Sony CDC-X437 User manual

1
Ver 1.0 2003. 01
Model Name Using Similar Mechanism NEW
CD Drive Mechanism Type MG-930A-185
Optical Pick-up Name OPTIMA-752B2
SERVICE MANUAL
US Model
Canadian Model
CDC-X237/X437
AEP Model
UK Model
CDC-X237
CDC-X237/X437
RADIO SECTION (US, Canadian model)
(FM)
Frequency Range: 87.5 MHz – 108 MHz
Usable Sensitivity: 12.7 dBf
50 dB Quieting Sensitivity: 17.2 dBf
IF Rejection: 100 dB
Frequency Response: 30 Hz – 15,000 Hz
S/N Ratio: 70 dB
Stereo Separation: 35 dB at 1 kHz
Alternate Channel Selectivity: 90 dB
Capture Ratio: 3 dB
(AM)
Frequency Range: 530 kHz – 1,710 kHz
Usable Sensitivity: 30 µV (30 dB)
RADIO SECTION (AEP, UK model)
(FM)
Frequency Range: 87.5 MHz – 108 MHz
Intermediate frequency: 10.7 MHz
Usable Sensitivity: 12.7 dBf
50 dB Quieting Sensitivity: 17.2 dBf
IF Rejection: 100 dB
Frequency Response: 30 Hz – 15,000 Hz
S/N Ratio: 67 dB
Stereo Separation: 35 dB at 1 kHz
Alternate Channel Selectivity: 90 dB
Capture Ratio: 3 dB
(MW)
Frequency Range: 531 kHz – 1,602 kHz
Intermediate frequency: 10.71 MHz/450 kHz
Usable Sensitivity: 30 µV (30 dB)
(LW)
Frequency Range: 144 kHz – 288 kHz (1-kHz/9-kHz steps)
Intermediate frequency: 10.71 MHz/450 kHz
Usable Sensitivity: 30 µV (30 dB)
SPECIFICATIONS
CD SECTION
Frequency Response: 17 Hz – 20 kHz +0/–3 dB
Dynamic Range: More than 85 dB
Channel Separation: More than 60 dB
S/N Ratio: More than 90 dB
Wow/Flutter: Unmeasurable
AUDIO SECTION
Max. Power Output: 45 W ×4 channels
AUX Input
Input sensitivity (load impedance)AUX: 300 mV (10 kΩ)
• The tuner and CD sections have no adjustments.
Sony Corporation
e Vehicle Company
Published by Sony Engineering Corporation
9-877-001-01
2003A0400-1
© 2003. 01
– Continued on next page –
FM/AM COMPACT DISC PLAYER
CDC-X237/X437
FM/MW/LW COMPACT DISC PLAYER
CDC-X237

2
CDC-X237/X437
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous
radiation exposure.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK 0OR DOTTED LINE
WITH MARK 0ON THE SCHEMATIC DIAGRAMS AND IN
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE
PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR
IN SUPPLEMENTS PUBLISHED BY SONY.
ATTENTION AU COMPOSANT AYANT RAPPORT
À LA SÉCURITÉ!!
LES COMPOSANTS IDENTIFIÉS PAR UNE MARQUE 0SUR LES
DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES PIÈCES
SONT CRITIQUES POUR LASÉCURITÉ DE FONCTIONNEMENT.
NE REMPLACER CES COMPOSANTS QUE PAR DES PIÈCES
SONY DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL
OU DANS LES SUPPLÉMENTS PUBLIÉS PAR SONY.
GENERAL
Power-SupplyVoltage: 14.4 V (11 to 16 V allowable),
DC, negative ground
Load Impedance: 4 Ω
Tone Control: Bass ±10 dB at 100 Hz,
Treble ±10 dB at 10 kHz
Preamp Output Voltage (load impedance): 2.2 V (10 kΩ)
Installed size: 182 (W) ×53 (H) ×155 (D) mm
(7 1/4 (W) ×2 1/8 (H) ×6 1/8 (D) inches)
SuppliedAccessory: Carrying case (1)
CARD REMOTE CONTROL (CDC-X437)
Dimensions: approx. 33 (W) ×85 (H) ×7.5 (D) mm
(1 5/16 (W) ×3 3/8 (H) ×5/16 (D) inches)
Weight: approx. 20 g (0.7 oz.) (including battery)
• Specifications and external appearance are subject
to change without notice due to product improvement.
SERVICE NOTES
NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK
OR BASE UNIT
The laser diode in the optical pick-up block may suffer electrostatic
breakdown because of the potential difference generated by the
charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic breakdown and also use
the procedure in the printed matter which is included in the repair
parts.
The flexible board is easily damaged and should be handled with
care.
NOTES ON LASER DIODE EMISSION CHECK
The laser beam on this model is concentrated so as to be focused on
the disc reflective surface by the objective lens in the optical pick-
up block. Therefore, when checking the laser diode emission, ob-
serve from more than 30 cm away from the objective lens.
Notes on Chip Component Replacement
•Never reuse a disconnected chip component.
•Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
•US, Canadian model
•AEP, UK model
CAUTION
Use of controls or adjustments or performance of procedures other
than those specified herein may result in hazardous radiation
exposure.
This compact disc player is classified as a CLASS 1 LASER
product. The CLASS 1 LASER PRODUCT label is located on the
exterior.

3
TABLE OF CONTENTS
1. GENERAL
Connections ............................................................................. 4
2. DISASSEMBLY
2-1. Sub Panel Assy .................................................................... 6
2-2. CD Mechanism Block ......................................................... 6
2-3. Main Board Section ............................................................ 7
2-4. Main Board ......................................................................... 7
2-5. Heat Sink (CT) .................................................................... 8
2-6. Sub Board............................................................................ 8
2-7. Servo Board......................................................................... 9
2-8. Floating Block Assy ............................................................ 9
2-9. Lever Assy (CD Up Holder).............................................. 10
2-10. Lever (CD Roller) Sub Assy ............................................. 10
2-11. Lever Assy (CD Holder) ................................................... 11
2-12. Motor (Sled) Sub Assy ...................................................... 11
2-13. Pick-up Sub Assy .............................................................. 12
3. DIAGRAMS
3-1. IC Pin Descriptions ........................................................... 13
3-2. Block Diagram –CD Section–........................................... 17
3-3. Block Diagram –Main Section–........................................ 18
3-4. Block Diagram –Front Section–........................................ 19
3-5. Circuit Boards Location .................................................... 19
3-6. Printed Wiring Boards –CD Mechanism Section–............ 20
3-7. Schematic Diagram –CD Mechanism Section–................ 22
3-8. Printed Wiring Board –Main Section– .............................. 23
3-9. Schematic Diagram –Main Section (1/2)–........................ 24
3-10. Schematic Diagram –Main Section (2/2)– ........................ 25
3-11. Printed Wiring Boards –Front Section– ............................ 26
3-12. Schematic Diagram –Front Section– ................................ 27
3-13. IC Block Diagrams............................................................ 28
4. EXPLODED VIEWS
4-1. Chassis Section ................................................................. 30
4-2. Front panel Section ........................................................... 31
4-3. CD Mechanism Section (1)............................................... 32
4-4. CD Mechanism Section (2)............................................... 33
5. ELECTRICAL PARTS LIST ........................................ 34
CDC-X237/X437

4
CDC-X237/X437 SECTION 1
GENERAL This section is extracted
from instruction manual.

5
CDC-X237/X437
SECTION 2
DISASSEMBLY
Note : This set can be disassemble according to the following sequence.
2-1. SUB PANEL ASSY
(Page 6)
2-2. CD MECHANISM BLOCK
(Page 6)
2-6. SUB BOARD
(Page 8)
2-7. SERVO BOARD
(Page 9)
SET
2-13. PICK-UP SUB ASSY
(Page 12)
2-4. MAIN BOARD
(Page 7)
2-5. HEAT SINK (CT)
(Page 8)
2-3. MAIN BOARD SECTION
(Page 7)
2-8. FLOATING BLOCK ASSY
(Page 9)
2-9. LEVER ASSY (CD UP HOLDER)
(Page 10)
2-10. LEVER (CD ROLLER) SUB ASSY
(Page 10)
2-11. LEVER ASSY (CD HOLDER)
(Page 11)
2-12. MOTOR (SLED) SUB ASSY
(Page 11)

6
CDC-X237/X437
2-2. CD MECHANISM BLOCK
Note : Follow the disassembly procedure in the numerical order given.
2-1. SUB PANEL ASSY
4 sub panel assy
3 claws
2 claws
1 B 2.6x6
3 CON701
6 CD mechanism block
5 holder (CD mecha
)
1 PTT 2.6x6
2 PTT 2.6x6
4 P 2.6x4

7
CDC-X237/X437
2-4. MAIN BOARD
2-3. MAIN BOARD SECTION
2 cover
3 insulation sheet
4 Removal the solder.
7 MAIN board section
5 Removal the solder.
6 Removal the solder.
1 PTP 2.6x4
0 MAIN board
1 PTT 2.6x6
4 PTT 2.6x6
6 side chassis (L)
8 side chassis (R)
9 front chassis
5 PTT 2.6x6
3 PTT 2.6x6
7 PTT 2.6x6
2 PTT 2.6x
6

8
CDC-X237/X437
2-5. HEAT SINK (CT)
2-6. SUB BOARD
4 heat sink (CT)
1 screw (2.6x8)
2 P 3x12
3 PTT 2.6x
8
3 SUB board
1 Removal the solders.
2 P 1.4x2
black
brown
blue

9
CDC-X237/X437
2-8. FLOATING BLOCK ASSY
2-7. SERVO BOARD
3 PTT 2x3
4 screws (M1.7x4)
5 SERVO board
2 PIC2 FLEXIBLE board
1 Removal the solders.
white
gry
orange
blue
black
red
1 tension spring
2 tension spring
3 tension spring
qd floating block aasy
4 tension spring
5 tension spring
6 claw
7 claw
8 claw
qa oil-damper
qs oil-damper
9
0

10
CDC-X237/X437
2-9. LEVER ASSY (CD UP HOLDER)
2-10. LEVER (CD ROLLER) SUB ASSY
1 P 1.4x2
3 special scre
w
4 tension spring
5 lever assy (CD up holder)
2 leaf spring (roller)
3 lever (CD roller) sub assy
1
2

11
CDC-X237/X437
2-11. LEVER ASSY (CD HOLDER)
2-12. MOTOR (SLED) SUB ASSY
2 special screw
1 torsion spring
4 lever assy (CD holder)
3
1 P 1.7x2
2 motor (sled) sub ass
y

12
CDC-X237/X437
2-13. PICK-UP SUB ASSY
1 B 1.4x5
2 leaf spring
3 pick-up sub ass
y

13
CDC-X237/X437
3-1. IC PIN DESCRIPTIONS
• IC202 LC78622NE (DIGITAL SIGNAL PROCESSOR) (SERVO BOARD)
Pin No. Pin Name I/O Pin Description
1 DEFI I Defect detection signal (DEF) input (Must be connected to 0 V when unused.)
2TAI I Test input pin A pull-down resister is built-in. Must be connected to 0 V.
3PDO O External VCO control phase comparator output
4VVSS — Internal VCO ground pin Must be connected to 0 V.
5ISET — PDO output current adjustment resister connection pin
6VVDD — Internal VCO power supply pin
7FR—VCO frequency range adjustment
8VSS — Digital system ground pin Must be connected to 0 V.
9EFMO O EFM signal output
10 EFMIN I EFM signal input
11 TEST2 I Test input pin A pull-down resister is built-in. Must be connected to 0 V.
12 CLV+ O Disc motor control signal output
13 CLV– O Can be set to three-value output by microprocessor command.
14 V/P O Rough servo/phase control automatic switching monitor output
Outputs a high level during rough servo a low level.
15 HFL I Track detection signal input This is a schmitt input.
16 TES I Tracking error signal input This is a schmitt input.
17 TOFF O Tracking off signal output
18 TGL O Tracking gain switching signal output Increase the gain when low.
19 JP+ O Track jump control signal output
20 JP– O Three-value output is also possible when specified by microprocessor command.
21 PCK O EFM data playback clock monitor signal output
Output pin 4.3218 MHz when the phase is locked. Not used. (Open)
Synchronization signal detection signal output
22 FSEQ O Output a high level when the Synchronization signal detected from the EFM signal
and the internaly generated synchronization signal range. Not used. (Open)
23 VDD — Digital system power supply pin
24 CONT1 I/O General-purpose input/output 1 – 5
25 CONT2 I/O Controlled by serial data commands from the microprocessor.
26 CONT3 I/O Any of these that are unused must be either set up as input pin ports and connected to
27 CONT4 I/O 0 V, or set up as output pin ports and left open.
28 CONT5 I/O Not used. (Open)
De-emphasis monitor signal output
29 EMPH O A high level indicates playback of a de-emphasis disc.
General-purpose input/output pin 6. Not used. (Open)
30 C2F O C2 flag output pin Not used. (Open)
31 DOUT O Digital out signal output (EIJA format) Not used. (Open)
32 TEST3 I Test input pin A pull-down resister is built-in. Must be connected to 0 V.
33 TEST4 I Test input pin A pull-down resister is built-in. Must be connected to 0 V.
General-purpose input/output command identifying pin
A pull-down resister is built-in. Must be connected to 0 V when used with functions
34 PCCL I similar to those of LC78622E.
H: Control possible only for the general-purpose input/output port command.
L: Control possible for all commands.
35 LMUTE O Left channel mute signal output General-purpose input/output pin 7
36 LVDD — Left channel power supply pin
37 LOUT O Left channel output
38 LVSS — Left channel ground pin Must be connected to 0 V.
39 RVSS — Right channel ground pin Must be connected to 0 V.
40 ROUT O Right channel output
41 RVDD — Right channel power supply pin
SECTION 3
DIAGRAMS

14
CDC-X237/X437
Pin No. Pin Name I/O Pin Description
42 RMUTE O Right channel mute signal output General-purpose input/output pin 8
43 XVDD — Crystal oscillator power supply pin
44 XOUT O Connections for a 16.9344 MHz crystal oscillator element pin
45 XIN I
46 XVSS — Crystal oscillator ground pin Must be connected to 0 V.
47 SBSY O Subcode clock synchronization signal output Not used. (Open)
48 EFLG O C1, C2, signal and double error correction monitor pin Not used. (Open)
49 PW O Subcode P, Q, R, S, T, U and W output Not used. (Open)
50 SFSY O Subcode frame synchronization signal output
This signal falls when the subcode are in standby stase. Not used. (Open)
51 SBCK I Subcode readout clock input
This is a schmitt input. (Must be connected to 0 V when unused.)
52 FSX O Output pin for the 7.35 kHz synchronization signal divided from the crystal oscillator
Not used. (Open)
53 WRQ O Subcode Q output standby output
54 RWC I Read/write control signal input This is a schmitt input
55 SQOUT O Subcode Q signal output
56 COIN I Command input pin from system control microprocessor
57 CQCK I Input for both the command input acquisition clock and the SQOUT pin subcode
readout clock input pin This is a schmitt input.
58 RES I Reset signal input This pin must be set low briefly after power is first applied.
59 TST11 O Test output pin Leave open. (Normally output a low level.) Not used. (Open)
60 16M O 16.9344 MHz output pin Not used. (Open)
61 4.2M O 4.2336 MHz output pin
62 TEST5 I Test input pin A pull-down resister is built-in. Must be connected to 0 V.
63 CS I Chip select signal input
A pull-down resister is built-in. Must be connected to 0 V if not controlled.
64 TEST1 I Test input pin No pull-down resister. Must be connected to 0 V.

15
CDC-X237/X437
• IC901 LC72358N-9B50 (SYSTEM CONTROL) (MAIN BOARD)
Pin No. Pin Name I/O Pin Description
1XIN I System clock oscillator input (4.5 MHz)
2TEST2 — Not used. (Open)
3CD DATA IN — Not used. (Open)
4NC—Not used. (Open)
5NC—Not used.
6E-VOL DO O Date output for volume level control
7LCD DI I LCD driver date signal input
8LCD DO O LCD driver date signal output
9LCD CLO O LCD driver clock signal output
10 LCD CE O LCD driver CE signal output
11 SQ OUT I Sub-code Q input terminal
12 COIN O Command output terminal for DSP
13 CQCK O Transfer-out clock for command output or output terminal for sub-code transfer
clock from SQ OUT
14 SD/ST I Stereo signal input when receiving “H”=MONO, “L”=ST FM reception.
Channel detection signal input when FM/AM seeking “H”=detect channel.
15 LOC/DX O LOC/DX switching output when in the radio seek mode “H”=LOC, “L”=DX.
16 IF REQ O IF count signal request output
17 NC — FM/AM power switch output “H”=AM, “L”=FM Not used. (Open)
18 TU ON O Radio power switch output “H”=Radio mode Not used. (Open)
19 NC — Not used. (Open)
20 E-VOL CE O CE output for volume level control
21 ACC CONT — Not used. (Open)
22, 23 KS4, KS3 O Initial setting diode matrix output Not used. (Open)
24 – 26 KS2 – KS0 O Initial setting diode matrix output
27, 28 K3, K2 I Initial setting diode matrix input
29 K1 I Initial setting diode matrix input CD test mode, pulled down when not used.
30 K0 I Initial setting diode matrix input
31 VDD — Power supply pin
32 E-VOL CLO O Clock output for volume level control
33 LM SW O Loading or SLED GAIN switch output
34 NC — Not used. (Open)
35 FEM+ LM+ O Sled motor control terminal
36 FEM– LM– O Sled motor control terminal
37 RW O RW disc control output Normal set to “H”.
38 LP UP O RW disc control output Normal set to “L”.
39 CD ON O CD power switch output
40 A-MUTE O Audio mute signal output
41 POWER CONT O Power control signal output
42 ST-BY MUTE O ST-BY mute signal output
43 POWER MUTE O Power mute signal output
44 BEEP O BEEP output (3 kHz, 50 ms)
45 DFP IN I Front panel detection signal input
46 DRF I “Detect RF” RF level detection input Pulled up when not used.
47 WRQ I Sub-code Q output standby input terminal
48 RWC O Read/write control output terminal
49 CD RES O DSP reset output terminal
50 OPEN — Not used. (Open)
51 SW2 I 12 cm disc detection/12 cm disc ejection and detection
52 SW1 I Leading motor start detection
53 R-ENCOD2 I Rotary encoder input 2
54 R-ENCOD1 I Rotary encoder input 1

16
CDC-X237/X437
Pin No. Pin Name I/O Pin Description
55 LCD-DI I LCD driver date signal input
56 REMOTE IN I Remote controller input, pulled up when not used, only CDC-X437 US model.
57 LED O Not used. (Open)
58 FM O FM/AM power switch output “H”=AM, “L”=FM
59 AM O FM/AM power switch output “L”=AM, “H”=FM
60 NC — Not used. (Open)
61 ACC DET I ACC (accessory power) ON/OFF LEVEL input OFF=fault mode.
62 CD INSIDE I Pick up inner track position detection (LMT SW)
63 TEST I CD test mode Pulled down when not used.
64 L IND I Voltage input for level indicater Pulled down when not used.
65 PH. MUTE I External mute control, “L”=–20 dB mute, pulled up when not used. (EUR)
66 RESET I System reset signal input “L”=system reset
67 ACC IN I ACC (accessory power) ON/OFF input OFF=fault mode.
68 SNS I Backup detection signal input
69 BATT IN I Input battery ON/OFF
70 IF (FM/AM) I IF count signal input (FM/AM)
71 EO3 — Not used. (Open)
72 SUB PD — Not used. (Open)
73 VDD — Power supply pin
74 AM OSC I AM channel transmission input
75 FM OSC I FM channel transmission input
76 VSS — Connected to GND
77 EO2 — Not used. (Open)
78 EO1 O Error out from change pump (for FM/AM)
79 TEST1 — Not used. (Open)
80 XOUT O System clock oscillator output (4.5 MHz)

17 17
CDC-X237/X437
3-2. BLOCK DIAGRAM — CD SECTION —
(Page 18)
54 53 52 56 54
58
15 2928 26 2716
51
50
49
44
43
42
41
40
39
38
37
36
35
34
33
32
57
61
1
9
53
55
44
45
40
37
10
12
13
14
15
16
17
18
19
20
62
63
2
3
4
1
31
30
FOCUS
COIL
DRIVE
CD-DA/CD-RW
SWITCHING
Q202-205
LASER
DRIVE
Q206
LD
DRIVE
Q201
TRACKING
COIL
DRIVE
SPINDLE
MOTOR
DRIVE
5V
REG.
8
9
20
M2
(SPINDLE) M
M1
(SLED/LOADING) M
-
+
+
-
5V
FOCUS
COIL
TRACKING
COIL
VIN3
VIN3G
VIN4
VIN4G
VIN2
VIN2G
VIN1
REG IN
VIN1G
MUTE
VO3+
VO3-
VO4+
VO4-
VO2+
VO2-
VO1+
VO1-
REG
OUT
FOCUS/TRACKING COIL DRIVE,
SLED/SPINDLE/LOADING MOTOR DRIVE,
IC203
6
7
4
5
13
15
25
16
14
19
REG
DRIVE
Q207
24
23
17
18 S3
(RESET)
S2
(DETECT2)
S1
(DETECT1)
+5V
VC
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
DRF
CE
DAT
COIN
RWC
FIN2
CQCK
4.2M
EFMO
DEFI
EFMIN
CLV+
CLV-
V/P
HFL
TES
TOFF
TGL
JP+
JP-
F
E
FIN1
LDS
LDD
FD TO SLEQ SP- SPD SLD
RES
CL
WRQ
SQOUT
XIN
XOUT
ROUT
LOUT
CLK
DEF
SLI
SLC
RFS-
RFSM
CV+
CV-
SLOF
HFL
TES
TOFF
TGL
JP+
JP-
SL+
SL-
10
11
X201
16.934MHz
SERVO CONTROL,
DIGITAL SIGNAL PROCESSOR
IC202
RF AMP,ANALOG SERVO,
ANALOG SIGNAL PROCESSOR
IC201
RW
LP UP
CQCK
DRF
RWC
COIN
WRQ
SQOUT
CD R
CD L
SW1
SW2
INSIDE
CD RES
LM SW
8V(CD)
FEM+
FEM-
OPTICAL PICK-UP
BLOCK
MAIN
SECTION
A
SLED/
LOADING
MOTOR
DRIVE
SLED/
LOADIMG
SWITCH
Q208
• Signal path
:CD

1818
CDC-X237/X437
3-3. BLOCK DIAGRAM — MAIN SECTION —
(Page 17)
(Page 19)
116
AMANT
J101
(ANTENNA)
2FMANT TUN-RCH
LCH
17
RCH
22
SD/ST
TU101
(TUNER UNIT)
AUX-RCH
15
64
12
13
SYSTEM CONTROL
IC901
ELECTRONIC VOLUME
IC401
LROUT
20
EVOL CE
EVOL CLD
6
32
EVOL DO
40
A MUTE
43
POWER MUTE
LSELO
LIN
L IND
75 FMOSC
74 AMOSC
78 EO1
16 IF REQ
70 IF(FM/AM)
14 ST/SD
LOC/DX
XIN
RESET
4ST-BY
22 MUTE
RL
FL
11
POWER AMP
IC501
2
CNP801
R-CH
FL+
10
FL-
RL+
RL-
3
11
RR+
RR-
4
12
FR+
FR-
+B
7ACC
+B
R-CH
BATT
PON+B
F901
6ANT-R
17
19
18
16 BATT
42
STBY MUTE
44
BEEP
65
P.H MUTE
61
ACC DET
39
CD ON
66
16 AUX IN
LJ401
R
AUX(L)
TUN(L)
17 CD(L)
9
7
12
1
9
5
3
MUTE
Q402
AUDIO OUT
REAR
MUTE
Q401
4
LFOUT
DI
CE
CL
5
1
2
36
15
11
AM/FM OSC
6
FMVT
14
AMVT
20
IF REQ/OUT
3
AM DX/LOC
4
FM DX/LOC
14
X901
4.5kHz
S901
(RESET)
1
CD INSIDE
62
LM SW
33
SW1
52
SW2
51
FEM+LM+
35
FEM-LM-
36
CD RES
49
RW
37
RWC
48
WRQ
47
SQOUT
11
DRF
46
COIN
12
CQCK
13
LP UP
CD INSIDE
LM SW
8V(CD)
CD R
CD+8V
CD-RCH
CD L
SW1
SW2
FEM+
FEM-
CD RES
RW
RWC
WRQ
SQOUT
DRF
COIN
CQCK
LP UP 38
80 XOUT
55
LCD DI
8
LCD DO
10
LCD CE
41
POWER CONT
45
DFP IN
7
LCD DI
54
R ENCOD1
9
LCD CLO
53
R ENCOD2
56
REMOTE IN
LCD DO
LCD CE
DFP IN
LCD DI
RE 1
LCD CLO
RE 2
REMOTE
69 1
BATT IN 2 IN
CD+8V
OUT BATT
BATT
COM+9V
SW+8V REG
Q831-833
BATT DET
IC941
COM+9V
LAMP+B
PON+B
BATT
SW+14V REG
Q801
POWER CONTROL
SWITCHING
Q802
COM+9V REG
Q821
BU+5V BATT
+5V REG
Q811
LEVEL AMP
Q451
VOL/
TONE FADER
LPF(AM)
Q101,102
FM+B
FM+B
SWITCHING
Q106
COM+9V
AM+B
AM+B
SWITCHING
Q105
LOCAL
SWITCHING
Q109
BATT
SHUTDOWN
MUTE
Q591,592
MUTE
CONTROL
Q441,442
13 TEL MUTE
RL(+)
RL(-)
FL(+)
FL(-)
J601
AUX
R906 CDC-X237:AEP,UK MODEL,
CDC-X437
FRONT
SECTION
B
CD
SECTION A
58
FM
59
AM
• Signal path
: CD
: FM
: AM
: AUX
• R-ch is omitted due to same as L-ch.

19 19
CDC-X237/X437
3-4. BLOCK DIAGRAM — FRONT SECTION —
(Page 18)
61
62
63
64
LCD DRIVER
IC601
1
S1
LCD601
LIQUID
CRYSTAL
DISPLAY
5
I
35
•
41
I
43
44
I
49
50
I
52
S5
I
S35
KS1
I
KS6
KI1
I
KI3
COM1
I
COM3
2
S2
3
S3
REMOTE
RE1
RE2
LCD DI
LCD CLO
LCD CE
LCD DO
DFP IN
LAMP+B
D641-643D651-653
671-673
D661
LCD
BACK LIGHT
DIMMER
CONTROL
Q661
REMOTE
CONTROL
RECEIVER
IC681
S621
ROTARY
ENCODER
WITH
SWITCH
KEY
MATRIX
ILL
CONTROL
Q651,671
S601,602,605,606
608,610-619
DI
CL
CE
DO
CDC-X437
MAIN
SECTION
B
3-5. CIRCUIT BOARDS LOCATION
KEY board
SUB board SERVO board
MAIN board
AUX board
tuner uni
t
(TU101)
— Main Board —
1
4.5MHz
IC901 1(XIN)
1.8Vp-p
• Waveforms
— Servo Board —
(MODE: CD PLAY)
1
IC201 ra (RFSM)
0.9Vp-p
2
3
Approx. 600mVp-p
IC201 7(TE)
0V
4.4Vp-p
4.2336MHz
IC201 t; (CLK)
4
1.2Vp-p
16.9344MHz
IC202 rg (XIN)

2020
CDC-X237/X437
3-6. PRINTED WIRING BOARDS — CD MECHANISM SECTION — • Refer to page 19 for Circuit Boards Location.
Note:
The components identi-
fied by mark 0or dotted
linewith mark 0are criti-
cal for safety.
Replace only with part
number specified.
Note:
Lescomposants identifiés par
une marque 0sont critiques
pour la sécurité.
Ne les remplacer que par une
piéce portant le numéro
spécifié.
THIS NOTE IS COMMON FOR PRINTED WIRING
BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is
printed in each block.)
for schematic diagram:
•All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.
•All resistors are in Ωand 1/4W or less unless otherwise
specified.
•%: indicates tolerance.
•f: internal component.
•C: panel designation.
•A: B+ Line.
•Powervoltage is dc 14.4Vand fedwith regulateddc power
supply from ACC and BATT cords.
•Voltagesare taken witha VOM(Inputimpedance10 MΩ).
Voltage variations may be noted due to normal produc-
tion tolerances.
•Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
•Circled numbers refer to waveforms.
•Signal path.
F: FM
f: AM/MW/LW
J: CD
for printed wiring boards:
•X: parts extracted from the component side.
•Y: parts extracted from the conductor side.
•x: parts mounted on the conductor side.
•a: Through hole.
•: Pattern from the side which enables seeing.
(The other layer’s patterns are not indicated.)
Caution:
Pattern face side: Partsonthe patternface sideseenfromthe
(Side B) pattern face are indicated.
Parts face side: Parts on the parts face side seen from the
(Side A) parts face are indicated.
1
A
B
C
D
E
F
G
H
I
J
2345678910111213
X201
C223
C233
Q207
C226
C268
C222
C227 C264
C236
C263
C202
C237
C201
C211
C251
C280
C267
C224
C281
C206
C231
C229