Motorola Moto X Force Troubleshooting Manual page 72

Ambient Light Sensor (ALS) Troubleshooting
ALS Sensor is the same part as Proximity Sensor (U6120).
•
If reading is failing:
•
– Check black grommet in housing is not obscuring the top
of the part
– Inspect opening in lens. It should be translucent when
holding front housing up to a light. Try swapping front
housings.
Try replacing U6120
–
Test on different fixture, bulbs in fixture may be too old
–
and dim.
• If no reading at all (error code):
Check part orientation of U6120
–
Verify voltage at C6121 is 2.85V
–
– Verify voltage at R6000 and R6001 is 1.8V
MOTOROLA CONFIDENTIAL
If voltage is missing try replacing U6120, U6000, or
•
U2000 in that order
Moto X Force/DROID Turbo 2
BASEBAND TROUBLESHOOTING GUIDES