The Galaxy Note20, released in 2020, was one of the last Note phones, and it has an in-display ultrasonic fingerprint sensor and face recognition, with the S Pen as its signature, so unlock problems six years on tend to come from age: a registration that has worn, a protector, a replaced screen or a battery that has begun to swell. Start with the sensor, which sits under the lower middle of the 6.7 inch display. Clean the screen and your finger, take off any protector, since an ultrasonic sensor needs a clear contact, and test. If it works without the protector, choose one designed for ultrasonic sensors, and register the fingerprint again afterwards.
The checks in more detail
A cracked screen or a bubble over the sensor stops it reading. Open Settings, Biometrics and security, Fingerprints, enter the PIN and delete a print that fails often, then register it again, pressing flat and covering the whole sensor, and register the same finger twice at different angles with a second finger as a backup. Check that Unlock phone is on. Face recognition, in the same menu, is less secure and works worse in dim light. If you replaced the screen, an uncalibrated display can stop the sensor enrolling prints; Samsung can calibrate it. The Note20 is old enough that its software support has ended, so no new fixes arrive, and its battery may be weak.
A swollen battery can lift the display and press on the sensor layer, causing unlock problems and a screen that lifts at the edges; if you see that, stop using the phone and have it repaired. Restart the phone, and run Samsung Members diagnostics. If you plan to keep the phone, back it up and consider a battery replacement, which also cures many odd behaviors. Contact Samsung or a repairer with the serial number if the sensor fails after these steps. Keep the PIN safe, since it is the fallback.
The Note20 has a flat 6.7 inch screen with a plastic back and the S Pen slot at the bottom, and owners sometimes find the fingerprint problem began after the S Pen was dropped on the screen or the phone was dropped on a corner, because a hit at the bottom edge can damage the display layers above the sensor. Check the screen for a pressure mark or a faint line near the lower middle. Because the Note20 is the base model of its line, its display is not the highest-end one, and its sensor is the same type as the S20's. If an S Pen is in use, keep its tip off the sensor area when registering fingerprints.
Differential
Likely causes of “Samsung Galaxy Note20 biometric unlock is not working”, and how to tell them apart
- 1
A swollen battery pressing on the display
What separates it The screen lifts and unlock fails
How to confirm Stop using the phone and repair it
- 2
Old software
What separates it No new fixes
How to confirm Back up and consider replacing the battery
Before you touch a setting
Record this first — changing settings destroys the evidence
- Whether the screen is lifting
- The battery's age
Try in this order
0 of 3 completedClean the screen and finger
ReversibleRemove the protector.
Check for a lifting screen
ReversibleSwollen battery.
Contact Samsung
ReversibleIf it fails.
Model-specific
What is true of this model and not of its siblings
- Older phone
- Hardware aging matters.
- S Pen
- The Note20's signature feature.
Stop boundary
When this stops being a self-service repair
- !Stop using a phone with a swollen battery
- !If the sensor fails after these steps, contact Samsung or a repairer with the serial number
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Is the phone still supported?+
Its software support has ended.
Can the battery cause it?+
A swollen battery can.
Will a different screen protector bring the Note20 reader back?+
Only a protector designed for in-display ultrasonic readers should be used. One that is thick, or has air under it over the sensor area, can stop the reader, so test without it first, then fit a suitable one and register the finger again.