JVC KD-SX985 Service Manual

SERVICE MANUAL

CD RECEIVER

KD-SX985

Contents

Safety precaution Preventing static electricity Disassembly method Adjustment method

SOUND

ATT

SOURCE

VOL

Area Suffix

U Other Areas

1-2 1-3 1-4 1-19

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

1-20 1-22 1-22 1-23~44

No.49731

Jun. 2002

KD-SX985

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-SX985

Preventing static electricity

1.Grounding to prevent damage by 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.

2.About the earth processing for the destruction prevention 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.

2-1 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.

2-2 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

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.

4.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

CD mechanism ass’y

Damper bracket

Attention when traverse unit is decomposed

*Please refer to "Disassembly method" in the text for pick-up and how to detach the substrate.

1.Solder is put up before the card wire is removed from connector on the CD substrate as shown in Figure. (When the wire is removed without putting up solder, the CD pick-up assembly might destroy.)

2.Please remove solder after connecting the card wire with when you install picking up in the substrate.

Front bracket

Feed motor ass’y

FD screw

CD mechanism control board

Soldering

FD gear

Pickup unit

1-3

KD-SX985

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.

Front panel unit

Removing the bottom cover

(See Fig.2,3)

Turn the body upside down.

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

CAUTION:

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

Removing the front chassis (See Fig.4,5)

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

Remove the two screws A attaching the front chassis.

Joint a

Joint c

Bottom cover

Fig.1

Bottom cover

Joint b

Fig. 2

Joint b

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

Release the two joints d and the two joints e on the sides. remove the front chassis toward the front.

Joint d

1-4

Front chassis

Fig. 5

Joint e

Joint a

Joint c

Fig. 3

Front chassis

Fig.4

Removing the heat sink (See Fig.6)

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

Removing the rear panel (See Fig.7 )

Heat sink

Fig. 6

KD-SX985

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

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

Rear panel

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.

D D

CN101

Fig. 7

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

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

Main board assembly

Fig. 8

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KD-SX985

Removing the MP3 board

(See Fig.9)

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

Disconnect the wire from connector CN601on the MP3 board.

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

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.

CD mechanism assembly

Fig. 10

Top cover

1-6

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 h with the front panel and the rear cover.

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

~ 13)

KD-SX985

Fig. 11

Joint h

Front panel

Joint h

LCD & Key control board

Rear cover

Joint h

Fig. 12

Fig. 13

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KD-SX985

< 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

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

1-8

Flexible wire

Frame

Connector board

Joints b

Flexible wire

Short-circuit

Fig.3

Fig.4Fig.5

Pickup

Short-circuit point

(Soldering)

Pickup

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

KD-SX985

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

Suspension spring (R)

Suspension spring (L)

Shafts

Damper

Frame

Fig.8Fig.7

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KD-SX985

Removing the clamper assembly

(See Fig.9 and 10)

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

1-10

Loading / feed motor assembly

Fig.12Fig.11

KD-SX985

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

Feed rack

Joint f

Feed sw. holder

Fig.17Fig.16

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KD-SX985

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.

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.

1-12

Top plate assembly

Joints p

Fig.20

KD-SX985

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'

Joint r

Fig.25Fig.24

Joint s

Select lock arm

Point x

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KD-SX985

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

1-14

Link plate

Fig.26

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