Pioneer VSX-918V-K Service Manual page 28

1
Step 5: 5 V to 3 V conversion
IC331
A
Do
No
convert 5 V into
3 V for input?
Yes
To Step 6
Step 6: X'tal
IC261 (Pin 2)
B
Is there
No
a 24.576 MHz
output?
Yes
IC261 (Pin 7)
Is there
No
a 24.576 MHz
output?
C
Yes
IC261 (Pin 5)
Is there
No
a 24.576 MHz
output?
Yes
To Step 7
D
E
F
28
1
2
Replace IC331.
Replace IC261 or X261.
Check the path to pin 45 of IC201.
Replace IC201.
Check the path to pin 30 of IC101.
Replace IC101.
2
3
Step 7
When the COAX, OPT or USB is input, go to Step 7-1.
When the HDMI is input, go to Step 7-2.
Step 7-1: DIR
Check that the S/PDIF signal is output.
Check that changes by pulling out and inserting the
digital input lines.
IC101 (Pins 1, 3)
Can
observe the
digital signal
?
(0 V ⇔ 4 V)
Yes
IC101 (Pin 42)
Can
observe the
digital signal
?
(1.65 V center, amplitude more than 0.2 Vp-p)
Yes
Check that it changes in the Playback and Pause modes of
the USB (iPod).
IC101 (Pin 5)
Can
observe the
digital signal
?
(0 V ⇔ 3.3 V)
Yes
Check that the data and clock signals are output.
IC101 (Pin 27)
Is there
a master clock
output?
(0 V ⇔ 3.3 V)
Yes
IC101 (Pin 24)
Is there
a LR clock
output?
(0 V ⇔ 3.3 V)
Yes
IC101 (Pin 25)
Is there
a data
output?
(0 V ⇔ 3.3 V)
Yes
A
VSX-918V-K
3
4
OPTICAL
No Check the DIGITAL INPUT Assy,
and parts and patterns in the path.
COAX
No
Check the parts and patterns
in the path.
From USB Block
No
Check the USB Block, and the parts
and patterns in the path.
DIRM (Master clock)
Is the
No
No
voltage of PDN
IC101-pin 31
5 V?
Check the other assy.
(surrounding of the
microcomputer)
Replace IC101.
DIRL (LR clock)
No
Replace IC101.
DIRD (Data)
No
Replace IC101.
4
No