Sony KD-49X9 F Series Service Manual page 16

1.2 No Power u-com Failure
CU Segment / LCD 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
R443 Voltage.
Is the voltage 0V?
yes
no
Check POWER_ON
R526 or P-on u-com #pin10
Is the voltage >3.0V?
yes
Check +3.3V_STBY Line (C408, CN400 #9pin)
Type Detection Circuit problem.
Check TYPE_DET Line (R521, R522, R523).
SOC
Muffin 2
problem
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).
no
Check 12V_MON
R446 Voltage.
Is the voltage >2.6V?
yes
no
Check DC_OFF_DET
R448 or P-on u-com #pin3
is >3.0V?
yes
no
Check P_ON_#1
CL418 or P-on u-com #pin12
is >3.0V?
yes
no
Check PGOOD_1
R440 Voltage.
Is the voltage >3.0V?
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Check +12V_MAIN Line
(from G board).
Change IC401
Change IC401
1.3 No POWER - DDCON/LDO
Check 1.0V DDCON (IC604)
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