hi,
I m' not a specialist on android, perhaps you can :
Activate "devloppoment tools" on the phone
Activate "USB debuging"
install ADB tools on a computer
navigate to the folder where is adb
Open a commande line windows to this folder
Connect the phone to a computer
type "adb shell"
type getevent
press the figerprint sensor
you have to see something like that if the sensor is there:
add device 1: /dev/input/event6
name: "bengal-idp-snd-card Button Jack"
add device 2: /dev/input/event5
name: "bengal-idp-snd-card Headset Jack