CDX-A250, CDX-A250EE - Sony Car Audio Service Manual (repair manual)

1

Model Name Using Similar Mechanism

CDX-GT300/GT300EE/GT300S/

GT350/GT350S

CD Drive Mechanism Type

MG-611WA-186//Q

Optical Pick-up Name

KSS1000E

AEP Model

UK Model

E Model

Chinese Model

CDX-A250

East European Model

CDX-A250EE

• The tuner and CD sections have no adjustments.

2006J04-1

© 2006.10

Signal-to-noise ratio:

120 dB

Frequency response:

10 – 20,000 Hz

Wow and flutter:

Below measurable limit

FM
Tuning range:

CDX-A250 (AEP, UK, EA):
87.5 – 108.0 MHz
CDX-A250 (E, CH, IND):
87.5 – 108.0 MHz (at 50 kHz step)
87.5 – 107.9 MHz (at 200 kHz step)
CDX-A250EE:
FM1/FM2: 87.5 – 108.0 MHz
(at 50 kHz step)
FM3: 65 – 74 MHz
(at 30 kHz step)

FM tuning interval (CDX-A250 (E, CH, IND) only):

50 kHz/200 kHz switchable

Antenna terminal:

External antenna connector

Intermediate frequency:

10.7 MHz/450 kHz

Usable sensitivity:

9 dBf

Selectivity:

75 dB at 400 kHz

Signal-to-noise ratio:

67 dB (stereo), 69 dB (mono)

Harmonic distortion at 1 kHz:

0.5 % (stereo), 0.3 % (mono)

Separation:

35 dB at 1 kHz

Frequency response:

30 – 15,000 Hz

AM (CDX-A250 (E, EA, CH, IND)/A250EE)
Tuning range:

CDX-A250 (E, CH, IND):
531 – 1,602 kHz (at 9 kHz step)
530 – 1,710 kHz (at 10 kHz step)
CDX-A250EE, CDX-A250 (EA):
531 – 1,602 kHz

AM tuning interval (CDX-A250 (E) only):

9 kHz/10 kHz switchable

Antenna terminal:

External antenna connector

Intermediate frequency:

10.7 MHz/450 kHz

Sensitivity:

30 

µV

MW/LW (CDX-A250 (AEP, UK))
Tuning range:

MW: 531 – 1,602 kHz
LW: 153 – 279 kHz

Aerial terminal:

External aerial connector

Intermediate frequency:

10.7 MHz/450 kHz

Sensitivity:

MW: 30 

µV, LW: 40 µV

– Continued on next page –

(Photo: CDX-A250)

2

If the optical pick-up block is defective, please replace the whole
optical pick-up block.
Never turn the semi-fixed resistor located at the side of optical
pick-up block.

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.

This label is located on the bottom of the chassis.

CH model

TEST DISCS
Please use the following test discs for the check on the voltage and
the waveforms of the CD section.

YDES-18 (Part No. 3-702-101-01)
PATD-012 (Part No. 4-225-203-01)

optical pick-up

semi-fixed resistor

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.

EXCEPT CH model

COMPONENTS  IDENTIFIED  BY  MARK  0  OR  DOTTED  LINE
WITH  MARK  0  ON  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.

Outputs:

Speaker outputs (sure seal connectors)

Speaker impedance:

4 – 8 ohms

Maximum power output: CDX-A250 (E, EA, CH, IND):

52 W 

× 4 (at 4 ohms)

CDX-A250 (AEP, UK)/A250EE:
50 W 

× 4 (at 4 ohms)

Outputs:

Audio outputs terminal (sub/rear switchable)
Power antenna relay control terminal
Power amplifier control terminal

Inputs:

Antenna input terminal
AUX input jack (stereo mini jack)

Tone controls:

Low: 

±10 dB at 60 Hz (XPLOD)

Mid: 

±10 dB at 1 kHz (XPLOD)

High: 

±10 dB at 10 kHz (XPLOD)

Power requirements:

12 V DC car battery (negative ground)

Dimensions:

Approx. 178 

× 50 × 178 mm

(w/h/d)

Mounting dimensions:

Approx. 182 

× 53 × 162 mm

(w/h/d)

Mass:

Approx. 1.2 kg

Supplied accessories:

Parts for installation and connections (1 set)
Card remote commander: RM-X151

• Abbreviation

EA : Saudi Arabia model
CH : Chinese model
IND : Indian model

3

z

Boards requiring use of unleaded solder are printed with the lead
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with
the lead free mark due to their particular size.)

Unleaded solder has the following characteristics.
• Unleaded solder melts at a temperature about 40°C higher than

ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
about 350°C.
Caution: The printed pattern (copper foil) may peel away if the
heated tip is applied for too long, so be careful!

• Strong viscosity

Unleaded solder is more viscous (sticky, less prone to flow)
than ordinary solder so use caution not to let solder bridges
occur such as on IC pins, etc.

• Usable with ordinary solder

It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.

SERVO BOARD
CN2

MAIN BOARD
CNP301

J-2502-076-1

When repairing or servicing this set, connect the jig (extension cable)
as shown below.

• Connect the MAIN board (CNP301) and the SERVO board (CN2)

with the extension cable (Part No. J-2502-076-1).

You can play CD-DA (also containing CD TEXT*), CD-R/CD-
RW (MP3/WMA files also containing Multi Session and ATRAC
CD (ATRAC3 and ATRAC3plus format).

Type of discs

Label on the disc

CD-DA

MP3

WMA

ATRAC CD

* A CD TEXT disc is a CD-DA that includes information such as

disc, artist and track name.

4

Location of controls and basic operations ............................... 5
Connections ............................................................................. 7

2-1. Sub Panel Assy .................................................................. 10
2-2. CD Mechanism Block ....................................................... 10
2-3. Main Board ....................................................................... 11
2-4. Chassis (T) Sub Assy ........................................................ 11
2-5. Roller Arm Assy ................................................................ 12
2-6. Chassis (OP) Assy ............................................................. 12
2-7. Optical Pick-up ................................................................. 13
2-8. SL Motor Assy (M902) ..................................................... 13
2-9. LE Motor Assy (M903) ..................................................... 14
2-10. Servo Board ....................................................................... 14

3-1. Block Diagram – CD Section – ......................................... 15
3-2. Block Diagram – Main Section – ...................................... 16
3-3. Block Diagram – Display Section – .................................. 17
3-4. Circuit Boards Location .................................................... 17
3-5. Printed Wiring Boards – CD Mechanism Section – ......... 19
3-6. Schematic Diagram – CD Mechanism Section (1/2) – ..... 20
3-7. Schematic Diagram – CD Mechanism Section (2/2) – ..... 21
3-8. Printed Wiring Board – Main Section – ............................ 22
3-9. Schematic Diagram – Main Section (1/3) – ...................... 23
3-10. Schematic Diagram – Main Section (2/3) – ...................... 24
3-11. Schematic Diagram – Main Section (3/3) – ...................... 25
3-12. Printed Wiring Boards – Key Section – ............................ 26
3-13. Schematic Diagram – Key Section – ................................ 27

4-1. Main Section ..................................................................... 34
4-2. Front Panel Section ........................................................... 35
4-3. CD Mechanism Section (1) (MG-611WA-186//Q) ........... 36
4-4. CD Mechanism Section (2) (MG-611WA-186//Q) ........... 37
4-5. CD Mechanism Section (3) (MG-611WA-186//Q) ........... 38
4-6. CD Mechanism Section (4) (MG-611WA-186//Q) ........... 39

........................................ 40