JVC KD-LX555R Service Manual

SERVICE MANUAL

CD RECEIVER

4979320034

KD-LX555R

STDM

SOURCE

KD-LX555R

Area Suffix

E ------ Continental Europe

TABLE OF CONTENTS

1 Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Disassembly method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3 Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

4 Description of major ICs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

No.49793

2003/5

SPECIFICATION

AUDIO AMPLIFIER SECTION Maximum Power Output Front 50 W per channel

Rear 50 W per channel

Continuous Power Output (RMS) Front 19 W per channel into 4 Ω, 40 Hz to 20 000 Hz

at no more than 0.8% total harmonic distortion.

Rear 19 W per channel into 4 Ω, 40 Hz to 20 000 Hz

at no more than 0.8% total harmonic distortion.

Load Impedance 4 Ω (4 Ω to 8 Ω allowance)

Equalizer Control Range: LOW ±12 dB (50 Hz, 80 Hz, 120 Hz)

MID ±12 dB (700 Hz, 1 kHz, 2 kHz)

HIGH ±12 dB (8 kHz, 12 kHz)

Frequency Response 40 Hz to 20 000 Hz

Signal-to-Noise Ratio 70 dB

Line-Out Level/Impedance 2.0 V/20 kΩ load (full scale) Output Impedance 1 kΩ

TUNER SECTION Frequency Range FM 87.5 MHz to 108.0 MHz

AM (MW) 522 kHz to 1 620 kHz

(LW) 144 kHz to 279 kHz

[FM Tuner]

Usable Sensitivity 11.3 dBf (1.0 µV/75 Ω) 50 dB Quieting Sensitivity 16.3 dBf (1.8 µV/75 Ω)

Alternate Channel Selectivity (400 kHz) 65 dB

Frequency Response 40 Hz to 15 000 Hz

Stereo Separation 30 dB

Capture Ratio 1.5 dB

[MW Tuner]

Sensitivity 20 µV

Selectivity 35 dB

[LW Tuner]

Sensitivity 50 µV

CD PLAYER SECTION Type Compact disc player

Signal Detection System

Number of channels 2 channels (stereo)

Frequency Response 5 Hz to 20 000 Hz

Dynamic Range 98 dB

Signal-to-Noise Ratio 102 dB

Wow and Flutter Less than measurable limit

MP3 decoding format

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

Grounding System Negative ground

Allowable Operating Temperature 0°C to +40°C Dimensions (W × H × D) Installation Size 182 mm × 52 mm × 160 mm

Panel Size 188 mm × 58 mm × 8 mm

Mass 1.8 kg (excluding accessories)

Non-contact optical pickup (semiconductor laser)

MPEG1/2 Audio Layer 3 Max. Bit Rate:320 Kbps

Design and specifications are subject to change without notice.

1-2 (No.49793)

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.49793)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 CDpickup may be destroyed by static electricity.)

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

1-4 (No.49793)

Connector board

Soldering

SECTION 2

Disassembly method

2.1 Main body

2.1.1 Removing the top chassis (See Fig.1~5)

(1) Remove the two screws A attaching the bottom cover to

the top chassis on the bottom of the body.

(2) Remove the two screws B attaching the top chassis on

both sides of the body.

(3) Remove the screw C and the thee screws D attaching the

heat sink on the left side of the body.

(4) Remove the two screws E and the screw F on the back of

the body. (5) Remove the two screws G on the upper side of the body. (6) Move the top chassis upward and disconnect the CD

mechanism connector from the main board connector by

pulling it. Remove the top chassis from the body.

Bottom cover

Heat sink

Fig.3

Top chassis

Fig.1

Top chassis

Fig.2

Fig.4

Top chassis

Fig.5

(No.49793)1-5

2.1.2 Removing the front panel assembly (See Fig.6~8)

• Prior to performing the following procedure, remove the top

chassis assembly. (1) Disconnect the flexible harness from connector CN701 on

the main board assembly.

(2) Remove the four screws H attaching the front panel as-

sembly on both sides of the body. Remove the front panel toward the front.

CN701

Front panel assembly

Fig.6

Front panel assembly

Fig.7

Front panel assembly

CN701

Fig.8

1-6 (No.49793)

2.1.3 Removing the Front Board

(See Fig.9)

• Prior to performing the following procedure, remove the top

chassis assembly and the front panel assembly. (1) Remove the four screws I attaching the front board on the

back of the front panel assembly and release the eight joints a.

2.1.4 Removing the lifter unit

(See Fig.10)

• Prior to performing the following procedure, remove the top

chassis assembly and the front panel assembly. (1) Disconnect the harness from connector CN830 and CN831

on the main board.

(2) Remove the four screws J and detach the lifter unit from

the bottom cover.

CN830

Joints a

Fig.9

CN831

Fig.10

Lifter unit assembly

(No.49793)1-7

2.1.5 Removing the feed motor (L) (See Fig.11)

• Prior to performing the following procedure, remove the lifter

unit. (1) Remove the washer attaching the clutch assembly and de-

tach the clutch assembly from the shaft of the lifter unit.

(2) Remove the two screws K attaching the feed motor (L).

Lifter unit assembly

Washer

2.1.6 Removing the feed motor (R) (See Fig.12)

• Prior to performing the following procedure, remove the lifter

unit. (1) Remove the washer attaching the clutch assembly and de-

tach the clutch assembly from the shaft of the lifter unit.

(2) Remove the two screws L attaching the feed motor (R).

Clutch assembly

Washer

Feed motor (L) assembly

Fig.11

Lifter unit assembly

Feed motor (R) assembly

Fig.12

1-8 (No.49793)

2.1.7 Removing the operation assembly

(See Fig.13~16)

• Prior to performing the following procedure, remove the top

chassis assembly, the front panel assembly and the lifer unit. (1) Disconnect the card wire from connector CN702 on the

main board and remove the operation assembly.

(2) Remove the three screws M attaching the right and left

brackets, which fix gears on both sides of the operation assembly.

(3) Remove the springs 5 and 6 from the operation assembly.

ATTENTION:

When reassembling, correctly engage the switch S651 and S652 on the main board and the right gear with the part b of the operation assembly.

Operation assembly

Fig.15

Bracket (L)

Spring 5

CN702

Operation assembly

Fig.13

Bracket (R)

Spring 6

S652

S651

S652

Bracket (R)

Operation assembly b

S651

Fig.16

Operation assembly b

Fig.14

(No.49793)1-9

2.1.8 Removing the operation switch board (See Fig.17~19)

• Prior to performing the following procedure, remove the oper-

ation assembly. (1) Remove the six screws N attaching the button panel on the

operation assembly.

(2) Release the bottom panel from the bottom base at the bot-

tom of the operation switch assembly five joint c and remove the bottom panel.

(3) Pull out the operation switch board from inside of the button

panel.

Button panel

Fig.17

Operation switch board

Button base

Button panel

Fig.18

Button panel

Fig.19

1-10 (No.49793)

2.1.9 Removing the MP3 board assembly

(See Fig.20,21)

• Prior to performing the following procedure, remove the top

chassis.

Caution:

Before disconnecting the card wire from connector CN601 on the MP3 board, solder the short-circuit point on the connector board in the CD mechanism assembly (Refer to Fig.20). (1) Disconnect the card wire from connector CN601 on the

MP3 board assembly.

(2) Remove the five screws O attaching the MP3 board as-

sembly and release the joint d and e.

Caution:

When reattaching the MP3 board, connect the card wire extending from the connector board to connector CN601 and unsolder the short-circuit point (Refer to Fig.21).

Connector board

Soldering

Fig.20

CN601

2.1.10 Removing the CD mechanism assembly

(See Fig.22)

(1) Remove the three screws P and the CD mechanism as-

sembly from the top chassis.

OOO

MP3 board

Fig.21

CD mechanism assembly

Fig.22

(No.49793)1-11

2.1.11 Removing the main board assembly (See Fig.23~25)

• Prior to performing the following procedure, remove the top

chassis. (1) Disconnect the flexible harness from connector CN701, the

card wire from CN702 on the main board and the harness from CN830 and CN831 respectively.

(2) Remove the three screws Q attaching the main board as-

sembly to the bottom cover on the upper side of the body.

(3) Remove the screw R attaching the rear panel and the bot-

tom cover on the back of the body. Move the main board in the direction of the arrow and release the two joints f. (At this point, the main board can be removed with the rear panel and the rear heat sink.)

(4) Remove the three screws S attaching the rear heat sink on

the back of the body.

(5) Remove the two screws T and the screw U attaching the

rear panel. Now, the main board assembly will be removed.

ATTENTION:

When reassembling, correctly engage the switch S651 and S652 on the main board and the right gear with the part b of the operation assembly (Refer to Fig.24).

CN830

Joint f

CN831

CN701

Joint f

CN702

Front panel assembly

Fig.23

S652

S651

Rear panel

Main board

USR

Fig.24

Rear heat sink

Fig.25

1-12 (No.49793)

2.2 CD Mechanism section

2.2.1 Removing the top cover

(See Figs.1 and 2)

(1) Remove the four screws A on the both side of the body. (2) Lift the front side of the top cover and move the top cover

backward to release the two joints a.

Top cover

Joints a

Fig.1

Fig.2

Top cover

(No.49793)1-13

2.2.2 Removing the connector board (See Figs.3 to 5)

CAUTION:

Before disconnecting the flexible wire from the pickup, solder the short-circuit point on the pickup. No observance of this instruction may cause damage of the pickup. (1) Remove the screw B fixing the connector board. (2) Solder the short-circuit point on the pickup. (3) Disconnect the flexible wire from the pickup. (4) Move the connector board in the direction of the arrow to

release the two joints b.

(5) Unsolder the wires on the connector board if necessary.

CAUTION:

Unsolder the short-circuit point after reassembling.

Connector board

Flexible wire

Wires

Joints b

Short-circuit point

Fig.3

Short-circuit point

(Soldering)

Pickup

Flexible wire

Frame

Pickup

Fig.4

Connector board

Fig.5

1-14 (No.49793)

2.2.3 Removing the DET switch

(See Figs.6 and 7)

(1) Extend the two tabs c of the feed sw. holder and pull out

the switch.

(2) Unsolder the DET switch wire if necessary.

DET

switch

Connector

board

Pickup

Fig.6

DET switch

Tab c

DET switch wire

Feed sw. holder

Fig.7

(No.49793)1-15

2.2.4 Removing the chassis unit

(See Figs.8 and 9)

• Prior to performing the following procedure, remove the top

cover and connector board. (1) Remove the two suspension springs (L) and (R) attaching

the chassis unit to the frame.

CAUTION:

• The shape of the suspension spring (L) and (R) are different. Handle them with care.

• When reassembling, make sure that the three shafts on the underside of the chassis unit are inserted to the dampers certainly.

Suspension spring (R)

Chassis unit

Suspension spring (L)

Frame

Suspension spring (R)

Chassis unit

Shafts

Damper

Suspension spring (L)

Fig.8

Shaft

Dampe

Frame

Fig.9

1-16 (No.49793)

2.2.5 Removing the clamper assembly (See Figs.10 and 11)

• Prior to performing the following procedure, remove the top

cover. (1) Remove the clamper arm spring. (2) Move the clamper assembly in the direction of the arrow to

release the two joints d.

Clamper arm spring

Joint d

Clamper assembly

Fig.10

Clamper arm spring

Chassis rivet assembly

Joint d

Clamper assembly

Chassis rivet assembly

Joint d

Fig.11

(No.49793)1-17

2.2.6 Removing the loading / feed motor assembly (See Figs.12 and 13)

• Prior to performing the following procedure, remove the top

cover, connector board and chassis unit. (1) Remove the screw C and move the loading / feed motor as-

sembly in the direction of the arrow to remove it from the chassis rivet assembly.

(2) Disconnect the wire from the loading / feed motor assembly

if necessary.

CAUTION:

When reassembling, connect the wire from the loading / feed motor assembly to the flame as shown in Fig.12.

Loading / feed motor assembly

Fig.12

Loading / feed motor assembly

Fig.13

1-18 (No.49793)

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