Sony XR-55A75L Service Manual page 35

TROUBLESHOOTING
1.3 No Power DDCON/LDO (DDCON Check) – XR-83A80*
START
Check fuse no
F4xx / F6xx/F8xx/F48xx
Is fuse OK?
yes
Check Vcc voltage no
C4xx / C6xx/C8xx/C48xx
Is voltage >12.0V?
yes
no
Check Enable pin
voltage
Is voltage >2.5V?
yes
Change DDCON
or LDO IC
Change Fuse
1) Check POWER_ON P-on u-com IC401 #pin10
(Refer 1.2 No Power U-Com Failure)
2) Check G-board
1.2 No Power U-Com Failure
or
Enable source
Please Refer page 31 for Ref Number.
Board Operation IC Ref Voltage supply
DC/DC IC600 5V_MAIN/5V_AUDIO
3.3V_MAIN/3.3V_AU
DC/DC IC601
DC/DC IC804 0.8V_M5_CORE
DC/DC IC807
DC/DC IC808
DC/DC IC810 0.8V_M5_CPU
BM5S21
DC/DC IC811 0.8V_M5_GPU
DC/DC IC4800
DC/DC IC4801
DC/DC IC4802 0.9V_BE_DDC_1
DC/DC IC4803 0.9V_BE_DDC_2
DC/DC IC4809
DC/DC IC4810
DIO
1.8V_M5
1.0V_M5
1.8V_BE_DDC
1.1V_BE
0.8V_BE
0.7V_BE
35
SYS SET