VSX-LX70
31
5
6
7
8
5
6
7
8
C
D
F
A
B
E
5. DIAGNOSIS
5.1 DIAGNOSIS FLOWCHART
5.1.1 DSP TROUBLESHOOTING
•
It
is
assumed
that
there
is
no
loose
connection
or
damage
in
the
LCRs.
•
Refer
to
"
DSP
Block
Diagram
"
and
"
DSP
Assy
check
point
"
as
the
parts
marked
to
in
the
troubleshooting
are
located.
Unsophisticated
Diagnosis
DSP
Ass
'
y
malfunction
is
detected
(The
part
can
be
roughly
expected
j
ust
by
operation
of
the
main
unit.)
•
Has
DSP
Ass
'
y
caused
the
malfunction
?
Inputing
a
PCM
(such
as
CD)
digital
signal,
check
if
the
sound
plays
by
switching
AUTO
SURR
/
STREAM
DIRECT.
When
the
sound
doesn
'
t
play
in
AUTO
SURROUND
or
DIRECT
MODE
though
it
does
in
PURE
DIRECT
(PCM
DIRECT)
MODE,
DSP
Ass
'
y
might
be
defective.
Step
2:
Power
supply
Step
1:
Connections
CN401,
CN402
Are
the
connectors
securely
inserted
?
Insert
the
connectors
securely.
No
CN402
(Pins
24-26)
IC511
(Pin
5)
Is
the
voltage
5V
?
No
5V
input
1st,
2nd
Block
3.3V
No
Replace
CN402.
Check
the
output
from
the
DIGITAL
MOTHER
Assy.
Yes
Replace
IC511.
Yes
Is
there
any
loose
connection
at
Pins
24-26
of
CN402
?
Is
the
voltage
3.3V
?
No
No
The
output
and
GND
may
be
short-
circuited.
Check
the
path
between
them.
Yes
Yes
Is
IC511
abnormally
hot
?
A
Yes
To
Step
2
A
A
AF
B
IC101
(Pin
B3,
etc.) 1st
DSP
3.3V
Is
the
voltage
3.3V
?
No
Yes
C
Check
the
parts
and
patterns
in
the
path.
Check
the
parts
and
patterns
in
the
path.
IC161
(Pin
20)
LATCH
1
Is
the
voltage
3.3V
?
No
Yes
D
Check
the
parts
and
patterns
in
the
path.
IC162
(Pin
20)
LATCH
2
Is
the
voltage
3.3V
?
No
Yes
E
Check
the
parts
and
patterns
in
the
path.
IC163
(Pin
8)
Decoder
Is
the
voltage
3.3V
?
No
Yes
Check
the
parts
and
patterns
in
the
path.
IC164
(Pins
12,
37) FLASH
ROM
Is
the
voltage
3.3V
?
No
Yes
F
Check
the
parts
and
patterns
in
the
path.
IC171
(Pins
9,
27)
SRAM
Is
the
voltage
3.3V
?
No
Yes
Troubleshooting
