Pioneer VSX-918V-S Service Manual page 38

1
QQ
3 7 63 1515 0
A
A
11
IC331 (pin 14)
5 V to 3 V Converter
Is
No
the voltage
3.3 V ?
Yes
12
IC401 (pins 16, 33, 64, 76, 112)
B
Is
No
the voltage
3.3 V ?
Yes
13
IC402 (pin 5)
1.8 V Regulator output
Is
No
the voltage
1.8 V ?
C
Yes
TE
L 13942296513
14
IC401 (pins 7, 24, 41, 71, 77, 87, 109, 119)
Is
No
the voltage
1.8 V ?
Yes
D
IC471 (pin 1)
15 USB Power SW output
Is
No
the voltage
5 V ?
Yes
E
CN401 (pin 1)
16 USB Bus power
Is
No
the voltage
5 V ?
www
Yes
Power supply is OK.
To STEP 3
F
38
1
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2
Check the parts and
patterns in the path.
USB Media control IC
Check the parts and
patterns in the path.
Is IC402
No
abnormally
hot?
Yes
Replace IC402.
The output and GND may be
short-circuited. Check the path
between them.
USB Media control IC
Check the parts and
patterns in the path.
Is pin 20
No
Is pin 4 [USB
(CTL) of CN3*,
CTL] of IC471
CN7** high?
high?
Yes
Check the parts and
Replace IC471.
patterns in the path.
Check the parts and
patterns in the path.
x ao
y
. i
VSX-918V-K
2
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3
8
Q Q
3 6 7 1 3
No
Check the
MAIN Assy.
Yes
u163
* VSX-918V (AWX8977)
** VSX-818V (AWX9164)
.
3
4
2 9 9 4 2 8
1 5 0 5 8 2 9 9 4
m
co
4
9 9
2 8 9 9