Sony CX-LMN75 / XR-MN75 Service Manual ▷ View online
25
CX-LMN75
RFDC signal waveform
Checking Location: CD board (Conductor side)
CD SECTION
Note:
1. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
2. Use an oscilloscope with more than 10M
2. Use an oscilloscope with more than 10M
Ω impedance.
3. Clean the object lens by an applicator with neutral detergent when the
signal level is low than specified value with the following checks.
RFDC Le
Note:
Note:
Note:
vel Check
Connection:
Procedure:
1.
1.
Connect an oscilloscope to test point (RFDCO) and TP (VC)
on the BD board.
on the BD board.
2.
Turn the power on.
3.
Put the disc (YEDS-18) in to playback the number five track.
4.
Confirm that oscilloscope waveform is clear and check RFDC
signal level is correct or not.
signal level is correct or not.
A clear RFDC signal waveform means that the shape “
◊” can be
clearly distinguished at the center of the waveform.
+
–
–
BD board
TP (RFDCO)
TP (VC)
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
TIME/DIV: 500 ns
level: 0.6
±
0.15 Vp-p
RFAC Level Check
Connection:
Procedure:
1.
1.
Connect an oscilloscope to test point TP (RFACO) and TP
(VC) on the BD board.
(VC) on the BD board.
2.
Turn the power on.
3.
Put the disc (YEDS-18) in to playback the number five track.
4.
Confirm that oscilloscope waveform is clear and check RFAC
signal level is correct or not.
signal level is correct or not.
A clear RFAC signal waveform means that the shape “
◊” can be
clearly distinguished at the center of the waveform.
RFAC signal waveform
Checking Location: BD board (Side B)
+
–
–
BD board
TP (RFACO)
TP (VC)
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
TIME/DIV: 500 ns
level: 1.0
±
0.4 Vp-p
S-curve Check
Connection:
Procedure:
1.
1.
Connect an oscilloscope to test point TP (FEO) and TP (VC)
on the BD board.
on the BD board.
2.
While depressing the CD button, insert an AC plug.
3.
Put the disc (YEDS-18) in and press the button and
actuate the focus search. (actuate the focus search when
disc table is moving in and out)
actuate the focus search. (actuate the focus search when
disc table is moving in and out)
4.
Check the oscilloscope waveform (S-curve) is symmetrical
between A and B. And confirm peak to peak level within 2
between A and B. And confirm peak to peak level within 2
± 1
Vp-p.
S-curve waveform
• Try to measure several times to make sure than the ratio of A : B
or B : A is more than 10 : 7.
• Take sweep time as long as possible and light up the
brightness to obtain best waveform.
Checking Location: BD board (Side B)
+
–
–
BD board
TP (FEO)
TP (VC)
oscilloscope
A
B
symmetry
within 2
±
1 Vp-p
u
x
26
CX-LMN75
Checking Location: BD board (Side B)
+
–
–
BD board
TP (TEO)
TP (VC)
oscilloscope
Traverse Waveform
0V
B
level: 1.0
±
0.5 Vp-p
Center of
the waveform
the waveform
A (DC
voltage)
Traverse Waveform
0V
Tracking servo
Sled servo
ON
C (DC
voltage)
voltage)
Tracking servo
Sled servo
OFF
6.
Press the CD
u
button. (The tracking servo and sledding
servo are turned ON)
Rotate RV101 on BD board and adjust the C (DC voltage)
is almost equal to the A (DC voltage) in step 4.
Rotate RV101 on BD board and adjust the C (DC voltage)
is almost equal to the A (DC voltage) in step 4.
7. To exit from this mode, turn the power off.
Notes:
• Always move the optical pick-up to most inside track when
exiting from this mode. Otherwise, a disc will not be unloaded.
• Do not run the sled motor excessively, otherwise the gear can
be chipped.
E-F Balance Adjustment
Connection:
Procedure:
1.
1.
Connect an oscilloscpe to test point TP (TEO) and TP (VC) on
the BD board.
the BD board.
2.
AC is put in pushing CD
u
button to enter the CD test
mode.
3.
Put the disc (YEDS-18) in to playback the number five track.
4.
Press the CD button. If it plays, press the CD
u
(CD) button. (The tracking servo and the
button again. (The tracking servo and the sledding servo are
turned OFF)
turned OFF)
5.
Check the level B of the oscilliscope's waveform and the A
(DC voltage) of the center of the Traverse waveform.
Confirm the following :
A/B x 100 = less than
(DC voltage) of the center of the Traverse waveform.
Confirm the following :
A/B x 100 = less than
±
10%
Checking Location:
– BD BOARD (Side B) –
u
(CONDUCTOR SIDE)
BD BOARD
IC251
IC301
IC101
IC303
TP
(RFACO)
TP
(VC)
TP
(FEO)
TP
(RFDCO)
TP
(VEO)
27
27
CX-LMN75
CX-LMN75
SECTION 8
DIAGRAMS
• Waveforms
– BD Board –
– BD Board –
1.2Vp-p
1
IC101
ra
(RFACO)
200mV/DIV, 1
µ
s
/DIV
2
IC101
uj
(XTAO)
1V/DIV, 40ns/DIV
3.3Vp-p
59.1ns (16.9MHz)
3
IC901
qd
(16MHz-OUT)
1V/DIV, 40ns/DIV
1.9Vp-p
62.7ns
(16MHz)
4
IC901
qa
(32kHz-OUT)
1V/DIV, 20
µ
s
/DIV
1.9Vp-p
30.5
µ
s
(32.768kHz)
– MAIN Board –
• Circuit Boards Location
THIS NOTE IS COMMON FOR PRINTED WIRING
BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed
in each block.)
BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed
in each block.)
For schematic diagrams.
Note:
• All capacitors are in
• All capacitors are in
µ
F unless otherwise noted. pF:
µµ
F
50 WV or less are not indicated except for electrolytics
and tantalums.
and tantalums.
• All resistors are in
Ω
and
1
/
4
W or less unless otherwise
specified.
∗
: Impossible to measure
•
f
: internal component.
•
2
: nonflammable resistor.
•
1
: fusible resistor.
•
C
: panel designation.
For printed wiring boards.
Note:
• X
: parts extracted from the component side.
• Y
: parts extracted from the conductor side.
•
f
: internal component.
•
: Pattern from the side which enables seeing.
•
A
: B+ Line.
•
B
: B– Line.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : Power on
no mark : Power on
• Voltages are taken with a VOM (Input impedance 10 M
Ω
).
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Circled numbers refer to waveforms.
• Signal path.
F
: TUNER
J
: CD
d
: AUX
E
: PB (TAPE)
a
: REC (TAPE)
• Abbreviation
SP
: Singapore model
E51
: Chilean and Peruvian model
KR
: Korea model
AUS
: Australian model
• Indication of transistor
B
These are omitted.
C
E
Q
C
B
These are omitted.
E
Q
Caution:
Pattern face side:
Pattern face side:
Parts on the pattern face side seen from
(Conductor Side)
the pattern face are indicated.
Parts face side:
Parts on the parts face side seen from
(Component Side) the parts face are indicated.
B
These are omitted.
C
E
Q
MODE MOTOR board
ROLLER MOTOR board
STOCKER MOTOR board
SW (1) board
CONNECTOR board
ST ENCODER board
PT board
MAIN board
FRONT board
HOLDER board
HP board
BD board
SW (2) board
SW (3) board
SW (4) board
SENSOR board
Note: The components identified by mark
0
or dotted line
with mark
0
are critical for safety.
Replace only with part number specified.
Ver. 1.2
28
28
CX-LMN75
CX-LMN75
8-1. BLOCK DIAGRAM — BD/CHANGER SECTION —
MIACK
8
PO11/BUCK/AD14
36
MILP
5
RESET
2
MICS
4
MIDIO
6
MICK
7
MP3 DECODER
IC301
A/D
CONVERTER
CH2OUTF
CH2OUTR
23
24
21
4
5
6
7
17
18
16
15
RFACI
ASYO
ASYI
FILTER
FILO
PCO
CLTV
FILI
DIGITAL PLL
ASYMMETRY
CORRECTOR
EFM
DEMODULATOR
CD DSP
IC101 (1/2)
MDP
DIGITAL
CLV
PROCESSOR
32K
RAM
ERROR
CORRECTOR
INTERNAL BUS
SQCK
SQSO
EXCK
AOUT1
C4M
XTSL
XTAO
XTAI
AOUT2
R-CH
D/A
DIGITAL
INTERFACE
D/A
CONVERTER
SELECTOR
CLOCK
GENERATOR
SUBCODE
PROCESSOR
SCOR
WFCK
XUGF
GFS
EMPH
SENS
DATA
CLOCK
XLAT
SBSO
O-SENS
I-DATA
I-XLT
TEI
FEI
FOCUS/
TRACKING/SLED
SERVO DSP
FOCUS/TRACKING/SLED
PWM GENERATOR
SFDR
CH3FIN
CH4IN
CH3RIN
CH3OUTF
CH3OUTR
CH1FIN
CH1RIN
CH2FIN
CH2RIN
20
MUTE
SRDR
TFDR
TRDR
FFDR
FRDR
SSTP
COUT
MIRR,
DFCT, FOK
DETECTOR
SERVO AUTO
SEQUENCER
SERVO
INTERFACE
CPU INTERFACE
SCLK
TO CPU INTERFACE
FOK
MIRR
DFCT
2
OPIN+
CH4OUTF
CH4OUTR
27
OPOUT
M101
(SPINDLE)
MOTOR
DRIVE
MOTOR
DRIVE
COIL
DRIVE
CH1OUTF
CH1OUTR
COIL
DRIVE
M
M
M102
(SLED)
MOTOR/COIL DRIVE
IC251
2-AXIS
DEVICE
(TRACKING)
(FOCUS)
CD DSP
IC101 (2/2)
• Signal Path
: CD PLAY
14
13
11
12
O-SCOR
A
MAIN
SECTION
CD
13
11
12
9
10
14
119
108
21 23
3
1
2
7
TO SERVO AUTO
SEQUENCER
42
51 53
XPCK
112
50 52
45
46
6
XRST
100
O-X-RST
60
96 97
81
78
117
93
77
86
98 99
115
107
102 105 104
110 111 113 68
35
I-CLK
37 36
LRCK
BCK
PCMD
LRCKIA
SDI0
63 66 65
16
BCKIA
15
SFSY/LRCKIB
19
SBSY/BCKIB
18
14
LRCKI
BCKI
PCMDI
SDO0
62 60 61
11
56 19
26
27
28
29
24
22
20
19
37
36
E
B
A
D +3.3V
F
DETECTOR
A
B
C
D
RF
SUMMING
AMP
FOCUS
ERROR
AMP
TRACKING
ERROR AMP
RFACO
FEO
TEO
E
F
AUTOMATIC
POWER
CONTROL
Q10
APC LD
AMP
LD
LD
PD
LASER DIODE
OPTICAL PICK-UP
BLOCK
(KSM-215CFP)
PD
I-V AMP
D
C
EQ_
IN
41
35
34
EQ
AC_
SUM
RFAC
VCA
X171
16.9344MHz
SYSTEM CONTROLLER
IC901 (1/2)
S101
(LIMIT)
I-MP3DAT 6
O-MP3DAT 5
O-MP3CLK 7
I-MI-CS 47
I-MP3-ACK 32
I-MP3-REQ 33
O-MILT 48
MP3-RST 45
I-XTACN 57
STANDBY
3
I-MP3-STBY 49
• R-ch is omitted due to same as L-ch
XTACN
95
71
O-LOD_NEG
O-LOD_POS
O-SLD_POS
O-SLD_NEG
72
I-D. SENSOR
I-SW5-B
I-SW5-A
I-SW4
I-SW3
I-SW2-A
I-SW2-B
I-SW1-A
70
O-ELV_POS
O-ELV_NEG
69
84
85
67
OUT1
FIN
OUT2
RIN
IC721 STOCKER MOTOR DRIVE
M761
(STOCKER)
M
7
9
4
2
82
83
OUT1
FIN
OUT2
RIN
IC711 ROLLER MOTOR DRIVE
M781
(ROLLER)
M
7
9
4
2
73
81
OUT1
FIN
OUT2
RIN
IC701 MODE MOTOR DRIVE
S771 ROTARY ENCODER (MODE)
M771
(MODE)
M
7
9
4
2
S713 (DISC IN (8/12cm))
S714 (DISC IN (8cm))
S715 (DISC OUT)
S716 (STOCKER IN/OUT)
S711 (DISC INSERT(8/12cm))
S717 (DISC POSITION)
S718 (STOCKING)
1
G
2
3
4
61
86
59
63
I-ELV_3
I-ELV_2
I-ELV_1
I-ELV_0
I-SLD_3
I-SLD_2
I-SLD_1
I-SLD_0
S702 ROTARY ENCODER (STOCKER POSITION)
1
2
3
4
79
75
76
77
68
80
78
(ON : When disc insert)
S711
S713
S714
S715
S717
S718
(ON : When disc out from play position)
In the midst disc is moving
between play position and stocker
ON : disc is play position side
OFF : disc is stocker side
between play position and stocker
ON : disc is play position side
OFF : disc is stocker side
OFF: In the Midst disc is moving
between play position and
stocker
stocker
(ON : Play position)
(8cm disc only)
ON : Play position
S716
from stocker
ON : The moment disc in/out
LEVEL
SHIFT
Q731
DISC INSERT
DETECT SENSOR
IC751
G
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