The Galaxy A54 5G unlocks with an under-display fingerprint sensor and with face recognition, and unlock failures have mostly simple causes. For the fingerprint, clean the screen and your finger, press firmly and cover the sensor area, and remove any screen protector that is not designed for an under-display sensor, because a thick or air-gapped protector blocks the reading. If it fails often, delete the fingerprints and add them again, adding the same finger several times with different pressure, and add the finger twice for a better match. Wet, cold or dry fingers read poorly.
Face recognition is less secure than the fingerprint and fails in poor light, so keep it for convenience. After an update, the sensor can need a restart. If the sensor fails with a clean bare screen and fresh enrolments, the hardware may need service.
The checks in more detail
The A54's fingerprint sensor sits under the screen near the bottom, so place the fingertip on the marked area and not higher up, and press with the flat of the finger rather than the tip. Set up a second copy of the same finger in a different grip, because the sensor reads best when it sees a larger area. On the A54 the sensor is an optical one under the display, which lights the screen to read the print, so it needs the area to be bright and unobstructed; in a dark room or with the screen's brightness at the minimum the reading is weaker.
Set Auto brightness on, and keep the finger flat, since the optical sensor looks at a picture of the print and not at the ridges' sound reflection.
Differential
Likely causes of “Samsung Galaxy A54 5G biometric unlock is not working”, and how to tell them apart
- 1
A dirty screen or wet finger
What separates it Unlock fails often
How to confirm Wipe the screen and dry the finger
- 2
A protector over the sensor
What separates it Unlock stopped after fitting one
How to confirm Remove it and test
- 3
A weak enrolment
What separates it Only some touches work
How to confirm Delete and re-add the fingerprint several times
- 4
A software fault
What separates it It stopped after an update
How to confirm Restart and update
- 5
A damaged sensor
What separates it It fails on a clean bare screen
How to confirm Contact Samsung
Before you touch a setting
Record this first — changing settings destroys the evidence
- Whether a protector is fitted
- How many fingerprints are enrolled
- Whether face unlock works
- Whether it began after an update
Try in this order
0 of 10 completedClean the screen and your finger
ReversibleWith a soft cloth.
Remove the protector
ReversibleTest the bare screen.
Press firmly over the sensor
ReversibleHold until it unlocks.
Delete and re-add the fingerprint
ReversibleSettings, Security and privacy, Biometrics.
Add the same finger twice
ReversibleFor a better match.
Restart and update
ReversibleInstall the latest update.
Place the finger on the marked area
ReversibleUse the icon shown on the lock screen and press with the flat of the finger.
Add a second print of the same finger
ReversibleEnrol the finger again in a different grip, so the phone learns more of its pattern.
Check the display's brightness
ReversibleIn bright sun the sensor may struggle, so shade the screen.
Enrol under normal lighting
ReversibleAdd the fingerprint in a moderately lit room, not in sunlight or in the dark, so that the optical sensor learns a clean picture.
Model-specific
What is true of this model and not of its siblings
- Protectors
- They can block an under-display sensor.
- Enrol twice
- A second copy helps.
- The sensor area
- It is a small area low on the screen.
- Two copies
- A second enrolment of the same finger improves matching.
- Sun
- Strong light interferes with an optical sensor.
- An optical sensor
- The A54 reads a picture of the print, so light and a clean glass matter more than pressure.
- Optical, not ultrasonic
- The Galaxy A54 uses an optical fingerprint reader under the screen, which takes a photograph of the finger lit by the display, so it needs a dry, clean finger and a protector that is thin and clear. A thick protector or one with a tint reduces the picture. Press firmly on the lit area and keep still for a moment, because a moving finger blurs the image.
Stop boundary
When this stops being a self-service repair
- !If the sensor fails on a bare screen with fresh enrolments, contact Samsung
- !If face unlock also fails, ask Samsung
- !Use the PIN meanwhile
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why does my A54 fingerprint fail?+
A dirty screen, a protector or a weak enrolment.
Is face unlock as secure?+
No, the fingerprint is more secure.
Can I use a PIN?+
Yes.
Does a protector matter?+
Yes.
Where is the fingerprint sensor?+
Under the screen near the bottom.
Can I add more fingers?+
Yes, several.
Does the A54 use an ultrasonic reader?+
No, an optical one under the display.