Sony A1E Series Service Manual page 22

FLOW
1-2. NO POWER U-COM FAILURE
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Check 12V_MON
no
R446 Voltage.
Is the voltage >2.6V?
yes
Check DC_MON
no
Q410 Collector Voltage.
Is the voltage >3.0V?
yes
Check DC_OFF_DET
no
R448 or P-on ucom #pin3
is >3.0V?
yes
Check P_ON_#1
no
CL418 or P-on ucom #pin12
is >3.0V?
yes
Check PGOOD_1
no
R440 Voltage.
Is the voltage >3.0V?
yes
XBR-55/65/77A1E
Check +12V_MAIN Line
(G* board).
Check Harness and
SOC BE (IC4000 on DKA).
Change IC401
Change IC401
No POWER - DDCON/LDO
Check 1.0V DDCON (IC604).
Check P_ON_#2
no
CL417 or P-on ucom #pin13
is >3.0V?
yes
Check P_ON_HL
no
CL414 or P-on ucom #pin18
is >3.0V?
yes
Check ORESETB
no
CL416 or P-on ucom #pin14
Is the voltage >3.0V?
yes
Check X_SYSTEM_RST
no
CL412 or P-on ucom #pin20
Is the voltage >3.0V?
yes
If BE_PANEL_PWR_ON_#2
no
(R441) is >3.0V
Check BL_ON
R527 or P-on ucom #pin7
Is the voltage >3.0V?
yes
END
Ucom IC401 is working OK
TROUBLE SHOOTING
Change IC401
Change IC401
Change IC401
Change IC401
Change IC401
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