Pioneer SX-LX70SW Service Manual page 39

5
Check the following points when the source is
J
Multi ch.
IC751 (Pin 12)
Is there
No
abnormality at the
a audio data
parts and patterns
(with Cch source)?
in the path?
Yes
IC751 (Pin 28) LSSD
Is there
No
abnormality at the
a audio data
parts and patterns
(with Sch source)?
in the path?
Yes
IC3101 (Pin 30)
Is there
No
abnormality at the
a audio data
parts and patterns
(with Sch source)?
in the path?
Yes
LSCD
IC751 (Pin 27)
Is there
No
abnormality at the
a audio data
parts and patterns
(with Cch source)?
in the path?
Yes
I3101 (Pin 29)
Is there
No
abnormality at the
a audio data
parts and patterns
(with Cch source)?
in the path?
Yes
to CIRCUIT DESCRIPTION OF DIGITAL
AMP. SECTION
5
6
Is there
No
Replace IC701
or IC751.
Is there
No
Replace IC751
or IC3101.
Is there
No
Replace IC751
or IC3101.
Is there
No
Replace IC751
or IC3101.
Is there
No
Replace IC751
or IC3101.
SX-LX70SW
6
7
Step 8: 1st DSP
IC101 B10 (R104) DSP1RST(20D) (DSP UCOM)
No
Check the parts and patterns
Is the voltage
in the path.
3.3 V?
Yes
Is the
voltage of DSP1RST
It is likely a Boot Error.
No
maintained in 3.3V?
(It is very difficult to diagnose which
(Does it fall to become
peripheral part of the DSP is in failure.)
0V periodically?)
IC101 F2 (R109) IRQ1 (89D) (DSP UCOM)
Does the
voltage become
No
The 1st DSP or the communication
3.3 V for a moment
path is in failure.
when the input stream
is changed?
Yes
IC101 A11 (R136) DSP1CS (90D) (DSP UCOM)
Does the
voltage become
No
Check the parts and patterns
0 V for a moment
in the path.
when the input stream
is changed?
Yes
For the following diagnosis, a digital
oscilloscope must be used.
IC101 B9 (R103)
DSP CCLK (100D) (DSP UCOM)
Is the clock
No
Check the parts and patterns
signal output while the
in the path.
voltage is 0 V?
Yes
IC101 A9 (R132)
DSP CDOUT (99D) (DSP UCOM)
Is the clock
No
Check the parts and patterns
signal output while the
in the path.
voltage is 0 V?
Yes
K
7
8
A
B
C
D
E
F
39
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