A fingerprint sensor not working is usually fixed in a few minutes. Clean the sensor, dry your finger, then delete your saved prints and add them again. On phones with the sensor under the screen, a thick screen protector is the most common cause.
This guide covers Android phones such as Tecno, Infinix, Samsung and Xiaomi, plus iPhones and iPads with Touch ID. Start with Fix 1 and stop as soon as your sensor works.
Why Is My Fingerprint Sensor Not Working?
Most fingerprint failures come from dirt or moisture, a screen protector, old saved prints, or a software glitch. A hardware fault is the least likely cause.
So work through the fixes below in order. The early ones take seconds and solve most cases. The later ones take longer, and you only need them if the quick fixes fail.
Fix 1: Clean the Sensor and Dry Your Finger
Oil, sweat, dust and hand cream sit between your skin and the sensor. As a result, the phone cannot read your print clearly.
First, wipe the sensor with a soft, slightly damp cloth, then dry it. Next, wash and fully dry your hands. Wet fingers are the biggest cause of “fingerprint not recognised”, especially in hot, humid weather.
Fix 2: Check the Screen Protector
If your fingerprint sensor stopped working after you fitted a new screen protector, the protector is almost certainly the cause.
Most in display sensors are optical. They take a picture of your print through the glass. A thick, cheap or bubbled protector blurs that picture. Ultrasonic sensors, used on top Samsung models, are even more sensitive.
To test it, peel the protector off and try the sensor. If it works, buy a thin protector labelled fingerprint compatible. After fitting it, delete your prints and add them again through the new layer. On Samsung, also turn on Touch sensitivity under Settings, then Display.
Fix 3: Delete and Add Your Fingerprints Again
Your skin changes with weather, work and small cuts. Over time, the saved print stops matching well. A fresh setup fixes slow or failing recognition more often than any other step.
- Open Settings, then Security or Biometrics, then Fingerprint.
- Delete every saved fingerprint.
- Restart the phone.
- Add your finger again. Press with the flat pad, not the tip.
- Move your finger slightly between touches, so the phone records the edges too.
For better results, add the same finger twice as two separate prints. This helps budget in display sensors in particular.
Fix 4: Restart and Update the Phone
A restart resets the fingerprint service when it freezes. Then check for a software update under Settings, then System or About phone. Phone makers often fix fingerprint bugs in updates, and this includes HiOS on Tecno and XOS on Infinix.
Fix 5: Rule Out a Problem App
If the sensor stopped working after you installed an app, restart in Safe Mode. On most Android phones, hold the power button, then press and hold Power off until Safe Mode appears.
If the sensor works in Safe Mode, a recent app is to blame. Remove recent installs one at a time until it works again. Finally, if nothing helps, back up your phone and try a factory reset. If the sensor still fails after that, the fault is in the hardware.
Fix 6: Fingerprint Sensor Not Working After a Screen Repair
If your fingerprint sensor is not working after a screen replacement, the new screen is usually the reason.
In display sensors are tuned to the original screen. A low quality replacement, or one fitted without setup, can block the sensor for good. In that case, go back to the repairer. Ask for a better quality panel and for the sensor to be set up again. On some models, only an original screen brings the sensor back.
Before any future screen repair, ask one question first: will the fingerprint still work with this screen?
Touch ID Not Working on iPhone or iPad
Newer iPhones use Face ID. However, Touch ID is still found on older iPhones with a Home button and on many iPads. If yours has Touch ID, try these steps in order:
- Update to the latest iOS or iPadOS.
- Clean and dry your finger and the sensor.
- Cover the whole sensor, including the metal ring. Hold still during the scan.
- Make sure your case or screen protector does not cover the sensor or ring.
- Open Settings, then Touch ID and Passcode. Check that iPhone Unlock is on and that a print is saved.
- Delete your prints, restart and add them again, or try a different finger.
Note that Touch ID usually stops working if the Home button was replaced outside Apple. That is because each sensor is paired to its own device. In that case, only Apple or an authorised service centre can help.
When It Is a Hardware Fault
If the sensor still fails after cleaning, a fresh setup, an update and a reset, the part itself is faulty. Rear and power button sensors are cheap to replace at a good repair shop. In display sensors, on the other hand, are part of the screen, so the fix usually means a quality screen replacement.
For Infinix phones, use our Infinix fingerprint fixes guide, which covers the screen lock setting that hides the fingerprint option.
Common Questions
Why does my fingerprint sensor work sometimes and fail other times?
This usually means moisture, a poor screen protector or a thin setup. Add the same finger twice as separate prints and keep your fingers dry.
Does a screen protector stop the fingerprint sensor?
It can. Thick or low quality protectors blur optical sensors and block ultrasonic ones. Use a thin, fingerprint compatible protector and set up your prints again through it.
Is fingerprint unlock safe?
Yes, for everyday use. Keep a strong PIN as a backup, since the phone falls back to it whenever the sensor fails. For office clock in machines, see our guide to improving fingerprint recognition at work.
Fix a Fingerprint Sensor Not Working in Order
When your fingerprint sensor is not working, clean it first, then check the screen protector and set up your prints again. Next, restart and update the phone. Only treat it as a hardware fault once every other step has failed. For Touch ID devices, Apple’s guide if Touch ID isn’t working lists the official steps.
If your Android phone also feels slow or drops its connection, our guides to speeding up an Android phone and fixing Android network problems can help.
Frenzy valentine is a passionate blogger, developer, and entrepreneur. He is the founder and author of myfreshgists.com.