35
SC-LX81
5
6
7
8
5
6
7
8
A
B
C
D
E
F
Step 7: 1st DSP
It is likely a boot error.
(It is very difficult to diagnose
which peripheral part of the
DSP is in failure.)
DSP1SS0
RESET
DSP1SS1
Is the logic of
DSP1XRST "H"
?
Replace IC2701.
No
No
Yes
Yes
Does the logic
become "L" for a moment
when the input stream
is changed?
Does the logic
become "L" for a moment
when the input stream
is changed?
Yes
IC2701 (Pin 112)
IC2701 (Pin 115)
IC2701 (Pin 114)
IC2701 (Pin 113)
IC2701 (Pin 111)
IC2701 (Pin 117)
Check the output of Pin30 of
IC2201 (DSP uCOM) on the path.
Check the output of Pin126 of
IC2201 (DSP uCOM) on the path.
Check the output of Pin128 of
IC2201 (DSP uCOM) on the path.
Check the output of Pin5 of
IC2201 (DSP uCOM) on the path.
Check the output of Pin32 of
IC2201 (DSP uCOM) on the path.
Check the output of Pin28 of
IC2201 (DSP uCOM) on the path.
Check the output of Pin5 of
IC2201 (DSP uCOM) on the path.
Check the output of Pin4 of
IC2201 (DSP uCOM) on the path.
No
Yes
No
Yes
No
DSPSCK
Yes
No
DSPMOSI
Yes
No
DSPMISO
AT
It is very difficult to diagnose
which part is in failure.
For the following diagnosis,
a digital oscilloscope must
be used.
For the following diagnosis,
a digital oscilloscope must
be used.
AO
AP
AQ
AR
AS
Step 8: 2nd DSP
The 2nd DSP or the commu-
nication path is in failure.
Is the logic
of DSP2XRST "H"
?
IC2801 (Pin 47)
No
Yes
AU
IC2801 (Pin 37)
AV
No
Yes
No
Does the logic
of DSP2XRST periodically
become "H" or
"L"?
IC2801 (Pin 36)
AW
Yes
Check the output of Pin4 of
IC2201 (DSP uCOM) on the path.
No
IC2801 (Pin 34)
AX
Yes
Yes
No
Yes
No
IC2801 (Pin 35)
DSPMISO
RESET
DSP2SS
DSPSCK
DSPMOSI
AY
It is very difficult to diagnose
which part is in failure.
The 2nd DSP is in failure.
Replace it.
Does clock
signal output have
DSP1SS0 and DSP1SS1
for a period of "L"?
Does clock
signal output have
DSP1SS0 and DSP1SS1
for a period of "L"?
Does clock
signal output have
DSP1SS0 and DSP1SS1
for a period of "L"?
Is the logic
of DSP2XRST maintained
at "H"? (Does it fall to become
"L" periodically?)
Does clock signal
output have DSP2SS
for a period of "L"?
Does clock signal
output have DSP2SS
for a period of "L"?
Does clock signal
output have DSP2SS
for a period of "L"?
Is the logic
of RST_1 maintained
at "H"? (Does it fall to become
"L" periodically?)