Sony XR-55A75L Service Manual page 33

TROUBLESHOOTING
1.3 No Power DDCON/LDO (DDCON Check)
START
Check fuse no
F6xx/F8xx
Is fuse OK?
yes
Check Vcc voltage no
C4xx / C6xx/C8xx
Is voltage >12.0V?
yes
no
Check Enable pin
voltage
Is voltage >2.5V?
yes
Change DDCON 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 30 for Ref Number.
Board Operation IC Ref Voltage supply
DC/DC IC418
DC/DC IC600 5V_MAIN/5V_AUDIO
DC/DC IC618
DC/DC IC613 5.0V_VBUS_CAMERA
DC/DC IC804 0.8V_M5_CORE
DC/DC IC813
DC/DC IC812
BM5STY DC/DC IC810 0.8V_M5_CPU
DC/DC IC811 0.8V_M5_GPU
DC/DC IC4800 1.8V_BE_DDC
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
5.0V_STBY_H
3.3V_MAIN
1.8V_M5
1.0V_M5
1.1V_BE
0.8V_BE
0.7V_BE
33
SYS SET