Service manual

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