Sony XBR-55X900H Service Manual page 20

2021/04/27 23:25:57 (GMT+09:00)
1.2 No Power u-com Failure
BM5 Board LCD Model
START
Check VDD
C442 Voltage.
Is the voltage >3.0V?
yes
Check TYPE_DET
CL408 or R451 Voltage.
Is the voltage 2.6±0.2V?
yes
Check OPWRSB
CL411 or R460 Voltage.
Is the voltage 0V?
yes
Check POWER_ON
CL419 or R470 Voltage.
Is the voltage >3.0V?
yes
SAFETY NOTES
no
Check 3.3V_STBY Line
(C1708, CN1700 #9pin)
no
Type Detection Circuit problem.
Check TYPE_DET Line (R445, R446).
no SOC
Muffin 5 problem
IC1000 # AP17 OPWRSB
Try AC Off and On after few minutes.
no
If #pin10 keep Low, change IC401.If #pin10
goes High few seconds and downs to Low,
Check 12.7V_MAIN Line (from G board).
SELF DIAGNOSTIC FUNCTION TROUBLESHOOTING
T R O U B L E S H O O T I N G
Check 12V_MON
R462 Voltage.
Is the voltage >2.6V?
Check DC_OFF_DET
CL414 or R465
Is the voltage >3.0V?
Check P_ON_#1
CL418
P-on u-com #pin12
(IC401)
Check PGOOD_1
CL413 or R456
Is the voltage >3.0V?
Continue next page...
SERVICE ADJUSTMENT
no
Check 12.7V_MAIN Line
and 12.7V_AUDIO Line
(from G board).
yes
no
Voltage. Change IC401
yes
no
or
Change IC401
is >3.0V?
yes
1.3 No POWER –
no
DDCON/LDO
Voltage.
Check 0.8V_M5_CORE
DDCON (IC804)
DIAGRAM
20
HANDLING GUIDE
SYS SET