Sony XBR-55X850D Service Manual page 21

FLOW
1-1. NO POWER
Case: BMFW2 structure
with G* board
No Power
Check STBY 3.3V
NG
C9006
near CN9000
on B* board
OK
B* Board
XBR-55X850D/855D/857D, 65X850D/855D/857D, 75X850D/855D/857D
Replace
NG
Between G* Board to G* Board
B* Board Harness
OK
Harness
u-Com Failure
DDCON/LDO
Main Device Failure
with AC-ADP
No Power
Check 19.5V
NG
C9001
Between LD Board to
near CN9000
B* Board Harness
on B* board
OK
B* Board
TROUBLE SHOOTING
Replace LD Board
NG
or
AC Adaptor
OK
Harness
u-Com Failure
DDCON/LDO
Main Device Failure
21