If your OnePlus Open's fingerprint sensor suddenly stops responding, it can lock you out of your phone and apps. The good news is this is usually a software hiccup or a simple fix you can handle yourself. Let's get it working again.
Clean the Sensor and Your Finger
This is the most common fix. The optical fingerprint sensor on the OnePlus Open's power button needs a clean surface to read your print. Gently wipe the power button area with a soft, dry microfiber cloth. Any dirt, oil, or moisture on your finger or the sensor can block the scan.
Make sure your finger is completely dry. If you've just washed your hands, lotioned up, or your hands are sweaty, the sensor will likely fail. I'd start with this simple clean and dry check every time.
Restart Your OnePlus Open
A quick restart clears out temporary software glitches that can affect the sensor. Just press and hold the power button for about 10 seconds until you feel it vibrate and the screen goes black. Release the button and wait for it to boot back up.
This force restart method works whether your phone is frozen or not. Once it's back on, try unlocking with your fingerprint again.
Re-register Your Fingerprint
If a simple restart doesn't do it, the next step is to delete and re-add your fingerprint. Over time, small changes to your finger or a poor initial scan can cause recognition to fail.
Open Settings and go to Password & security > Fingerprint. You'll need to enter your PIN or password to proceed. Tap on the fingerprint you're having trouble with and select Delete.
Now, tap Add fingerprint. Follow the on-screen prompts closely, making sure to roll your finger to capture the edges and tip. Press a little firmer than you think you need to. A good, thorough registration makes all the difference.
Check for a Software Update
Outdated software can have bugs that break features like the fingerprint sensor. OnePlus regularly releases updates through OxygenOS to fix these kinds of issues.
Go to Settings > About device > OxygenOS version and tap on the top banner to check for an update. If one is available, download and install it. Make sure your phone is connected to Wi-Fi and has at least a 50% charge, or better yet, plug in the included 67W SUPERVOOC charger.
Examine Your Screen Protector
This is a big one for foldables. A poorly installed or thick screen protector on the outer display can physically cover the power button/fingerprint sensor area, preventing it from reading your print.
Look closely at the edges of your screen protector near the power button. If it's peeling, bubbled, or too thick, it might be the culprit. You may need to carefully remove it or have it replaced with a model known to be compatible.
Also, be mindful of the inner screen. While the sensor isn't there, pressing the crease with fingernails or sharp objects can cause damage that might affect other components.
Boot Into Safe Mode
A third-party app you installed could be causing a conflict. Booting into Safe Mode temporarily disables all downloaded apps, 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 until you see a prompt to reboot to Safe Mode. Tap it.
If the fingerprint sensor works perfectly in Safe Mode, you know a downloaded app is to blame. You'll need to restart normally and uninstall apps one by one, starting with the most recent, to find the offender.
Clear the System Cache
Corrupted system cache data can cause all sorts of strange behavior. Clearing it won't delete your personal files, but it can resolve underlying software issues.
First, turn off your OnePlus Open completely. Then, press and hold the Volume Down and Power buttons together until the OnePlus logo appears. This will boot you into recovery mode.
Use the volume buttons to navigate to Wipe data and cache and press the power button to select. Then, choose Wipe cache and confirm. Once it's done, select Reboot.
Consider the Hinge and Environment
The OnePlus Open's folding mechanism is complex. While it's not a common cause for sensor failure, significant dust accumulation in the hinge over time could potentially interfere with internal connections.
It's good practice to gently clean the hinge area regularly with compressed air to prevent debris buildup. Also, extreme temperatures, very hot or very cold, can temporarily affect the sensor's performance. Let your phone return to a normal room temperature and try again.
If you've worked through all these steps and the sensor is still dead, and you've confirmed it doesn't work in Safe Mode either, the issue may be physical. The fingerprint sensor is integrated into the power button assembly. In that case, contacting OnePlus support for a repair diagnosis would be the next step.
