If your POCO F6's fingerprint scanner has suddenly stopped recognizing your touch, it can lock you out of your phone and apps. This is a common hiccup with in-display sensors, but it's usually something you can fix yourself without too much trouble.
Start With a Simple Restart
Before you try anything more involved, give your phone a quick reboot. A temporary software glitch is often the culprit, and a restart clears the phone's memory and reloads all the system processes. Just press and hold the power button, tap restart, and see if the scanner behaves after it boots back up.
If the phone is completely unresponsive, you can force a restart. Press and hold the power button for about 15 seconds until you feel a vibration and see the POCO logo appear on the screen.
Check Your Finger and the Screen
This might sound obvious, but it's the most common reason for a failed scan. Make sure your finger is clean, dry, and free of any lotions, grease, or dirt. The optical sensor under the screen needs a clear image of your fingerprint ridges.
Next, take a close look at your screen protector. Cheap, thick, or poorly applied tempered glass can seriously interfere with the scanner's light. Try unlocking without the protector, or consider investing in one that's specifically marketed as "fingerprint-friendly."
Also, give the screen around the sensor area a good wipe with a soft, microfiber cloth. Smudges and fingerprints can blur the sensor's view.
Re-register Your Fingerprint
If a simple clean doesn't work, the next step is to delete your old fingerprint and add it again. Over time, small changes to your finger or a poor initial scan can cause problems.
Go to Settings > Password & security > Fingerprint unlock. Enter your PIN or password, tap on the fingerprint you're having issues with, and select "Delete." Now, tap "Add fingerprint" and follow the prompts.
When registering, press your finger down firmly and adjust its position slightly with each prompt to capture the edges. I'd recommend registering the same finger twice for better coverage.
Update Your Phone's Software
Outdated software can have bugs that affect hardware like the fingerprint sensor. POCO releases updates through HyperOS to fix these kinds of issues.
Head to Settings > About phone > HyperOS version. Tap the "Check for updates" button. If an update is available, download and install it. It's a good idea to plug in your 90W charger during this process so it doesn't run out of juice.
Boot Into Safe Mode
A misbehaving third-party app could be causing a conflict. Booting into Safe Mode temporarily disables all apps you've installed, letting you see if one of them is the problem.
Press and hold the power button until the power menu appears. Then, tap and hold the "Power off" option on your screen. A prompt to reboot to Safe Mode will pop up, tap "OK." If the fingerprint scanner works perfectly in Safe Mode, you'll need to find the problematic app by uninstalling your most recent downloads one by one.
Clear the System Cache
Corrupted temporary system files can cause all sorts of weird behavior. Clearing the cache partition is a safe way to clean these out without touching your personal data.
First, power off your POCO F6 completely. Now, press and hold the Volume Up button and the Power button at the same time. When you feel a vibration or see the POCO logo, let go of the power button but keep holding volume up until you enter Recovery Mode.
Use the volume buttons to navigate to "Wipe data" and press the power button to select it. On the next screen, choose "Wipe cache" and confirm. Once it's done, select "Reboot" to start your phone normally.
Check for App-Specific Fingerprint Settings
Is the fingerprint scanner failing only in a specific app, like your banking app? The problem might be with that app's own security settings, not your system scanner.
Open the app in question and look in its settings for biometrics or security options. Try turning fingerprint authentication off and back on again within the app. You might also need to clear that app's cache or data from your phone's main settings under "Apps."
Review Your Security and Display Settings
A couple of settings in HyperOS could be getting in the way. First, go to Settings > Always-on display & Lock screen. Make sure "Fingerprint for AOD" or similar options are enabled, as this allows the scanner to be active when the screen is off.
Also, check if you have any battery saver modes turned on. Extreme power saving modes can sometimes disable non-essential sensors. Go to Settings > Battery and switch to "Balanced" or "Performance" mode to test.
Reset All Your Fingerprint Data
If re-registering one finger didn't help, try removing all stored fingerprints and starting fresh. This gives the system a completely clean slate.
Navigate back to Settings > Password & security > Fingerprint unlock. After entering your PIN, you should see an option to delete all fingerprints. Confirm, then restart your phone. Once it's back on, go through the setup process again, adding your primary finger slowly and carefully.
Consider a Factory Reset
This is your last resort software fix, as it will erase everything on your phone. Before you do this, make absolutely sure you have a recent backup of your photos, messages, and app data.
If you're ready, you can find the option under Settings > About phone > Factory reset. The process will take several minutes. After the phone restores itself, set it up as new and test the fingerprint scanner before restoring your backup, just to rule out corrupted backup data.
