JVC KD-LH3105 Service Manual

SERVICE MANUAL

CD RECEIVER

4983920035

KD-LH3105

Area Suffix

U ------- Other Areas

TABLE OF CONTENTS

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

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

3 Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

4 Description of major ICs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

No.49839

2003/5

SPECIFICATION

AUDIO AMPLIFIER SECTION

TUNER SECTION Frequency Range FM 87.5 MHz to 108.0 MHz

CD PLAYER SECTION Type Compact disc player

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

Maximum Power Output Front 50 W per channel

Rear 50 W per channel

Continuous Power Output (RMS)

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

Equalizer Control Range Frequencies 60 Hz, 150 Hz, 400 Hz, 1 kHz, 2.4 kHz, 6 kHz, 12 kHz

Level ±10 dB

Frequency Response 40 Hz to 20 000 Hz

Signal-to-Noise Ratio 70 dB

Line-In Level/Impedance 1.5 V/20 kΩ load Line-Out Level/Impedance 4.0 V/20 kΩ load (full scale) Output Impedance 1 kΩ

Subwoofer-Out Level/ Impedance

[FM Tuner] Usable Sensitivity 11.3 dBf (1.0 µV/75 Ω)

[AM Tuner] Sensitivity 20 µV

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

Grounding System Negative ground

Allowable Operating Temperature

Dimensions

(W × H × D)

2.0 V/20 kΩ load (full scale)

AM 531 kHz to 1 602 kHz

50 dB Quieting Sensitivity

Alternate Channel Selectivity (400 kHz)

Frequency Response 40 Hz to 15 000 Hz

Stereo Separation 35 dB

Capture Ratio 1.5 dB

Selectivity 35 dB

0°C to +40°C

Installation Size (approx.)

Panel Size (approx.) 188 mm × 58 mm × 12 mm

Mass (approx.) 1.4 kg (excluding accessories)

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.

16.3 dBf (1.8 µV/75 Ω)

65 dB

182 mm × 52 mm × 150 mm

Design and specifications are subject to change without notice.

1-2 (No.49839)

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.49839)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.

Short-circuit point

(Soldering)

Flexible wire

1-4 (No.49839)

Short-circuit point

Pickup

SECTION 2

Disassembly method

2.1 Main body

2.1.1 Removing the front panel assembly (See Fig.1)

(1) Push the detach button in the lower left part of the front

panel assembly and remove the front panel assembly.

2.1.2 Removing the bottom cover (See Fig.2)

• Prior to performing the following procedure, remove the front

panel assembly as required. (1) Turn over the main body and release the two joints a, two

joints b and joint c.

Caution:

Do not damage the main board when releasing the joints using a screwdriver.

Front panel assembly

Detach button

Fig.1

Bottom cover

Joint b

Joint a

Joint b

Joint c

Fig.2

(No.49839)1-5

2.1.3 Removing the front chassis assembly (See Figs.3 and 4)

• Prior to performing the following procedures, remove the front

panel assembly and bottom cover. (1) Remove the two screws A on the both sides of the main

body. (See Fig.3.)

(2) Remove the two screws B on the front side of the main

body. (See Fig.4.)

(3) Release the two joints d and two joints e on the both sides

of the main body. (See Fig.3.)

Joint d

Front chassis assembly

Joint e

Fig.3

Front chassis assembly

Fig.4

2.1.4 Removing the heat sink (See Fig.5)

• Prior to performing the following procedure, remove the front

panel assembly as required. (1) Remove the two screws C and two screws D on the left

side of the main body.

2.1.5 Removing the rear bracket (See Fig.6)

• Prior to performing the following procedures, remove the bot-

tom cover. (1) Remove the three screws E, three screws F and three

screws G on the back side of the main body.

(2) Remove the rear bracket.

Reference:

During reassembly, before fixing the rear bracket onto the main body, insert the SUB WOOFER cable and LINE IN cable into the slots.

Heat sink

Fig.5

Rear bracket

1-6 (No.49839)

Insert SUB WOOFER cable and LINE IN cable into the slots.

Fig.6

2.1.6 Removing the main board

(See Fig.7)

• Prior to performing the following procedures, remove the front

panel assembly, bottom cover, front chassis assembly, heat sink and rear bracket. (1) Remove the two screws H attaching the main board. (2) Disconnect the connector CN601 and remove the main

board in an upward direction.

2.1.7 Removing the mecha control board

(See Fig.8)

• Prior to performing the following procedures, remove the front

panel assembly, bottom cover, front chassis assembly, heat sink, rear bracket and main board. (1) Remove the five screws J attaching the mecha control

board. (2) Disconnect the card wire from the mecha connector. (3) Move the mecha control board in the direction of the arrow

to release it from the joint f.

Joint f

Mecha connector

CN601

Main board

Fig.7

2.1.8 Removing the CD mechanism assembly (See Fig.9)

• Prior to performing the following procedure, remove the front

panel assembly, bottom cover, front chassis assembly, heat sink, rear bracket, main board and mecha control board. (1) Remove the three screws K attaching the CD mechanism

assembly to the top chassis.

Card wire

Mecha control board

CD mechanism assembly

Top chassis

Fig.8

Top chassis

Fig.9

(No.49839)1-7

2.1.9 Removing the front board (See Figs.10 to 12)

• Prior to performing the following procedures, remove the front

panel assembly. (1) Remove the five screws L attaching the rear cover on the

back side of the front panel assembly. (See Fig.10.)

(2) Release the eight joints g, remove the rear cover from the

front panel assembly. (See Fig.11.)

(3) Take out the front board. (See Fig.12.)

Front panel assembly

Rear cover

Front board

Rear cover

Fig.10

Joint

Fig.11

Joint g

1-8 (No.49839)

Fig.12

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.49839)1-9

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

1-10 (No.49839)

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.49839)1-11

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

1-12 (No.49839)

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.49839)1-13

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

1-14 (No.49839)

2.2.7 Removing the pickup unit

(See Figs.14 to 18)

• Prior to performing the following procedure, remove the top

cover, connector board and chassis unit. (1) Remove the screw D and pull out the pu. shaft holder from

the pu. shaft. (2) Remove the screw E attaching the feed sw. holder. (3) Move the part e of the pickup unit upward with the pu. shaft

and the feed sw. holder, then release the joint f of the feed

sw. holder in the direction of the arrow. The joint g of the

pickup unit and the feed rack is released, and the feed sw.

holder comes off. (4) Remove the pu. shaft from the pickup unit. (5) Remove the screw F attaching the feed rack to the pickup

unit.

Part e

Feed rack

Pickup unit

Feed sw. holder

Fig.15

2.2.8 Reattaching the pickup unit (See Figs.14 to 17)

(1) Reattach the feed rack to the pickup unit using the screw F. (2) Reattach the feed sw. holder to the feed rack while setting

the joint g to the slot of the feed rack and setting the joint f of the feed rack to the switch of the feed sw. holder correctly.

(3) As the feed sw. holder is temporarily attached to the pickup

unit, set to the gear of the joint g and to the bending part of the chassis (joint h) at a time.

CAUTION:

Make sure that the part i on the underside of the feed rack is certainly inserted to the slot j of the change lock

lever. (4) Reattach the feed sw. holder using the screw E. (5) Reattach the pu. shaft to the pickup unit. Reattach the pu.

shaft holder to the pu. shaft using the screw D.

Feed sw. holder

Joint f

Joint g

Feed sw. holder

Pickup unit

Part i

Slot j

Pu. shaft

Pickup unit

Joint f

Joint h

Fig.16

Feed rack

Pu. shaft holde

Pu. shaft

Pu. shaft holder

Pickup unit

Fig.14

Part e

Joint g

Feed rack

Fig.17

Pickup unit

Joint g

Joint f

Feed sw. holder

Fig.18

(No.49839)1-15

2.2.9 Removing the trigger arm

(See Figs.19 and 20)

• Prior to performing the following procedure, remove the top cover, connector board and clamper unit. (1) Turn the trigger arm in the direction of the arrow to release

the joint k and pull out upward.

CAUTION:

When reassembling, insert the part m and n of the trigger arm into the part p and q at the slot of the chassis rivet assembly respectively and join the joint k at a time.

Chassis rivet assembly

Trigger arm

Chassis

rivet

assembly

Joint k

Trigger arm

Fig.19

Part p

Part q

Part m

Part n

2.2.10 Removing the top plate assembly

(See Fig.21)

• Prior to performing the following procedure, remove the top cover, connector board, chassis unit, and clamper assembly. (1) Remove the screw H. (2) Move the top plate assembly in the direction of the arrow to

release the two joints r.

(3) Unsolder the wire marked s if necessary.

Fig.20

Top plate assembly

Joints

Fig.21

1-16 (No.49839)

2.2.11 Removing the mode sw. / select lock arm (See Figs.22 and 23)

• Prior to performing the following procedure, remove the top

plate assembly. (1) Bring up the mode sw. to release from the link plate (joint t)

and turn in the direction of the arrow to release the joint u. (2) Unsolder the wire of the mode sw. marked s if necessary. (3) Turn the select lock arm in the direction of the arrow to re-

lease the two joints v. (4) The select lock arm spring comes off the select lock arm at

the same time.

Link plate

Joint u

Fig.22

Joint t

Mode sw.

Select lock arm

Top plate

Select lock arm

Link plate

Select lock arm

Fig.23

Top plate

Hook w

Select lock arm spring

Joints v

(No.49839)1-17

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