Sony A1E Series Service Manual page 24

FLOW
1-3. NO POWER DDCON/LDO
DDCONs CHECK
START
Check fuse
no
F4xx / F40xx/F6xx
Is fuse OK?
yes
Check Vcc voltage
no
C4xx / C40xx/C6xx
Is voltage >12.0V?
yes
Check Enable pin
no
voltage
Is voltage >2.5V?
yes
Change DDCON IC
XBR-55/65/77A1E
Change Fuse
1) Check POWER_ON P-on ucom #pin10
(Refer No Power U-Com Failure)
2) Check G* board
3) Check IC9000 on JK* (only AC-ADP Models)
1.2 No Power U-Com Failure
or
Enable source
Board IC Ref Voltage supply
BKA IC402 +5.0V_VBUS/+5V_MAIN
BKA IC403 +3.3V_MAIN
BKA IC405 +1.8V_TU
BKA IC601 +1.5V_DDR
BKA IC604 +1.0V_M2
DKA IC401 +3.3V_MAIN
DKA IC4001 +1.5V_BE
DKA IC4002 +1.1V_BE
DKA IC4003 +1.0V_BE
LDOS CHECK
START
Check Vcc voltage
no
C4xxx or C6xx
Is voltage >3V?
yes
Check Enable pin
no
voltage
Is voltage >3V?
yes
Change LDO IC
TROUBLE SHOOTING
Check +3.3V_DDC_OUT
DDCON (IC403 on BKA / IC401 on DKA)
or
+3.3V_STBY (G* board)
No Power U-Com Failure
or
Enable source
Board IC Ref Voltage supply
BKA IC602 +1.05V_M2_STBY
BKA IC603 +1.05V_M2_A_1
BKA IC605 +1.05V_M2_ST_ET
BKA IC606 +1.05V_M2_A_2
BKA IC607 VCC3IO_EMMC (1.8V)
DKA IC4004 +1.8V_BE
24