CDX-GT25, CDX-GT29, CDX-GT29EE - Sony Car Audio Service Manual (repair manual)

2009L04-1

© 

2009.12

•  The tuner and CD sections have no adjustments.

Model Name Using Similar Mechanism

CDX-GT230/GT232

CD Drive Mechanism Type

MG-101L-188//Q

Optical Pick-up Name

DAX-25A

Photo: CDX-GT25

CD Player section
Signal-to-noise ratio: 120 dB
Frequency response: 10 – 20,000 Hz
Wow and fl utter: Below measurable limit

Tuner section
FM
Tuning range:
  GT25/GT29: 87.5 – 108.0 MHz
 GT29EE:
     FM1/FM2: 87.5 – 108.0 MHz (at 50 kHz)
     FM3: 65 – 74 MHz (at 30 kHz)
Antenna (aerial) terminal:
  External antenna (aerial) connector
Intermediate frequency: 150 kHz
Usable sensitivity: 10 dBf
Selectivity: 75 dB at 400 kHz
Signal-to-noise ratio: 70 dB (mono)
Separation: 40 dB at 1 kHz
Frequency response: 20 – 15,000 Hz

MW/LW
Tuning range:
  MW: 531 – 1,602 kHz
  LW: 153 – 279 kHz
Antenna (aerial) terminal:
  External antenna (aerial) connector
Intermediate frequency: 25 kHz
Sensitivity: MW: 26 

μV, LW: 45 μV

Power amplifi er section
Output: Speaker outputs (sure seal connectors)
Speaker impedance: 4 – 8 ohms
Maximum power output: 45 W 

× 4 (at 4 ohms)

General
Outputs:
  Audio outputs terminal (sub/rear switchable)
  Power antenna (aerial) relay control terminal
 Power 

amplifi er control terminal

Inputs:
  Remote controller input terminal
  Antenna (aerial) 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 (earth))
Dimensions: Approx. 178 

× 50 × 179 mm

 (7

 1/8

 

× 2 × 7

 1/8

 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 11 oz)
Supplied accessory:
  Parts for installation and connections (1 set)

Design and specifi cations are subject to change
without notice.

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.

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 

The laser diode in the optical pick-up block may suffer electro-
static break-down because of the potential difference generated by 
the charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic break-down and also 
use the procedure in the printed matter which is included in the 
repair parts.
The fl exible 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 refl ective surface by the objective lens in the optical 
pickup block. Therefore, when checking the laser diode emission, 
observe from more than 30 cm away from the objective lens.

CAUTION
Use of controls or adjustments or performance of procedures 
other than those specifi ed herein may result in hazardous radia-
tion exposure.

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

TEST  DISCS
Please use the following test discs for the check on the CD section.

 

YEDS-18 (Part No. 3-702-101-01)

 

PATD-012 (Part No. 4-225-203-01)

This compact disc player is classifi ed as a CLASS 1 LASER 
product. The CLASS 1 LASER PRODUCT label is located on the 
exterior.

This label is located on the bottom of the chassis.

  .............................................   4

  

Connections ....................................................................   5

3-1.   Sub Panel Assy ................................................................   7
3-2.   CD Mechanism Block .....................................................   7
3-3.   Main Board .....................................................................   8
3-4. Servo 

Board 

....................................................................   8

3-5.  Chassis (T) Sub Assy ......................................................   9
3-6. Roller 

Arm 

Assy 

..............................................................   9

3-7. Chassis 

(OP) 

Assy 

...........................................................  10

3-8. Chucking 

Arm 

Sub 

Assy 

.................................................  10

3-9. Sled 

Motor 

Assy 

..............................................................  11

3-10.  Optical Pick-up Section ..................................................   12
3-11. Optical Pick-up ...............................................................  12

4-1.  Block Diagram –Main Section– .....................................   13
4-2.  Block Diagram –Display Section– .................................   14
4-3.  Printed Wiring Board –Main Section– ............................   15
4-4.  Schematic Diagram –Main Section (1/3)– ......................   16
4-5.  Schematic Diagram –Main Section (2/3)– ......................   17
4-6.  Schematic Diagram –Main Section (3/3)– ......................   18
4-7.  Printed Wiring Board –Key Section– .............................   19
4-8.  Schematic Diagram –Key Section – ...............................   20

5-1. Main 

Section 

...................................................................  26

5-2.  Front Panel Section .........................................................   27
5-3.  CD Mechanism Section (MG-101L-188//Q) ..................   28

  ..............................   29

UNLEADED  SOLDER
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 fl ow) 
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.

EXTENSION  CABLE  AND  SERVICE  POSITION
When repairing or servicing this set, connect the jig (extension 
cable) as shown below.

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

(CN401) with the extension cable (Part No. J-2502-076-1).

NOTE  FOR  REPLACEMENT  OF  THE  AUX  JACK (J901)
To replace the AUX jack requires alignment.
1.  Insert the AUX jack into the KEY board.
2.  Place the KEY board on the front panel. 
3.  Solder the three terminals of the jack.

NOTE  FOR  REPLACEMENT  OF  THE  SERVO  BOARD
When repairing, the complete SERVO board (Part No. A-1552-
122-A) should be replaced since any parts in the SERVO board 
cannot be repaired.

NOTE  FOR  THE  15-PIN  CONNECTOR (CN901)
Do not use alcohol to clean the 15-pin connector (CN901) connect-
ing the front panel with the main body.
Do not touch the connector directly with your bare hand. Poor con-
tact may be caused.

KEY board

AUX jack

front panel