to restore performance. Use the method only if you are confident in your actions!
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Disabling the scanner via Fastboot does not guarantee 100% results, depending on the version of the bootloader and firmware. On some devices, the sensor may be activated again after the MIUI update.
6. Alternative solutions: if the scanner does not turn off
If none of the above methods worked, consider alternatives:
| Problem. | Possible solution | Risks. |
|---|---|---|
| The scanner is spontaneously activated. | Plug a protective film on the sensor or use a case with a thickened back panel. | Sensitivity of the sensor may be impaired by intentional use |
| Sensor physically damaged | Contact the service center to replace the sensor (cost) ~1500–2500 ₽) | With unqualified repairs, problems with the tightness of the body are possible |
| The scanner consumes a lot of charge. | Turn off background activity through Settings → Battery → Optimization | Other background processes (notifications, synchronization) may be disabled |
| MIUI does not allow the sensor to be turned off | Install custom firmware (like LineageOS or Pixel Experience) | Loss of warranty, possible bugs in the phone |
If you suspect a firmware problem, check the current version of MIUI. Go to Settings → About Phone → System Update. Sometimes fingerprint sensor bugs are fixed in new builds. For example, in Redmi 9 with MIUI 12.5, there was a known bug where the scanner continued to work after the fingerprints were deleted — it was fixed in MIUI 13.