JVC KDLH-7-R Service manual

SERVICE MANUAL

CD RECEIVER

KD-LH7R

SOUND

SOURCE

VOL

KD-LH7R

Contents

Safety precaution Preventing static electricity Important for laser products Disassembly method Adjustment method

1-2 1-3 1-4 1-5 1-20

Area Suffix

E ---- Continental Europe EX ------- Central Europe

Flow of functional operation unit TOC read Maintenance of laser pickup Replacement of laser pickup Description of major ICs

1-21 1-23 1-23 1-24

No.49724

Apr. 2002

KD-LH7R

Safety precaution

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.

1-2

KD-LH7R

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.

1.1. Grounding to prevent damage by static electricity

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

1.1.1. Ground the workbench

1. 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.

1.1.2. Ground yourself

1. 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

1.1.3. Handling the optical pickup

1. 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.)

2. 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.

1.2. 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

Short-circuit point

(Soldering)

Connector board

Joints b

Short-circuit

Pickup

DET switch

Flexible wire

Pickup

1-3

KD-LH7R

Important for laser products

1.CLASS 1 LASER PRODUCT

2.DANGER : Invisible laser radiation when open and inter lock

failed or defeated. Avoid direct exposure to beam.

3.CAUTION : There are no serviceable parts inside the Laser Unit. Do not disassemble the Laser Unit. Replace the complete Laser Unit if it malfunctions.

4.CAUTION : The compact disc player uses invisible laser radiation and is equipped with safety switches which prevent emission of radiation when the drawer is open and the safety interlocks have failed or are defeated. It is dangerous to defeat the safety switches.

VARNING : Osynlig laserstrålning är denna del är öppnad

och spårren är urkopplad. Betrakta ej strålen.

VARO : Avattaessa ja suojalukitus ohitettaessa olet

alttiina näkymättömälle lasersäteilylle.Älä katso säteeseen.

5.CAUTION : If safety switches malfunction, the laser is able to function.

6.CAUTION : Use of controls, adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure.

CAUTION

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

ADVARSEL : Usynlig laserstråling ved åbning , når

sikkerhedsafbrydere er ude af funktion. Undgå udsættelse for stråling.

ADVARSEL : Usynlig laserstråling ved åpning,når

sikkerhetsbryteren er avslott. unngå utsettelse for stråling.

REPRODUCTION AND POSITION OF LABELS

WARNING LABEL

CLASS 1 LASER PRODUCT

DANGER : Invisible laser radiation when open and interlock or defeated. AVOID DIRECT EXPOSURE TO BEAM (e)

ADVARSEL :Usynlig laserstråling ved åbning , når sikkerhedsafbrydere er ude af funktion. Undgå udsæt telse for stråling. (f)

VARNING : Osynlig laserstrålning är denna del är öppnad och spårren är urkopplad. Betrakta ej strålen. (s)

VARO : Avattaessa ja suojalukitus ohitettaessa olet alttiina näkymättömälle lasersäteilylle.Älä katso säteeseen. (d)

1-4

Disassembly method

Removing the front panel unit

(See Fig.1)

Press the release switch and remove the front panel unit in the direction of the arrow.

Removing the front chassis

(See Fig.2 ~ 4)

Remove the two screws A attaching the front chassis.

KD-LH7R

Front panel unit

Fig.1

Remove the two screws B on each side of the body.

Release the two joints a and the two joints b on the sides. Release the two joints c at the bottom and remove the front chassis toward the front.

Joint c

Joint a

Fig.2

Front chassis

Fig. 3

Front chassis

Joint b

Fig.4

Removing the heat sink (See Fig.5)

Remove the four screws C attaching the heat sink on the left side of the body, and remove the heat sink.

Heat sink

Fig. 5

1-5

KD-LH7R

Removing the bottom cover (See Fig.6)

Prior to performing the following procedure, remove the front chassis and the heat sink.

Turn the body upside down.

Insert a screwdriver to the two joints d and two joints e on both sides of the body and the joint f on the back of the body, then detach the bottom cover from the body.

CAUTION:

When disengaging the joint f using a screwdriver, do not damage or break the board.

Removing the rear panel (See Fig.7 )

Prior to performing the following procedure, remove the front chassis, the heat sink and bottom cover.

Joint d

Joint f

Rear panel

Bottom cover

Joint e

Fig. 6

Remove the six screws D attaching the rear panel and one screw E attaching the pine jack on the back of the body.

Removing the main amplifier board assembly

(See Fig.8)

Prior to performing the following procedure, remove the front chassis, the heat sink, bottom cover and the rear panel.

Remove the two screws F attaching the main amplifier board assembly on the top cover.

Fig. 7

Disconnect connector CN101 on the main amplifier board assembly from the cassette mechanism assembly.

1-6

Main board assembly

CN101

Fig. 8

KD-LH7R

Removing the MP3 board

(See Fig.9)

Prior to performing the following procedure, remove the top cover.

Disconnect the wire from connector CN601 on the MP3 board.

Remove the five screws G and the MP3 board, releasing the joint g and h.

CN601

Fig.9

Removing the CD mechanism assembly

(See Fig.10)

Prior to performing the following procedure, remove the front chassis, the heat sink, bottom cover and the main amplifier board assembly.

Remove the three screws H attaching the cassette mechanism assembly from the top cover.

Top cover

CD mechanism assembly

Fig. 10

1-7

KD-LH7R

Removing the (LCD & key) control switch

board (See Fig.11

Prior to performing the following procedure, remove the front panel assembly.

Remove the four screws I attaching the rear cover on the back of the front panel assembly.

Unjoint the nine joints i with the front panel and the rear cover.

Remove the control switch board on the back of the front panel.

~ 13)

Fig. 11

Front panel

Joint i

LCD & Key control board

Joint i

Rear cover

Joint i

Fig. 12

1-8

Fig. 13

< CD mechanism section >

Removing the top cover

(See Fig.1 and 2)

Remove the two screws A on each side of the body.

Lift the front side of the top cover and move the cover backward to release the two joints a.

Removing the connector board

(See Fig.3 to 5)

Top cover

KD-LH7R

Joints a

CAUTION:

Remove the screw B fixing the connector board.

Solder the short-circuit point on the connector board. Disconnect the flexible wire from the pickup.

Move the connector board in the direction of the arrow to release the two joints b.

Unsolder the wire on the connector board if necessary.

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.

Unsolder the short-circuit point after reassembling.

Fig.1

Joints a

Top cover

Fig.2

DET switch

Flexible wire

Frame

Connector board

Joints b

Flexible wire

Short-circuit

Fig.3

Fig.4Fig.5

Pickup

Short-circuit point

(Soldering)

Pickup

1-9

KD-LH7R

Removing the DET switch

(See Fig.3 and 6)

Extend the two tabs c of the feed sw. holder and pull out the switch.

Unsolder the DET switch wire if necessary.

Removing the chassis unit

(See Fig.7 and 8)

Prior to performing the following procedure, remove the top cover and the connector board.

Connector board

Joints b

Short-circuit

Fig.3

DET switch

Pickup

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.

CAUTION:

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

Chassis unit

Suspension spring (R)

Suspension spring (L)

Frame

DET switch

Chassis unit

Tab c

Feed sw. holder

Tab c

Fig.6

Shaft

1-10

Suspension spring (R)

Suspension spring (L)

Shafts

Damper

Frame

Fig.8Fig.7

Removing the clamper assembly

(See Fig.9 and 10)

KD-LH7R

Prior to performing the following procedure, remove the top cover.

Remove the clamper arm spring.

Move the clamper assembly in the direction of the arrow to release the two joints d.

Removing the loading / feed motor assembly (See Fig.11 and 12)

Prior to performing the following procedure, remove the top cover, the connector board and the chassis unit.

Remove the screw C and move the loading / feed motor assembly in the direction of the arrow to remove it from the chassis rivet assembly.

Clamper arm spring

Joint d

Clamper assembly

Fig.9

Clamper arm spring

Chassis rivet assembly

Joint d

Clamper assembly

Joint d

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.11.

Chassis rivet assembly

Fig.10

Loading / feed motor assembly

Fig.12Fig.11

1-11

KD-LH7R

Removing the pickup unit

(See Fig.13 to 17)

Prior to performing the following procedure, remove the top cover, the connector board and the chassis unit.

Remove the screw D and pull out the pu. shaft holder from the shaft.

Remove the screw E attaching the feed sw. holder.

Move the part e of the pickup unit upward with the 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.

Remove the shaft from the pickup unit.

Remove the screw F attaching the feed rack to the pickup unit.

Reattaching the pickup unit

(See Fig.13 to 16)

Joint f

Shaft

Joint e

Pu. shaft holder

Feed sw. holder

Pickup unit

Fig.13

Pickup unit

Joint f

Joint e

Reattach the feed rack to the pickup unit using the screw F.

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

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:

Reattach the feed sw. holder using the screw E.

Reattach the shaft to the pickup unit. Reattach the pu. shaft holder to the shaft using the screw D.

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.

Feed rack

Joint g

Feed sw. holder

Part i

Pickup unit

Slot j

Joint g

Feed sw. holder

Fig.14

Shaft

Joint f

Joint h

Fig.15

Pu. shaft holder

Pickup unit

1-12

Pickup unit

Feed rack

Joint f

Feed sw. holder

Fig.17Fig.16

Removing the trigger arm

(See Fig.18 and 19)

Prior to performing the following procedure, remove the top cover, the connector board and the clamper unit.

Turn the trigger arm in the direction of the arrow to release the joint k and pull out upward.

KD-LH7R

Joint k

Trigger arm

CAUTION:

When reassembling, insert the part l and

m of the trigger arm into the part n and o at the slot of the chassis rivet

assembly respectively and join the joint k at a time.

Chassis rivet assembly

Trigger arm

Fig.18

Part n

Part o

Part l

Part m

Fig.19

Removing the top plate assembly

(See Fig.20)

Prior to performing the following procedure, remove the top cover, the connector board, the chassis unit, and the clamper assembly.

Remove the screw H.

Move the top plate assembly in the direction of the arrow to release the two joints p.

Unsolder the wire marked q if necessary.

Top plate assembly

Joints p

Fig.20

1-13

KD-LH7R

Removing the select arm (L) / select lock arm (See Fig.21 and 22)

Prior to performing the following procedure, remove the top plate assembly.

Bring up the select arm (L) to release from the link plate (joint r) and turn in the direction of the arrow to release the joint s.

Unsolder the wire of the select arm (L) marked q if necessary.

Turn the select lock arm in the direction of the arrow to release the two joints t.

The select lock arm spring comes off the select lock arm at the same time.

Reassembling the select arm (L) / select lock arm (See Fig.23 to 25)

Select arm (R)

Joint z

Link plate spring

Top plate

Joint a'

Joint y

Link plate

Joint z

Joint s

Fig.21

Select lock arm

Joint b'

Joint r

Select arm (L)

Select lock arm

Top plate

Hook u

Select lock arm spring

Joints t

REFERENCE:

Reattach the select lock arm spring to the top plate

Reverse the above removing procedure.

and set the shorter end of the select lock arm spring to the hook u on the top plate.

Set the other longer end of the select lock arm spring to the boss v on the underside of the select lock arm, and join the select lock arm to the slots (joint t). Turn the select lock arm as shown in the figure.

Reattach the select arm (L) while setting the part r to the first peak of the link plate gear, and join the joint s.

CAUTION:

When reattaching the select arm (L), check if the points w and x are correctly fitted and if each part operates properly.

Joint r

Link plate

Select lock arm spring

Boss v

Select arm (R)

Joint a'

Fig.22

Hook u

Joint t

Select lock arm

Fig.23

Link plate spring

Select arm (L)

Joint b'

1-14

Joint r

Fig.25Fig.24

Joint s

Select lock arm

Point x

KD-LH7R

Removing the select arm (R) / link plate

(See Fig.21 and 22)

Prior to performing the following procedure, remove the top plate assembly.

Bring up the select arm (R) to release from the link plate (joint y) and turn as shown in the figure to release the two joints z and joint a’.

Move the link plate in the direction of the arrow to release the joint b’. Remove the link plate spring at the same time.

REFERENCE:

Before removing the link plate, remove the select arm (L).

Reattaching the Select arm (R) / link plate (See Fig.25 and 26)

REFERENCE:

Reverse the above removing procedure.

Select arm (R)

Joint z

Link plate spring

Top plate

Joint a'

Part y

Link plate

Joint z

Joint s

Fig.21

Select lock arm

Joint b'

Joint r

Select arm (L)

Select lock arm

Top plate

Hook u

Select lock arm spring

Reattach the link plate spring.

Reattach the link plate to the link plate spring while joining them at joint b’.

Reattach the part y of the select arm (R) to the first peak of the link plate while joining the two joints z with the slots. Then turn the select arm (R) as shown in the figure. The top plate is joined to the joint a’.

CAUTION:

When reattaching the select arm (R), check if the part c’ is correctly fitted and if each part operates properly.

Select arm (R)

Joint z

Link plate

Link plate spring

Joint a'

Part y

Fig.22

Joint b'

Joint z

Fig.25

Joints t

Select arm (L)

Select lock arm

Point x

Fig.26

Link plate

1-15

KD-LH7R

Removing the loading roller assembly

(See Fig.27 to 29)

Prior to performing the following procedure, remove the clamper assembly and the top plate assembly.

Push inward the loading roller assembly on the gear side and detach it upward from the slot of the joint d’ of the lock arm rivet assembly.

Detach the loading roller assembly from the slot of the joint e’ of the lock arm rivet assembly.

The roller guide comes off the gear section of the loading roller assembly.

Remove the roller guide and the washer from the shaft of the loading roller assembly.

Remove the screw I attaching the lock arm rivet assembly.

Push the shaft at the joint f’ of the lock arm rivet assembly inward to release the lock arm rivet assembly from the slot of the slide plate. Extend the lock arm rivet assembly outward and release the joint g’ from the boss of the chassis rivet assembly. The roller guide springs on both sides come off.

Roller guide

Washer

Loading roller assembly

Roller guide

Joint e'

Roller guide spring

Joint d'

Loading roller assembly

Roller guide spring

Lock arm rivet assembly

Fig.27

Loading roller assembly

Roller guide spring

CAUTION:

When reassembling, reattach the left and right roller guide springs to the lock arm rivet assembly before reattaching the lock arm rivet assembly to the chassis rivet assembly. Make sure to fit the part h’ of the roller guide spring (L) inside of the roller guide (Refer to Fig.30).

Roller guide

Washer

Roller shaft assembly

Joint h'

Loading roller assembly

Roller guide spring

Fig.28-1

Fig.28-2

Chassis rivet assembly

Boss

Slide plate

Roller guide spring

1-16

Frame

Loading roller

Roller guide spring

Lock arm rivet assembly

Joint f'

Part g'

Fig.29Fig.30

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Removing the loading gear (5), (6) and (7) (See Fig.31 and 32)

Prior to performing the following procedure, remove the top cover, the chassis unit and the top plate assembly.

Remove the screw J attaching the loading gear bracket. The loading gear (6) and (7) come off the loading gear bracket.

Pull out the loading gear (5).

Loading gear bracket

Loading gear (6)

Loading gear (5)

Loading gear (3)

Fig.31

Loading gear bracket

Loading gear (5)

Loading gear (6)

Loading gear (7)

Fig.32

1-17

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Removing the gears (See Fig.33 to 36)

Prior to performing the following procedure, remove the top cover, the chassis unit, the top plate assembly and the pickup unit.

Pull out the feed gear.

Slot j'

Slide plate

Move the loading plate assembly in the direction of the arrow to release the slide plate from the two slots j’ of the chassis rivet assembly.

Detach the loading plate assembly upward from the chassis rivet assembly while releasing the joint k’. Remove the slide hook and the loading plate spring from the loading plate assembly.

Pull out the loading gear (2) and remove the change lock lever.

Remove the E-washer and the washer attaching the changer gear (2).

The changer gear (2), the changer gear spring and the adjusting washer come off.

Remove the loading gear (1).

Move the hang plate rivet assembly in the direction of the arrow to release from the three shafts of the chassis rivet assembly upward.

Detach the loading gear plate rivet assembly from the shaft of the chassis rivet assembly upward while releasing the joint l’.

Feed gear

Change plate rivet assembly

Shafts

E-washer

Loading plate assembly

Joint k' Slot j'

Fig.33

Joint l'

Loading gear (4)

Loading gear plate rivet assembly

Loading gear (2)

Loading gear (1)

Change gear (2)

10.

Pull out the loading gear (4).

Loading plate assembly

Loading plate spring

Slot j'

Chassis rivet assembly

Joint k'

Slide hook

Slide plate

Slot j'

E-washer

Washer

Loading gear (2)

Loading plate spring

Adjusting washer

Change plate rivet assembly

Chassis rivet assembly

Fig.34

Loading gear (1)

Loading gear (2)

Change lock lever

Loading gear (4)

Loading gear plate rivet assembly

Fig.36Fig.35

1-18

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Removing the turn table / spindle motor

(See Fig.37 and 38)

Prior to performing the following procedure, remove the top cover, the connector assembly and the chassis / clamper assembly.

Remove the two screws K attaching the spindle motor assembly through the slot of the turn table on top of the body.

Unsolder the wire on the connector board if necessary.

Turn table

Fig.37

Turn table

Spindle motor

Fig.38

1-19

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Adjustment method

Test instruments required for adjustment

1. Digital oscilloscope (100MHz)

2. AM Standard signal generator

3. FM Standard signal generator

4. Stereo modulator

5. Electric voltmeter

6. Digital tester

7. Tracking offset meter

8. Test Disc JVC :CTS-1000

9. Extension cable for check EXTSH002-22P 1

Standard measuring conditions Power supply voltage : DC14.4V(11V~16V allwance) Load impedance : 4 (4 to 8 allowance) Line-out Level / Impedance:

2.0V / 20 k load

How to connect the extension cable for adjusting

Standard volume position Balance and Bass &Treble volume : lndication"0" Loudness : OFF BBE : OFF Frequency Band FM 87.5MHz ~ 108.0MHz MW 522kHz ~ 1620 kHz LW 144kHz ~ 279kHz

Dummy load Exclusive dummy load should be used for AM,and FM. For FM dummy load,there is a loss of 6dB between SSG output and antenna input.The loss of 6dB need not be considered since direct reading of figures are applied in this working standard.

Extension cables

EXTSH002-22P

CN101

CN501

CD Mechanism

Main board

1-20

Flow of functional operation until TOC read

Power ON

• When the pickup correctly moves to the inner area of the disc

Set Function to CD

KD-LH7R

• When the laser diode correctly emits

Microprocessor

commands

FMO TC94A14FA "40"

FEED MOTOR

TERMINAL

+TERMINAL IC681 "4"

REST SW

• When correctly focused

FEO

TA2157FN "15"

Focus Servo Loop ON

Disc inserted

Pickup feed to the inner area

Laser emitted

Focus search

Disc rotates

RF signal eye-pattern remains closed

Tracking loop closed

RF signal eye-pattern opens

TOC readout

YES

Microprocessor

commands

TC94A14FA"38"

CN601"10"

"No disc"

display

• When the disc correctly rotates

Microprocessor commands

TN94A14FA "41"

Spindle motor (-) IC681 "7"

AccelerationAcceleration

0.5 Sec

Rough

Servo

0.5 Sec

Servo CLV

3.3V

Jump to the first track

Play

Tracking Servo Loop ON

• RF signal

Rough Servo Mode

CLV Servo Mode (ProgramArea)

CLV Servo Mode (Lead-In Area; Digital: 0)

1-21

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Feed Section

Is the voltage output at

IC621 pin "40" 5V or 0V?

Is 4V present at both

sides of the feed motor?

YES

Is the wiring for IC621

(56) ~ (64) correct?

Is 6V or 3V present at

IC681 "4" and "5"?

YES

Is 3.3V present at

IC681 pin "20"?

YES

Check the vicinity of

IC621.

Check the feed motor

connection wiring.

NONO

Check CD 8V

and 5V.

Check the feed motor.

Focus Section

When the lens is

moving:

Does the S-search

waveform appear at

IC681 pins "10" and "11"?

Spindle Section

Is the disk rotated?

YES

Does the RF signal

appear at TP1?

YES

Check IC681.

YES

Check the circuits in the

vicinity of IC681 pins

"8","9" and "15".

Check the pickup and

its connections.

Is 4V present at IC681

pins "7" and "6" ?

Check the spindle motor

and its wiring.

YES

NO NO

Is 4V present at IC621

pin "41" ?

YES

Check the vicinity of

IC681.

Check IC621 and

IC601.

Is the RF waveform at TP1

distorted?

Proceed to the Tracking

section

Tracking Section

When the disc is rotated

Is the tracking error signal

1-22

YES

at first:

Approx. 1.2 V

output at IC601 "11"?

YES

Check IC621.

Check the circuits in the

vicinity of IC601 "19"~"24"

or the pickup

Check the circuit in the

vicinity of IC601 pins

"2" ~ "12".

YESYES

Check the pickup and

its connections.

+ 51 hidden pages