VSX-LX50
66
1
2
3
4
1
2
3
4
C
D
F
A
B
E
Step 1: Connectors
Step 2: Power supply
CN701, CN702
To STEP 2
Are
the connectors
securely inserted
?
Insert the connectors
securely.
Check the patterns in
the path.
No
Yes
To STEP 1
Yes
Yes
Is there
any loose
connection
of CN702?
Check the
MOTHER Assy.
No
CN702 (pin 4)
IC703 (pin 2)
Is
the voltage
5 V ?
No
5 V input
3.3 V Regulator IC input
3-5 Converter
USB Power SW
1
2
Yes
Yes
Yes
Is IC703
abnormally
hot?
Replace IC703.
The output and GND may be
short-circuited. Check the path
between them.
No
Is
the voltage
3.3 V ?
No
Yes
Yes
Is IC702
abnormally
hot?
Replace IC702.
The output and GND may be
short-circuited. Check the path
between them.
No
Is
the voltage
1.8 V ?
No
Yes
Is
the voltage
5 V ?
No
Check the parts and
patterns in the path.
IC762 (pins 37, 47) FLASH ROM
6
Is
the voltage
3.3 V ?
No
Yes
Check the parts and
patterns in the path.
IC761 (pins 1,3,9,14,27,43,49) SDRAM
7
IC703 (pin 4), IC702 (pin 1)
3.3 V Reg. output /
1.8 V Reg. input
5
Is
the voltage
3.3 V ?
No
IC702 (pin 5)
1.8 V Regulator output
9
Yes
Check the parts and
patterns in the path.
IC701 (pins 9,26,43,65,84,85,119)
USB Media control IC
8
Is
the voltage
3.3 V ?
No
Check the parts and
patterns in the path.
IC951 (pin 5)
3
Yes
Is
the voltage
5 V ?
No
Check the parts and
patterns in the path.
IC771 (pin 5)
4
Yes
Is
the voltage
5 V ?
No
A
U
SB
T
rou
b
les
h
ooting