CDX-GT490U, CDX-GT490US, CDX-GT494U, CDX-GT49UM — Sony Car Audio Service Manual (repair manual)

Model
CDX-GT490U CDX-GT490US CDX-GT494U CDX-GT49UM
Pages
40
Size
2.27 MB
Type
PDF
Document
Service Manual
Brand
Device
Car Audio
File
cdx-gt490u-cdx-gt490us-cdx-gt494u-cdx-gt49um.pdf
Date

View Sony CDX-GT490U / CDX-GT490US / CDX-GT494U / CDX-GT49UM Service Manual online

SERVICE MANUAL
Sony Corporation
Audio&Video Business Group
Published by Sony Techno Create Corporation
CDX-GT49UM/GT490U/
GT490US/GT494U
FM/AM COMPACT DISC PLAYER
9-889-625-02
2009K04-1
© 
2009.11
E Model
CDX-GT490U/GT490US
Indian Model
CDX-GT49UM/GT494U
Ver. 1.1  2009.11
SPECIFICATIONS
Tuner section
FM
Tuning range: 
  Except Saudi Arabia model:
  87.5 – 108.0 MHz (at 50 kHz step)
  87.5 – 107.9 MHz (at 200 kHz step)
 Saudi 
Arabia 
model:
  87.5 – 108.0 MHz
FM tuning interval: 
  Except Saudi Arabia model:
  50 kHz/200 kHz switchable
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
AM 
Tuning range:
  Except Saudi Arabia model:
  531 – 1,602 kHz (at 9 kHz step)
  530 – 1,710 kHz (at 10 kHz step)
 Saudi 
Arabia 
model:
  531 – 1,602 kHz 
AM tuning interval: 
  Except Saudi Arabia model:
  9 kHz/10 kHz switchable
Antenna (aerial) terminal:
  External antenna (aerial) connector
Intermediate frequency: 25 kHz
Sensitivity: 26 
μV
CD player section
Signal-to-noise ratio:
 120 dB
Frequency response: 10 – 20,000 Hz
Wow and fl utter: Below measurable limit
USB Player section
Interface:
 USB (Full-speed)
Maximum current: 500 mA
Power amplifi er section
Outputs:
 Speaker outputs (sure seal connectors)
Speaker impedance: 4 – 8 ohms
Maximum power output: 52 W 
× 4 (at 4 ohms)
General
Outputs:
  Audio outputs terminal 
  (front, 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)
  USB signal input terminal
Model Name Using Similar Mechanism
CDX-GT33U
CD Drive Mechanism Type
MG-101Y-188//Q
Optical Pick-up Name
DAX-25A
•  The tuner and CD sections have no adjustments.
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 accessories:
  Card remote commander: RM-X151
  Parts for installation and connections (1 set)
Design and specifi cations are subject to change
without notice.
Photo: CDX-GT490US
CDX-GT49UM/GT490U/GT490US/GT494U
2
NOTES  ON  CHIP  COMPONENT  REPLACEMENT
 •  Never reuse a disconnected chip component.
 •  Notice that the minus side of a tantalum capacitor may be 
damaged by heat.
TEST DISCS
Please use the following test discs for the check on the CD 
section.
 
YDES-18 (Part No. 3-702-101-01)
 
PATD-012 (Part No. 4-225-203-01)
SAFETY-RELATED  COMPONET  WARNING!
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.
NOTES  ON  HANDLING  THE OPTICAL  PICK-UP 
 
BLOCK  OR  BASE  UNIT
The laser diode in the optical pick-up block may suffer electrostat-
ic 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.
optical pick-up
semi-fixed resistor
CDX-GT49UM/GT490U/GT490US/GT494U
3
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)
 : LEAD  FREE  MARK
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.
This label is located on the bottom of the chassis.
1. 
SERVICE  NOTE
 ......................................................  
4
2. GENERAL
 Connections 
....................................................................  
5
3. DISASSEMBLY
3-1.   Sub Panel Assy  ...............................................................   9
3-2.   CD Mechanism Block .....................................................   9
3-3.   Main Board .....................................................................   10
3-4. Servo 
Board 
....................................................................  10
3-5.  Chassis (T) Sub Assy ......................................................   11
3-6. Roller 
Arm 
Assy 
..............................................................  11
3-7. Chassis 
(OP) 
Assy 
...........................................................  12
3-8. Chucking 
Arm 
Sub 
Assy 
.................................................  12
3-9. Sled 
Motor 
Assy 
..............................................................  13
3-10.  Optical Pick-up Section ..................................................   14
3-11. Optical Pick-up ...............................................................   14
4. DIAGRAMS
4-1.  Block Diagram –Main Section– .....................................   15
4-2.  Block Diagram –Display Section– .................................   16
4-3.  Printed Wiring Board –Main Section– ............................   18
4-4.  Schematic Diagram –Main Section (1/3)– ......................   19
4-5.  Schematic Diagram –Main Section (2/3)– ......................   20
4-6.  Schematic Diagram –Main Section (3/3)– ......................   21
4-7.  Printed Wiring Boards –Key Section– ............................   22
4-8.  Schematic Diagram –Key Section– ................................   23
5. EXPLODED 
VIEWS
5-1. Main 
Section 
...................................................................  29
5-2.  Front Panel Section .........................................................   30
5-3.  CD Mechanism Section (MG-101Y-188//Q) ..................   31
6. 
ELECTRICAL PARTS LIST
 ..................................   32
TABLE  OF  CONTENTS
CDX-GT49UM/GT490U/GT490US/GT494U
4
SECTION  1
SERVICE  NOTE
EXTENSION  CABLE  AND  SERVICE  POSITION
When repairing or servicing this set, connect the jig (extension 
cable) as shown below.
•  Connect the MAIN board (CN701) and the SERVO board 
(CN401) with the extension cable (Part No. J-2502-076-1).
NOTE  FOR  REPLACEMENT  OF  THE  SERVO  BOARD
When repairing, the complete SERVO board (Part No. 
A-1555-002-A) should be replaced since any parts in the SERVO 
board cannot be repaired.
NOTE FOR REPLACEMENT OF THE USB CONNECTOR 
(CN902)
To replace the USB connector requires alignment.
1.  Insert the USB connector into the front panel.
2.  Place the KEY board on the front panel and align the terminals 
of the USB connector with the holes in the KEY board.
3.  Solder the four terminals of the connector.
NOTE  FOR  THE  20-PIN  CONNECTOR (CN901)
Do not use alcohol to clean the 20-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.
SERVO BOARD
CN401
MAIN BOARD
CN701
J-2502-076-1
KEY board
USB (socket) connector
front panel
Page of 40

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Here you can view online or download Sony CDX-GT490U / CDX-GT490US / CDX-GT494U / CDX-GT49UM Service Manual in pdf. This Service Manual can help you recover, restore, fix, disassemble and repair Sony CDX-GT490U / CDX-GT490US / CDX-GT494U / CDX-GT49UM Car Audio. Information contained in Sony CDX-GT490U / CDX-GT490US / CDX-GT494U / CDX-GT49UM service manual (repair manual) typically includes:

  • Disassembly, troubleshooting, programming, maintenance, remote, adjustment, installation and setup instructions.
  • Schematics, wiring and block diagrams.
  • Printed wiring boards (PWB) and printed circuit boards (PCB).
  • Parts list (bill of materials).