Sony XR-55A95K Service Manual page 19

TROUBLESHOOTING
1.2 No Power U – com Failure
BM5S22 Board OLED Model when Mounted on IC420
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Check P_ON_#2
no
CL417 or
P-on u-com #pin17 (IC420)
is >3.0V?
yes
Check P_ON_HL
no
CL415 or
P-on u-com #pin10 (IC420)
is >3.0V?
yes
Check ORESETB
no
CL416 or
P-on u-com #pin16 (IC420)
Is the voltage >3.0V?
yes
Check AC_OFF_DET
no
_OUT CL404 or
P-on u-com #pin2(IC420)
Is the voltage >3.0V?
yes
Change IC420
Change IC420
Change IC420
Check "AC_OFF_DET_OUT"
(CL404 or CL5221 from IC5000)
Check "AC_DET_IN"
(JL1707, R1704 or CN1700 #16pin from
G board)
no
Check X_BL_MUTE
CL412 or R459 Voltage.
Is the voltage >3.0V?
yes
Check BL_ON no
CL420 or R471 Voltage.
Is the voltage >3.0V?
yes
END
u-com IC420 is working OK
Check "X_BE_RST" (from SOC Muffin).
*If X_BE_RST is >3.0, SOC BE(IC5000) problem.
Otherwise, SOC Muffin 5 (IC1000) problem.
Change IC420
19
SYS SET