Pioneer VSX-94TXH Service Manual page 35

5
QQ Step 7: 1st DSP
3 7 63 1515 0
f
CN401 (Pin 20)
Is the logic
of RST_1 "H"
?
Yes
w
R139
Is the logic
of RST_1 "H"
?
Yes
Is the logic
of RST_1 maintained
at "H"? (Does it fall to become
"L" periodically?)
Yes
g
R134
Does the logic
become "H" for a moment
when the input stream
is changed?
Yes
TE g
L 13942296513
CN401 (Pin 21)
Does the logic
become "H" for a moment
when the input stream
is changed?
Yes
h
CN401 (Pin 17)
Does the logic
become "L" for a moment
when the input stream
is changed?
Yes
x
R137
Does the logic
become "L" for a moment
when the input stream
is changed?
Yes
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RESET
No
Check the output from the
DIGITAL MOTHER Assy.
No
Check the resistors and patterns
in the path.
It is likely a boot error.
No
(It is very difficult to diagnose
which peripheral part of the
DSP is in failure.)
REQ_1
No
The 1st DSP is in failure.
Replace it.
No
Check the resistors and patterns
in the path.
SPIDS_1
No
Check the output from the
DIGITAL MOTHER Assy.
No
Check the resistors and patterns
in the path.
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y
i
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2 9
8
j
CN401 (Pin 16)
Is the clock
signal output while the
voltage at SPIDS_1
is "L"?
Yes
y
R144
Is the clock
signal output while the
voltage at SPIDS_1
is "L"?
Yes
k
CN401 (Pin 19)
Is the clock
signal output while the
voltage at SPIDS_1
is "L"?
Yes
z
R146
Is the clock
Q Q
signal output while the
3 6 7 1 3 1 5
voltage at SPIDS_1
is "L"?
Yes
AA
R142
Is the clock
signal output while the
voltage at SPIDS_1
is "L"?
Yes
i
CN401 (Pin 18)
Is the clock
signal output while the
voltage at SPIDS_1
is "L"?
Yes
It is very difficult to diagnose
which part is in failure.
co
.
VSX-94TXH
7
8
9 4 2 8
For the following diagnosis, a digital
oscilloscope must be used.
SPICLK
No
Check the output from the
DIGITAL MOTHER Assy.
No
Check the resistors and patterns
in the path.
MOSI
No
Check the output from the
DIGITAL MOTHER Assy.
No
Check the resistors and patterns
0 5 8 2 9 9 4 2 8
in the path.
MISO
No
The 1st DSP is in failure.
Replace it.
No
Check the resistors and patterns
in the path.
m
9 9
A
B
C
9 9
D
E
F
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