If your Sony Xperia 1 VI's fingerprint scanner is acting up, you're locked out of one of the fastest ways to unlock your phone. The side-mounted sensor is convenient, but when it stops responding, it's a real hassle. Let's get it working again.
Start With a Simple Restart
Before anything else, give your phone a fresh start. Press and hold the Power button and the Volume Up button together for about ten seconds. You'll feel it vibrate and then restart. This clears out any temporary software glitches that might be confusing the sensor.
Once it's back on, try unlocking with your fingerprint. I've found this fixes the issue more often than you'd think, especially if the problem just started out of the blue.
Check Your Finger and the Sensor
The sensor on the Xperia 1 VI is built into the power button on the right side. Take a close look at it. Is there any dirt, lint, or grease on that small strip? Your own finger matters just as much.
Make sure your fingertip is clean and completely dry. Even a little moisture from hand sanitizer or sweat can prevent a good read. Gently wipe both your finger and the sensor with a soft, dry cloth.
Re-register Your Fingerprint
If a simple clean doesn't do it, the next step is to delete your old fingerprint and teach the phone your print again. Head into your settings and go to Security & privacy > Device unlock > Fingerprint.
You'll need to enter your PIN, pattern, or password to proceed. Tap on the fingerprint you're having trouble with and select Delete. Now, tap Add fingerprint and follow the prompts.
When you're scanning, pay close attention to the on-screen guide. Cover the entire pad of your finger, rolling it slightly to get the edges. Don't lift your finger too quickly between scans.
Update Your Phone's Software
Outdated software can cause all sorts of weird behavior, including biometric failures. Sony may have released a fix for a sensor bug you're experiencing. To check, go to Settings > System > Software update.
Tap Check for update. If one is available, download and install it. It's a good idea to plug your phone into a charger during this process. I'd recommend using a 30W USB-PD 3.0 charger to make it quick, since the phone doesn't come with one in the box.
Boot Into Safe Mode
Sometimes, a third-party app you installed can interfere with system functions like the fingerprint reader. Booting into Safe Mode temporarily disables all those downloaded apps.
To do this, press and hold the Power button until the power menu appears. Then, tap and hold the Power off option on your screen. You'll get a prompt to reboot to Safe Mode. Tap it.
If your fingerprint scanner works perfectly in Safe Mode, you know a downloaded app is the culprit. You'll need to restart normally and then uninstall apps one by one to find the offender, starting with any recent security, launcher, or lock screen apps.
Clear the System Cache Partition
This is a deeper clean that doesn't touch your personal data. It clears out temporary system files that might have become corrupted. First, power your Xperia 1 VI off completely.
With the phone off, press and hold the Volume Down button and the Power button at the same time. Keep holding them until you feel a vibration, then release. You should see the Sony logo and then a black screen with small text.
Use the Volume buttons to navigate to Wipe cache partition and press the Power button to select it. Confirm the action. Once it's done, select Reboot system now.
Check for Screen Protector Interference
This is a common one. A poorly fitted screen protector or a case with a high lip can physically block your finger from making proper contact with the side sensor. The sensor needs a clean, direct touch.
Try removing your case for a moment. If you have a screen protector that wraps around the edges, see if it's lifting near the power button. Sometimes, just pressing down firmly on the protector around the sensor area can help, but a replacement might be necessary.
Register Multiple Fingers
Don't just register one finger. Add at least two, like your right and left thumb or index fingers. Go back to Security & privacy > Device unlock > Fingerprint and tap Add fingerprint again.
This gives you a backup if one finger is dirty, damp, or has a small cut. It also helps the system build a better understanding of your prints. I always register my primary thumb twice from slightly different angles for better reliability.
Review Your Security Settings
There's a setting that requires your primary PIN, pattern, or password after a restart or a certain period of inactivity. This is a security feature, not a bug. You can check this by going to Security & privacy > Device unlock > Fingerprint.
Look for an option like "Fingerprint unlock after restart." If it's enabled, you'll always need your PIN first after rebooting the phone. This is normal and expected behavior.
Consider a Factory Reset
This is the last resort before thinking about hardware. A factory reset will wipe your phone back to its original out-of-the-box state. You must back up everything important first, photos, messages, app data, to Google Drive or a computer.
To perform the reset, go to Settings > System > Reset options > Erase all data (factory reset). Follow the prompts. After the phone restarts, set it up as new and immediately test the fingerprint sensor before restoring your backup. If it works now, the problem was a deep software corruption.