Sony CDXC-4750 Service manual

CDX-C4750/C6600

SERVICE MANUAL

Ver 1.1 2001. 02

Photo: CDX-C4750

SPECIFICATIONS

AUDIO POWER SPECIFICATIONS (US Model)

POWER OUTPUT AND TOTAL HARMONIC DISTORTION
17 watts per channel minimum continuous average power into
4 ohms, 4 channels driven from 20 Hz to 20 kHz with no more
than 1% total harmonic distortion.

US Model

CDX-C4750

E Model

CDX-C6600

Model Name Using Similar Mechanism CDX-C480/C580
CD Drive Mechanism Type MG-363X-121
Optical Pick-up Name KSS-521A

Other Specifications
CD player section

System Compact disc digital audio

Signal-to-noise ratio 90 dB
Frequency response 10 – 20,000 Hz
Wow and flutter Below measurable limit
Laser Diode Properties

Material GaAlAs
Wavelength 780 nm
Emission Duration Continuous
Laser output power Less than 44.6 µW*

* This output is the value measured at a distance

of 200 mm from the objective lens surface on the
Optical Pick-up Block.

Tuner section

FM

Tuning range US model:

Antenna terminal External antenna connector
Intermediate frequency 10.7 MHz
Usable sensitivity 12 dBf
Selectivity 75 dB at 400 kHz
Signal-to-noise ratio 65 dB (stereo),

Harmonic distortion at 1 kHz

Separation 35 dB at 1 kHz
Frequency response 30 – 15,000 Hz

system

87.5 – 107.9 MHz
E model:
FM tuning interval:
50 kHz/200 kHz switchable

87.5 – 108.0 MHz
(at 50 kHz step)

87.5 – 107.9 MHz
(at 200 kHz step)

68 dB (mono)

0.7% (stereo),

0.5% (mono)

AM

Tuning range US model:

Antenna terminal External antenna connector
Intermediate frequency 10.7 MHz/450 kHz
Sensitivity 30 µV

Power amplifier section

Outputs Speaker outputs

Speaker impedance 4 – 8 ohms
Maximum power output 40 W × 4 (at 4 ohms)

530 – 1,710 kHz
E model:
AM tuning interval:
9 kHz/10 kHz switchable
531 – 1,602 kHz
(at 9 kHz step)
530 – 1,710 kHz
(at 10 kHz step)

(sure seal connectors)

– Continued on next page –

FM/AM COMPACT DISC PLAYER

9-926-441-12

2001B0400-1
© 2001. 2

Sony Corporation

Audio Entertainment Group
General Engineering Dept.

– 1 –

General

Outputs Line outputs (2)

Power antenna relay
control lead
Power amplifier control
lead
Telephone ATT control
lead

Tone controls Bass ±8 dB at 100 Hz

Treble ±8 dB at 10 kHz

Power requirements 12 V DC car battery

(negative ground)

Dimensions Approx. 178 × 50 × 185 mm

(7 1/8 × 2 × 7 3/8 in.)
(w/h/d)

Mounting dimensions Approx. 182 × 53 × 162 mm

(7 1/4 × 2 1/8 × 6 1/2 in.)

(w/h/d)
Mass Approx. 1.2 kg (2 lb. 10 oz.)
Supplied accessories Parts for installation and

connections (1 set)

Front panel case (1)

Design and specifications are subject to change without
notice.

SERVICE NOTE

CAUTION

Use of controls or adjustments or performance of proce­dures other than those specified herein may result in haz­ardous radiation exposure.

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.

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, observe
from more than 30 cm away from the objective lens.

TABLE OF CONTENTS

1. GENERAL

Location of controls ................................................................ 3

Getting Started ........................................................................ 3

Setting the clock ..................................................................... 3

CD Player................................................................................ 3

Radio ....................................................................................... 4

Other Functions ...................................................................... 4

CD/MD Unit ........................................................................... 5

TV/Video ................................................................................ 7

Connections ............................................................................8

2. DISASSEMBLY

2-1. Cover Assy ........................................................................ 10

2-2. Front Panel Assy ............................................................... 10

2-3. Sub Panel (1) Assy ............................................................ 11

2-4. CD Mechanism Block ....................................................... 11

2-5. Main Board .......................................................................12

2-6. Heat Sink........................................................................... 12

2-7. Chassis (T) Sub Assy ........................................................ 13

2-8. Lever Assy.........................................................................13

2-9. Servo Board.......................................................................14

2-10. Roller Assy ........................................................................ 14

2-11. Chassis (OP) (O/S) Assy ...................................................15

2-12. Optical Pick-up Block ....................................................... 15

3. ELECTRICAL ADJUSTMENTS

Tuner Section ........................................................................ 16

CD Section ............................................................................ 18

4. DIAGRAMS

4-1. Block Diagram –CD Section–...........................................19

4-2. Block Diagram –Main Section–........................................ 21

4-3. Circuit Boards Location .................................................... 23

4-4. Printed Wiring Boards –CD Mechanism Section– ........... 25

4-5. Schematic Diagram –CD Mechanism Section–................ 27

4-6. Printed Wiring Board –Main Section–..............................29

4-7. Schematic Diagram –Main Section (1/2)–........................ 33

4-8. Schematic Diagram –Main Section (2/2)–........................ 35

4-9. Printed Wiring Board –Display Section–..........................37

4-10. Schematic Diagram –Display Section–............................. 39

4-11. IC Pin Description............................................................. 45

5. EXPLODED VIEWS

5-1. Chassis Section .................................................................48

5-2. Front Panel Section ........................................................... 49

5-3. CD Mechanism Section (1)............................................... 50

5-4. CD Mechanism Section (2)............................................... 51

5-5. CD Mechanism Section (3)............................................... 52

NOTES ON PICK-UP FLEXIBLE BOARD

The pick-up flexible board in this set is secured to the optical pick-up
with an adhesive tape. Once the tape is removed , an adhering force
becomes weak, and it cannot be reused.
Therefore, if the optical pick-up is replaced, replace also the pick-up
flexible board with a new one.

SAFETY-RELATED COMPONENT WARNING!!

COMPONENTS IDENTIFIED BY MARK ! OR DOTTED LINE
WITH MARK ! ON THE SCHEMATIC DIAGRAMS AND IN
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PAR TS WHOSE
P ART NUMBERS APPEAR AS SHOWN IN THIS MANU AL OR
IN SUPPLEMENTS PUBLISHED BY SONY.

6. ELECTRICAL PARTS LIST......................................... 53

– 2 –

SECTION 1

GENERAL

This section is extracted from
CDX-C4750’s instruction manual.

– 3 –

– 4 –

– 5 –

– 6 –

– 7 –

– 8 –

– 9 –

SECTION 2

DISASSEMBLY

Note : Follow the disassembly procedure in the n umerical order given.

2-1. COVER ASSY

1

claw

3

claws

4

cover assy

2

claw

2-2. FRONT PANEL ASSY

1

button (release)

2

front panel assy

– 10 –

2-3. SUB PANEL (1) ASSY

5

1

PTT 2.6x6

sub panel (1) assy

3

claw

4

claw

2

PTT 2.6x6

2-4. CD MECHANISM BLOCK

8

5

CD mechanism block

2

PTT 2.6x6

bracket (M/D)

7

PTT 2.6x6

3

PTT 2.6x6

6

PTT 2.6x6

1

PTT 2.6x6

– 11 –

4

CNP700

2-5. MAIN BOARD

3

ground point screws

(PTT 2.6x6)

4

MAIN board

2

ground point screw

(PTT 2.6x6)

1

PTT 2.6x8

2-6. HEAT SINK

1

PTT 2.6x8

4

heat sink

2

PTT 2.6x12

3

PTT 2.6x8

– 12 –

2-7. CHASSIS (T) SUB ASSY

1

Unsolder the

lead wires.

red

white

black

4

P 2x3

2

P 2x3

3

P 2x3

5

chassis (T) sub assy

2-8. LEVER ASSY

6

lever (R) assy

3

tension spring (LR)

7

lever (L) assy

5

guide (disc)

1

PS 2x4

2

DISC IN SW board

4

claws

– 13 –

2-9. SERVO BOARD

5

3

P 2x3

4

loading motor assy

PS 2x4

1

CN3

6

PS 2x4

2

CN2

7

SERVO board

2-10. ROLLER ASSY

4

PS 2x3

5

LOAD SW board

washer

arm

washer

3

2

Fig. 1

roller assy

arm (roller)

washers

arm

1

tension spring (RA)

– 14 –

2-11. CHASSIS (OP) (O/S) ASSY

8

compression spring (FL)

1

tension spring (KF1)

7

9

compression spring (FL)

2

tension spring (KR1)

5

Fit lever (D) in the

direction of the arrow.

chassis (OP) (O/S) assy

6

Turn loading ring in the

direction of the arrow.

4

damper (T)

2-12. OPTICAL PICK-UP BLOCK

1

P 2x3

2

sled motor assy

3

damper (T)

3

optical pick-up block

– 15 –

SECTION 3

r

)

ELECTRICAL ADJUSTMENTS

TUNER SECTION 0 dB = 1 µV

Cautions during repair

When the tuner unit is defective, replace it by a new one because
its internal block is difficult to repair.

FM Center Adjustment

Setting:

SOURCE button : FMI
D-BASS switch : OFF
Frequency Select switch (E model) : FM 200K

FM RF signal

generator

Carrier frequency: 97.9 MHz
Output lever : 60 dB (1 mV)
Mode : mono
Modulation : 1 kHz, 75 kHz de viation (100%)

FM CENTER

OUT

(Both side

of R24.)

Procedure:

1. Adjust IFT4 on TU601 so that the reading on the digital

voltmeter becomes in 0 ± 30 mV.

2. Output an Fcenter 10 dB signal output from FM RF signal

generator so that the speaker out is –20 dBs.

3. Change the FM RF signal generator frequency and check the

deviation of the frequency on + side and – side when the speaker
out drops 3 dB. (Both + side and – side is approx. 50 kHz.)

4. Re-adjust IFT4 on TU601 when the difference deviation of the

frequency does more than 10 kHz.

0 dBs

IC1 pin
IC1 pin

dummy

antenna

50

50

Ω

#¶

#¢

Ω

antenna
terminal

set

digital
voltmete

+
–

FM SENS/IF Adjustment

Setting:

SOURCE button : FMI
D-BASS switch : OFF
Frequency Select switch (E model) : FM 200K

FM RF signal

generator

dummy

antenna

50

50

Ω

antenna
terminal

Ω

Procedure:

Adjust for a maximum reading on level meter.

FEB1

87.5 MHz

Adjustment Location: See page 17.

AM SENS Adjustment

Setting:

SOURCE n MODE button : AM
D-BASS switch : OFF
Frequency Select switch (E model) : AM 10K

AM RF signal

generator

dummy

antenna

30

Ω

30 pF

antenna

terminal

15 pF

Procedure:

Adjust for a maximum reading on level meter.

IFT1, 3

1,400 kHz

set

SPEAKER OUT

set

SPEAKER OUT

level
meter

4

Ω

+
–

level
meter

4

Ω

+

–

–3 dBs

(fc–10)

fc

Adjustment Location: See page 17.

(fc+10)

Adjustment Location: See page 17.

(kHz

– 16 –

AM Auto Scan/Stop Level Adjustment

Setting:

SOURCE n MODE button : AM
D-BASS switch : OFF
Frequency Select switch (E model) : AM 10K

AM RF signal

generator

dummy

antenna

30

Ω

15 pF

30 pF

antenna
terminal

set

digital
voltmeter

S-METER OUT

level
meter

4

Ω

+

–

Procedure:

1. Adjust IFT3 on TU601 so that the reading on the digital

voltmeter is 1.5 ± 0.2 V.

+
–

Carrier frequency: 1000 kHz
30% amplitude
modulation by
1 kHz signal
output level : 33 dB (44.7 µV)

Adjustment Location: tuner assy (TU601)

– tuner assy (TU601) (component side) –

AM AUTO

SCAN/STOP

LEVEL ADJ

IFT3

SPEAKER OUT

AM SENS

ADJ

IFT3 IFT1

Adjustment Location: tuner assy (TU601)

IFT4

FM CENTER

ADJ

– tuner assy (TU601) (conductor side) –

IC1

S-METER

FEB1

FM SENS/IF

ADJ

R24

OUT

‘

’

FM CENTER
OUT

– 17 –

CD SECTION

Note:

1. CD Block basically constructed to operate without adjustment.

Therefore, check each item in order given.

2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.

3. Use the oscilloscope with more than 10 MΩ impedance.

4. Clean an objective lens by an applicator with neutral detergent

when the signal level is low than specif ied v alue with the following
checks.

Focus Bias Adjustment

Setting: This adjustment is performed with the set placed

horizontally.

oscilloscope

SERVO board

TP (RF)

TP (RF. GND)

Procedure:

1. Connect an oscilloscope between TP (RF) and TP (RF. GND)

on the SERVO board.

2. Connect the power supply.

3. Push the RESET button (S900) on the MAIN board.

4. Insert the disc (YEDS-18) and playback.

5. Adjust RV1 so that the oscilloscope waveform is clear and check

RF signal level is correct or not.

Note: Clear RF signal waveform means that the sharp “≈” can be

clearly distinguished at the center of the waveform.

+
–

Focus Gain Adjustment (Coarse adjustment)

This adjustment is not required unless the following parts are re placed:

• Optical pick-up

•RV4

Procedure:

1. Set RV4 to the standard position. (mechanical center)

2. Check whether operation noise (while noise type) caused by
the 2-axis device (lens section of the optical pick-up) is
abnormally loud.
If the operation noise is too loud, turn RV4 slightly counter­clockwise.

• If the gain is too low:
Focus does not function and no music is selected.

• If the gain is too high:
Noise caused by scratches and dust is heard and the operation
becomes unstable.

Adjustment Location: servo board

Adjustment Location: servo board (component side)

FOCUS GAIN ADJ

IC3

CN2

RV4

RF signal waveform

VOLT/DIV: 200 mV
TIME/DIV: 500 nS

level: 1.0 – 1.5 Vp-p

• When observing the eye pattern, set the oscilloscope to AC range
and raise the vertical sensitivity so that it may be easily seen.

Adjustment Location: servo board

CN1

IC1

TP

(RF. GND)

IC2

TP

(RF)

CN3

RV1

FOCUS BIAS ADJ

– 18 –