Fingerprint sensor not working while charging phone

👤 Diwas Poudel    🕒 11 Sep 2023    📁 FIX

The fingerprint is the user's first choice for unlocking their phone, authenticating mobile payments, authorizing purchases, and unlocking applications by simply placing their finger into the sensor.

You may sometimes have noticed that when you charge your phone and try to use the fingerprint sensor for locking and unlocking your phone, it does not work. Sometimes it works after several attempts, and sometimes it stops due to too many attempts and forces you to unlock using an alternative such as a pattern lock or password, face recognition, etc. Again when you unplugged the phone from the charger, it started working again. So, let's take a look at what might be affecting the fingerprint sensor while it's charging.

It is important to note that the majority of smartphones use capacitive fingerprint sensors. Electricity is used by capacitive sensors to determine fingerprint patterns. When you place your finger on the sensor, it measures the charge, then the ridges exhibit a change in capacitance, and these data are mapped out prints, allowing you to unlock/lock and authenticate.

Reason for the fingerprint sensor problem while charging phone

Let's discuss some of the reasons:

1 Irregular power supply 

Due to fluctuations in power supply, you may experience any sensor of your phone stopping working and tapping randomly, as well as the fingerprint sensor ceasing to function.

Sometimes poor isolation between the components can also cause the problem.

Apple Forum also talks about it Read here

2 Using a non-standard charger.

Nonstandard chargers may not be able to deliver the proper amount of power and current to the sensor, which could be the cause.

3 Using nonstandard USB Cable /Thunderbolt cable 

When using a nonstandard USB cable, the required specifications for a capacitive sensor, such as a fingerprint sensor, are not always met.

4 Dirt, Dry, Oily

 When your finger is wet, dry, dirty, or oily, the fingerprint sensor does not work properly.

5 Not calibrate properly 

The fingerprint sensor needs to be calibrated properly to make it work. If not calibrated properly then it may not read your fingerprint.

To get rid of these problems here are some solutions.

1 Always connect your charger to a stable and clean power supply where the voltage does not fluctuate.

2 It is always recommended to use the original charger supplied by the manufacturer. In addition, if the charger is damaged, always purchase the charger from the verified retailer showroom.

3 Always use the standard original USB cable and Thunderbolt cable that came with your smartphone when you purchased it. Also try testing with different standard USB cables.

4 Before attempting to use the fingerprint sensor, clean your finger.

5 Restart your phone; hardware and software glitches can also be the source of the problem.

6 Update your fingerprint sensor software on a regular basis if provided via software updates.

7 If the same problem repeats and becomes worse then you can take it to the repair center. 

8 Also you can recalibrate fingerprint sensors.

9 You can try restoring the phone to factory settings.

10 Also you can try restarting your phone sometimes this might fix the issue.

11 Call the official phone help desk if the problem is getting worse.

Limitation of Fingerprint Sensor

Some of the limitations are They can be fooled by AI fingerprints, they can be slow to respond and can be affected by environmental factors.