Sony KD-55X8 G Series Service Manual page 24

1.2 No Power u-com Failure
BSL Board Model
START
no
Check VDD
C506 Voltage.
Is the voltage >3.0V?
yes
no
Check TYPE_DET
R428 Voltage.
Is the voltage 2.6±0.2V?
yes
no
Check OPWRSB
CL405 Voltage.
Is the voltage 0V?
yes
no
Check POWER_ON
R526 or P-on u-com #pin10 (IC401)
Is the voltage >3.0V?
yes
Check 3.3V_STBY Line (L402, CN400 #14pin)
Type Detection Circuit problem.
Check TYPE_DET Line (R521, R522).
SOC
Muffin 3 problem
IC1000 # AL14 OPWRSB
Try AC Off and On after few minutes.
If #pin10 keep Low, change IC401.
If #pin10 goes High few seconds and downs to Low,
Check +12V_MAIN Line (from G board).
TV Business Division
no
Check 12V_MON
R426 Voltage.
Is the voltage >2.6V?
yes
Check DC_OFF_DET
no
R448 or
P-on u-com #pin3 (IC401)
is >3.0V?
yes
Check P_ON_#1
no
CL418 or
P-on u-com #pin12 (IC401)
is >3.0V?
yes
no
Check PGOOD_1
R434 Voltage.
Is the voltage >3.0V?
Continue next page...
Check 12.7V_MAIN Line
(from G board).
Change IC401
Change IC401
1.3 No POWER - DDCON/LDO
Check 1.0V DDCONs
(IC608, IC609, IC610)
(Supplementary
24
information)