Sony KD-55X8 G Series Service Manual page 97

5.2 Light Sensor Error
Backlight level does not
change when ambient
light changed
Check UI setting and
make sure light sensor
setting is "ON"
Setting is "OFF"
Setting issue
Change setting to "ON"
Fuse continuity
F1201/F1204
Open  NG
Short  OK
Resistor value
R1280 : 150k [ohm]
TV Business Division
Check harness
Setting is "ON"
connection between
B-board and Smart
Core harness
NG
Change harness
between B-board to
Smart Core harness
NG
Change Smart Core
NG
Check Fuse continuity
condition
OK
Check resistor value on
B-board
OK
97
OK
Harness connection
issue
OK
B-board to Smart Core harness
issue
OK
Smart Core issue
NG
Parts issue
NG
Parts issue
Change B-board
Main device issue
97