Pioneer VSX-1018AH-K Service Manual page 60

1
A
Step 5: Digital audio output switching
IC801
output Pin
-
33,36
USB
playback
31
34
18
B
26
iPod
playback
27
28
IC801 (Pins 18,26,27,28)
15
No
Is there
each output?
C
Yes
IC801 (Pins 31,33,34)
16
No
Is there
each output?
Yes
17
IC503 (Pin 12)
OSCU (24.576 MHz : when USB reproduces)
D
Is there
No
output of
24.576 MHz
?
Yes
18
IC851 (Pin 1)
UASW (USB Audio Switch)
When USB reproduces
No
: High and
when iPod
reproduces : Low?
E
Yes
For the output of IC851, each digital audio
signal should be output at each reproduction.
To diagnosis
flow of DSP
F
60
1
2
With this product, the digital audio signal output route from IC801 (USB host) varies
depending the USB reproduction and iPod reproduction.
It is controlled and switched by USAW (USB Audio Switch) using the IC851 (logic IC).
Signal
name
OSCU Master clock (24.576MHz) from IC503 of DSP block is used.
MSCK Mass Strage Clock.
MSDA Mass Strage Data.
MSSS Mass Strage SS.
IMCK iPod Master Clock.
ISDAT iPod Serial Data.
IBCK iPod Bit Clock.
ILRCK iPod LR Clock.
IMCK, ISDAT, IBCK, ILRCK (when iPod reproduces)
Check each audio output terminal of IC801.
MSDA, MSCK, MSSS (when USB reproduces)
Check each audio output terminal of IC801.
Check the peripheral circuit of IC503.
Check the UASW (Pin 2) of CN701 (CN702).
Check the pattern between CN701 (CN702) and IC851.
Check the MAIN ASSY.
2
3
Meaning and details
VSX-LX51
3
4
4