JVC KD-G489UR Service Manual

SERVICE MANUAL

CD RECEIVER

MA34020076SERVICE MANUAL

KD-G489UR

* Please refer to the mechanism manual (model TN2007-1010 (No.MY005, No.MY005B))

Lead free solder used in the board (material : Sn-Ag-Cu, melting point : 219 Centigrade) Lead free solder used in the board (material : Sn-Cu, melting point : 230 Centigrade)

TABLE OF CONTENTS

1 PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10

5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11

No.MA340

2007/6

SPECIFICATION

AUDIO AMPLIFIER SECTION

Power Output 20 W RMS × 4 Channels at 4 Ω and [< or =] 1% THD+N

Ω

Signal-to-Noise Ratio 80 dBA (reference: 1 W into 4

Ω

Load Impedance 4

Tone Control Range Bass/ Mid-range/ Treble ±12 dB at 60 Hz/ 1 kHz/ 7.5 kHz

Frequency Response 40 Hz to 20 000 Hz

Line-Out Level/Impedance 2.5 V/20 k

Subwoofer-Out Level/Impedance 2.5 V /20 k

Output Impedance 1 k

Other Terminal CD changer, AUX (auxiliary) input jack

TUNER SECTION

Frequency Range FM 87.5 MHz to 107.9 MHz (with channel interval set to 100 kHz or 200 kHz)

AM 530 kHz to 1 710 kHz (with channel interval set to 10 kHz)

FM Tuner Usable Sensitivity 11.3 dBf (1.0

50 dB Quieting Sensitivity 16.3 dBf (1.8

Alternate Channel Selectivity (400 kHz) 65 dB

Frequency Response 40 Hz to 15 000 Hz

Stereo Separation 35 dB

AM Tuner Sensitivity/Selectivity 20

CD PLAYER SECTION

Type Compact disc player

Signal Detection System Non-contact optical pickup (semiconductor laser)

Number of Channels 2 channels (stereo)

Frequency Response 5 Hz to 20 000 Hz

Dynamic Range 96 dB

Signal-to-Noise Ratio 98 dB

Wow and Flutter Less than measurable limit

MP3 Decoding Format: (MPEG1/2 Audio Layer 3) Max. Bit Rate: 320 kbps

WMA (Windows Media® Audio) Decoding Format Max. Bit Rate: 192 kbps

Power Requirement Operating Voltage DC 14.4 V (11 V to 16 V allowance)

Grounding System Negative ground

Allowable Operating Temperature 0

Dimensions(W (approx.)

Mass 1.4 kg (3.1 lbs) (excluding accessories)

H × D)

Installation Size 182 mm × 52 mm × 150 mm

Panel Size 188 mm

(4 Ω to 8 Ω allowance)

Ω

load (full scale)

Ω

load (full scale)

Ω

87.5 MHz to 108.0 MHz (with channel interval set to 50 kHz)

531 kHz to 1 602 kHz (with channel interval set to 9 kHz)

V/75 Ω)

V/35 dB

GENERAL

C to + 40°C (32°F to 104°F)

58 mm × 12 mm

)

Design and specifications are subject to change without notice.

1-2 (No.MA340)

1.1 Safety Precautions

SECTION 1

PRECAUTIONS

Burrs formed during molding may be left over on some parts of the chassis. Therefore, pay attention to such burrs in the case of preforming repair of this system.

Please use enough caution not to see the beam directly or touch it in case of an adjustment or operation check.

(No.MA340)1-3

1.2 Preventing static electricity

Electrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is discharged, can destroy the laser diode in the traverse unit (optical pickup). Take care to prevent this when performing repairs.

1.2.1 Grounding to prevent damage by static electricity

Static electricity in the work area can destroy the optical pickup (laser diode) in devices such as CD players. Be careful to use proper grounding in the area where repairs are being performed.

(1) Ground the workbench

Ground the workbench by laying conductive material (such as a conductive sheet) or an iron plate over it before placing the traverse unit (optical pickup) on it.

(2) Ground yourself

Use an anti-static wrist strap to release any static electricity built up in your body.

(caption) Anti-static wrist strap

Conductive material (conductive sheet) or iron plate

(3) Handling the optical pickup

• In order to maintain quality during transport and before installation, both sides of the laser diode on the replacement optical pickup are shorted. After replacement, return the shorted parts to their original condition. (Refer to the text.)

• Do not use a tester to check the condition of the laser diode in the optical pickup. The tester's internal power source can easily destroy the laser diode.

1.3 Handling the traverse unit (optical pickup)

(1) Do not subject the traverse unit (optical pickup) to strong shocks, as it is a sensitive, complex unit. (2) Cut off the shorted part of the flexible cable using nippers, etc. after replacing the optical pickup. For specific details, refer to the

replacement procedure in the text. Remove the anti-static pin when replacing the traverse unit. Be careful not to take too long a

time when attaching it to the connector. (3) Handle the flexible cable carefully as it may break when subjected to strong force. (4) It is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not turn it.

1.4 Attention when traverse unit is decomposed

*Please refer to "Disassembly method" in the text for the CD pickup unit.

• Apply solder to the short land before the flexible wire is disconnected from the connector on the CD pickup unit. (If the flexible wire is disconnected without applying solder, the CD pickup may be destroyed by static electricity.)

• In the assembly, be sure to remove solder from the short land after connecting the flexible wire.

Pickup

Wires

Push switch

1-4 (No.MA340)

Base board

Frame

Flexible wire

Connector

CD mechanism assembly

Pickup

+ 8 hidden pages