JVC MXJ-570-V, MXJ-680-V Service manual

SERVICE MANUAL

COMPACT COMPONENT SYSTEM

MX-J570V MX-J680V

SOUND

VOCAL

MODE

MASKING

SLEEPECHO

FM MODE

V.INTRO

STILL

SUBTITLEHIGHLIGHT

TAPE

A/B

REC

START/STOP

ACTIVE BASS EX.

ON SCREEN

NEXTPREV

KEY CONTROL

FADE MUTING

RM—SMXJ570V REMOTE CONTROL

This illustration is MX-J570V

Each difference point

Model CD/DECK/RECEIVER SPEAKER

MX-J570V CA-MXJ570V

MX-J680V CA-MXJ680V

SP-MXJ570V SP-MXJ680V

SUPER VIDEO

Tray fitting

Silver

Area Suffix

US UX

Color

Panel

Silver & Blue Silver

Champagne-gold Champagne-gold

Net Front

Light blue

Gray

Singapore

Saudi Arabia

COMPACT

DIGITAL VIDEO

COMPACT

SUPER VIDEO

COMPACT

DIGITAL AUDIO

Contents

Safety precautions Important for laser products Preventing static electricity Precautions at disassembling and parts replacement Disassembly method Adjustment method

1-2 1-3 1-4

1-5 1-6 1-29

Diagnosis which uses extension wire method Flow of functional operation until TOC read Maintenance of laser pickup Replacement of laser pickup Description of major ICs

1-33

1-34 1-35 1-35 1-36

No.20853

Jul. 2000

MX-J570V/MX-J680V

Safety Precautions

1. This design of this product contains special hardware and many circuits and components specially for safety purposes. For continued protection, no changes should be made to the original design unless authorized in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Services should be performed by qualified personnel only.

2. Alterations of the design or circuitry of the product should not be made. Any design alterations of the product should not be made. Any design alterations or additions will void the manufacturer`s warranty and will further relieve the manufacture of responsibility for personal injury or proper ty damage resulting therefrom.

3. Many electrical and mechanical par ts in the products have special safety-related characteristics.

These characteristics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in the Parts List of Service Manual. Electrical components having such features are identified by shading on the schematics and by ( ) on the Parts List in the Service Manual. The use of a substitute replacement which does not have the same safety characteristics as the recommended replacement parts shown in the Parts List of Service Manual may create shock, fire, or other hazards.

4. The leads in the products are routed and dressed with ties, clamps, tubings, barriers and the like to be separated from live parts, high temperature parts, moving parts and/or sharp edges for the prevention of electric shock and fire hazard. When service is required, the or iginal lead routing and dress should be observed, and it should be confirmed that they have been returned to normal, after re-assembling.

5. Leakage currnet check (Electrical shock hazard testing) After re-assembling the product, always perform an isolation check on the exposed metal parts of the product (antenna terminals, knobs, metal cabinet, screw heads, headphone jack, control shafts, etc.) to be sure the product is safe to operate without danger of electrical shock. Do not use a line isolation transformer during this check.

Plug the AC line cord directly into the AC outlet. Using a "Leakage Current Tester", measure the leakage current from each exposed metal parts of the cabinet , particularly any exposed metal part having a return path to the chassis, to a known good earth ground. Any leakage current must not exceed 0.5mA AC (r.m.s.)

Alternate check method Plug the AC line cord directly into the AC outlet. Use an AC voltmeter having, 1,000 ohms per volt or more sensitivity in the following manner. Connect a 1,500 10W resistor paralleled by a 0.15 F AC-type capacitor between an exposed metal part and a known good earth ground. Measure the AC voltage across the resistor with the AC voltmeter. Move the resistor connection to eachexposed metal part, par ticularly any exposed metal part having a return path to the chassis, and meausre the AC voltage across the resistor. Now, reverse the plug in the AC outlet and repeat each measurement. voltage measured Any must not exceed 0.75 V AC (r.m.s.). This corresponds to 0.5 mA AC (r.m.s.).

0.15 F AC TYPE

1500 10W

Good earth ground

AC VOLTMETER (Having 1000 ohms/volts, or more sensitivity)

Place this probe on each exposed metal part.

Warning

1. This equipment has been designed and manufactured to meet international safety standards.

2. It is the legal responsibility of the repairer to ensure that these safety standards are maintained.

3. Repairs must be made in accordance with the relevant safety standards.

4. It is essential that safety critical components are replaced by approved parts.

5. If mains voltage selector is provided, check setting for local voltage.

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.

1-2

CAUTION

Important for laser products

MX-J570V/MX-J680V

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 de feated. 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 : Invisibie laser radiation when open and interlock or defeated. AVOID DIRECT EXPOSURE TO BEAM (e)



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

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

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



1-3

MX-J570V/MX-J680V

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

In the equipment which uses optical pick-up (laser diode), optical pick-up is destroyed by the static electricity of the work environment. 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

Attention when traverse unit is decomposed

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

CD changer mechanism

assembly

1. Remove the disk stopper and T. bracket on the CD changer mechanism assembly.

2. Disconnect the harness from connector on the CD motor board.

3. CD traverse unit is put up as shown in Fig.1.

4. Solder is put up before the card wire is removed from connector CN601 on the CD servo control board as shown in Fig. 2. (When the wire is removed without putting up solder, the CD pick-up assembly might destroy.)

5. Please remove solder after connecting the card wire with CN601 when you install picking up in the substrate.

1-4

CD traverse

unit

Flexible cable

Fig.1

Soldering

Fig.2

Precautions at disassembling and parts replacement

This model is charged with electricity on the power board even if the power cord is unplugged. Therefore, always discharge electricity in accordance with the steps given below before starting disassembling of the unit and/or replacement of parts.

While referring to the disassembling steps, remove the metal cover and the CD changer mechanism.

Set electrical resistances of 1kohm 1/4W to the places between the + and - terminals of the respective condensers C204 and C205 on the power board, and discharge electricity for 4 ~ 5 seconds.

Power board

C205

C204

MX-J570V/MX-J680V

1-5

MX-J570V/MX-J680V

Disassembly method

Removing the metal cover

(See Fig.1 to 3)

Remove the six screws A attaching the metal cover on the back of the body.

Remove the two screws B attaching the metal cover on both sides of the body.

Remove the metal cover from the body by lifting the rear part of the cover.

ATTENTION:

Do not break the front panel tab fitted to the metal cover.

Metal cover

Fig.1

Metal cover

Fig.2

Metal cover

Fig.3

1-6

MX-J570V/MX-J680V

CD changer mechanism board

CD changer mechanism assembly

Main board

CN868

Input / output board

CN871

CN870

Rear panel

Front panel assembly

Fig.5

Fig.6

Fig.4

Front panel assembly

CD changer mechanism assembly

Rear panel

CD Optical

digital output

terminal

TW100

CN102

Video CD board

Bracket

CLAW a

Fig.7

CD changer mechanism assembly

Video CD board

Video out board

Video CD board

CLAW b

CN100

CN101

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

For the card wire connecting the CD changer mechanism board and the main board, disconnect it from connector CN868 on the main board.

Remove the two screws C attaching the CD changer mechanism assembly on both sides of the body.

Remove the two screws D attaching the CD changer mechanism assembly to the rear panel. Remove the screw E attaching the AUX terminal on the back of the body.

Remove the screw F attaching the video out terminal on the back of the body. Then disconnect it from connector CN102 on the video CD board, and pull out the earth wire TW100 on the video CD board.

Pull the top of rear panel and the front panel assembly outward respectively, then remove the CD changer mechanism assembly and video out board by lifting the rear part of the CD changer mechanism assembly.

Removing the CD changer mechanism assembly (See Fig.4 to 6)

Prior to performing the following procedure, remove the CD changer mechanism assembly.

Reverse the CD changer mechanism assembly. Remove the two screws H attaching the bracket. Remove the screw I attaching the video CD board. Disconnect the card wire from connector CN100 and

CN101 on the video CD board. At first, remove the claw a. Then remove the claw b

while raising the video CD board in the direction of the arrow mark as figure. After removing the claw b, you can removing the video CD board by pulling it backward.

Removing the video CD board (See Fig.7)

1-7

MX-J570V/MX-J680V

Removing the front panel assembly

(See Fig.8 to 10)

Prior to performing the following procedure, remove the metal cover and the CD changer mechanism assembly.

Disconnect the card wire from connector CN865 on the main board and pull out the earth wire on the main board.

Disconnect the card wire from connector CN315 on the input / output board.

Disconnect the harness from connector CN912 on the input / output board.

Disconnect the harness from connectors CN900 and CN901 on the relay board on the back of the front panel assembly respectively.

Disconnect connector CN870 and CN871 on the input/output board from the main board respectively.

Front panel assembly

Fig.8

CN871

CN870

Remove the four screws J attaching the front panel assembly on the bottom of the body.

Release the two joints b and c on the lower part of the sides using a screwdriver, and remove the front panel assembly toward the front.

Main board

CN865

CN912

CN315

Joint b

Earth wire

Fig.9

Main board

CN865

Input / output board

Front panel assembly

1-8

Relay board

Joint c

CN900 CN901

Fig.10

Removing the Microphone terminal board assembly (See Fig.11 and 12)

Prior to performing the following procedure, remove the metal cover, CD changer mechanism assembly and the front panel assembly.

Pull out the MIC volume knob from the front side.

Remove the screw K attaching earth wire. then release the earth wire from the clamp on the upper part of the cassette mechanism assembly.

Remove the two screws L attaching the microphone terminal board assembly.

Remove the microphone terminal board assembly toward you.

MIC Volume knob

Microphone

terminal board

assembly

MX-J570V/MX-J680V

Fig.11

Removing the rolling panel assembly

(See Fig.12 and 13)

Prior to performing the following procedure, remove the microphone terminal boare .

Disconnect the harness from connector CN900 and CN906 on the relay board on the back of the rolling panel assembly.

Disconnect the harness from connector CN862, CN863, CN850, CN851 and CN815 on the main board respectively. Disconnect the card wire from connector CN880 on the main board.

Disconnect the card wire from connector CN869 and the harness from CN883 and CN884 on the main board respectively.

Remove the four screws M attaching the rolling panel assembly.

Main board

Relay board

CN900

Cassette mechanism assembly

CN883,CN884

Relay board

CN906

Fig.12

CN869

Rolling panel assembly

CN815

Main board CN850,CN851

Main board CN862,CN863

Remove the rolling panel assembly toward you.

ATTENTION:

For the harness which should be connected to connector CN869, CN883 and CN884 on the main board, get them through the slots under the rolling panel when reattaching the rolling panel assembly to the front panel (Refer to Fig.13)

Rolling panel assembly

Main board

CN880

Relay board

CN906

Fig.13

1-9

MX-J570V/MX-J680V

Removing the main board

(See Fig.14 and 15)

Prior to performing the following procedure, remove the front panel assembly, the microphone terminal board and the rolling panel assembly.

Disconnect the harness from connector CN867 on the main board.

Disconnect the card wire from connector CN879 on the main board (Before pulling out the card wire, stand the part d of CN879 as shown in Fig.15).

Remove the two screws N attaching the main board.

Removing the cassette mechanism assembly (See Fig.16)

Rolling panel assembly

CN867

CN879

Main board

Fig.14

CN879

Fig.15

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

Disconnect the card wire from connector CN306 on the cassette mechanism board.

Remove the eight screws O and P attaching the cassette mechanism assembly.

Pull out the cassette mechanism assembly toward you.

CN306

Cassette mechanism board

Fig.16

1-10

Prior to performing the following procedure, remove the front panel assembly, the microphone terminal board assembly and the rolling panel assembly.

Function board1 (See Fig.17)

Remove the two screws Q attaching the function board 1.

Function board2 (See Fig.17)

Remove the two screws R attaching the function board 2.

Bass-level regulator board (See Fig.18)

Pull out the bass-level knob on the front side of the front panel assembly and remove the nut attaching the bass-level regulator board.

Release the two joints e. Unsolder FW951 on the bass-level regulator board and disconnect the harness connected to the power switch board.

Main volume & headphone board (See Fig.18)

Pull out the volume knob on the front side of the front panel assembly and remove the nut attaching the main volume & headphone board.

Remove the two screws S attaching the main volume & headphone board on the back of the front panel assembly and release the two joints f.

Remove the screw P attaching the earth wire extending from the main volume & headphone board.

Unsolder FW850 on the main volume & headphone board and disconnect the harness connected to the eject switch board.

Removing the boards in the front panel assembly (See Fig.17 and 18)

Fig.17

Fig.18

Function

board 1

Function

board 2

FW850

FW951

Eject switch board

Joints f

Main volume & headphone board

Power switch board

Joints e

Bass-level regulator board

Cassette mechanism assembly

MX-J570V/MX-J680V

1-11

MX-J570V/MX-J680V

Power switch board (See Fig.19)

Remove the two screws T attaching the power switch board. Unsolder FW951 on the power switch board and disconnect the harness extending to the bass-level regulator board.

Eject switch board (See Fig.19)

Remove the four screws U attaching the eject switch board. Unsolder FW850 on the eject switch board and disconnect the harness extending to the main volume & headphone board.

Remote control port board (See Fig.19)

Remove the screw V attaching the remote control port board.

Removing the relay board and fixing board (See Fig.20)

Eject swith

board

FW850

Remote control port board

Fig.19

Power swith

board

FW951

Prior to performing the following procedure, remove the metal cover,CD changer mechanism assembly and the front panel assembly.

There is no need to remove the front panel assembly.

Disconnect the harness from connector CN900, CN901, CN905 and CN906 on the relay board on the back of the rolling panel assembly.

Remove the screw W attaching the relay board. Remove the relay board from the groove g.

Remove the screw X attaching the fixing board and remove the fixing board from the groove h.

CN900

CN901

Groove g

CN905

CN906

Rolling panel assembly

Fixing board

Groove h

Relay board

Fig.20

1-12

MX-J570V/MX-J680V

Prior to performing the following procedure, remove the metal cover and CD changer mechanism assembly.

Remove the two plastic rivets attaching the joint board, and remove the joint board.

Disconnect the card wire from connector CN1 on the tuner board.

Remove the two screws Y attaching the tuner board on the back of the body.

Removing the tuner board

(See Fig.21 and 22)

Prior to performing the following procedure, remove the metal cover and CD changer mechanism assembly.

Remove the two plastic rivets attaching the joint board, and remove the joint board.

Disconnect the card wire from connector CN315 on the input / output board.

Disconnect the harness from connector CN912 on the input / output board.

Remove the screw Z attaching the input / output board on the lower side of the body.

Disconnect connector CN612, CN870, CN871, CN711 and CN712 on the input / output board and pulling out them outward. Remove the input / output board from the body.

Removing the input / output board

(See Fig.21 and 22)

Fig.21

Fig.22

Tuner board

Plastic rivets

Joint board

Input / output board

Rear panel

CN1

CN871

CN870

CN711

CN712

CN315

Rear panel

CN912

CN612

1-13

MX-J570V/MX-J680V

Removing the rear cover / rear panel

(See Fig.23 to 26)

Prior to performing the following procedure, remove the metal cover and the CD changer mechanism assembly.

There is no need to remove the front panel assembly.

Remove the two screws A attaching the rear cover on the back of the body.

Remove the screw E attaching the AUX terminal board and the rear panel on the back of the body.

Remove the screw G attaching the digital output terminal.

Remove the seven screws B attaching the heat sink and the pre-amplifier board to the rear panel on the back of the body.

Remove the two screws C attaching the voltage selector on the back at the body.

Rear cover

CD optical

digital output

terminal

Rear panel

Fig.23

Remove the three screws D attaching the antenna terminal and the rear panel to the chassis base on the back of the body.

Release the two joints i and j on the rear panel bottom using a screwdriver, and detach the rear panel backward.

Rear panel

Fig.24

Rear panel

1-14

Fig.26

Joint j

Joint i

Fig.25

Prior to performing the following procedure, remove the metal cover, the CD changer mechanism assembly and the rear cover / rear panel.

There is no need to remove the front panel assembly.

Remove the input / output board (Refer to Fig.21 and

22). Disconnect the harness from connector CN713 on

the pre-amplifier board. Remove the two screws E attaching the heat sink to

the power & main amplifier board on the back of the body.

Remove the two screws F attaching the pre-amplifier board to the heat sink and detach them with the heat sink bracket.

Removing the pre-amplifier board / heat sink (See Fig.27 to 29)

Fig.27

Fig.28

Fig.29

Pre-amplifier board

CN713

Relay board

CN901

Pre-amplifier board

Power & main amplifier board

Heat sink

Pre-amplifier board

Bracket

MX-J570V/MX-J680V

1-15

MX-J570V/MX-J680V

Removing the power & main amplifier board (See Fig.30 and 31)

Prior to performing the following procedure, remove the metal cover, the CD changer mechanism assembly, the front panel assembly, the rear cover / rear panel, the tuner board, the input / output board and pre-amplifier board.

Remove the four screws G attaching the transf. on the power & main amplifier board through the upper side slots.

Remove the two plastic rivets fixing the power & main amplifier board.

Remove the cord stopper by pushing it upward.

Cut off the bands k and l fixing the power cord and unsolder the soldered part on the power & main amplifier board.

Power & main amplifier board

Plastic rivet

Fig.30

Plastic rivet

Power & main amplifier board

Cord stopper

Band k

Fig.31

Soldered part

Band l

1-16

MX-J570V/MX-J680V

Prior to performing the following procedure, remove the metal cover, CD changer mechanism assembly, the front panel assembly, the microphone terminal board assembly, the rolling panel assembly and the main board.

Remove the two screws H attaching the multi-control assembly on both sides.

Remove the multi-control assembly outward while pushing, pull the right and left hooks fixing multicontrol assembly outward respectively.

Removing the multi-control assembly

(See Fig.32 to 34)

Prior to performing the following procedure, remove the multi-control assembly.

Remove the four screws I attaching the cover and the bracket.

Pull out the right and left panel holders outward respectivery by releasing the tabs m outward.

Remove the cover and the bracket. Remove the four screws J attaching the multi-control

board.

Removing the multi-control board

(See Fig.35 to 37)

Multi-control assembly

Fig.35

Fig.36Fig.37

Fig.34

Fig.32

Fig.33

Multi-control assembly

Hook

Bracket

Cover

Bracket

Tab m

Panel holder

Multi-control board

1-17

MX-J570V/MX-J680V

Removing the drive motor assembly

(See Fig.38 to 40)

Remove the relay board / fixing board (Refer to Fig.20).

Remove the two screws K attaching the motor bracket and remove the motor lead staple n.

Remove the two screws L attaching the shaft bracket.

Remove the motor belt.

Remove the three screws M attaching the side bracket.

Remove the shaft assembly from the rolling panel assembly by lift up the shaft assembly upward.

CN900

CN901

Groove g

Relay board

Rolling panel assembly

Fixing board

Groove h

Fig.20

Remove the drive motor upward.

Side bracket

Relay board

Shaft bracket

Fig.38

Motor lead staple n

Fig.39

Fixing board

Motor bracket

Motor belt

1-18

Fig.40

Shaft assembly

Drive motor

Fig.39

MX-J570V/MX-J680V

Prior to performing the following procedure, remove the metal cover and the CD changer mechanism assembly.

Disconnect the card wire from connector CN101 and CN102 on the super VCD control board.

Remove the two plastic rivets attaching the super VCD control board.

Removing the super VCD control board

(See Fig.41)

Fig.42

CD changer

mechanism assembly

Super VCD control board

Plastic rivet Plastic rivet

CN101

CN102

1-19

MX-J570V/MX-J680V

Removing the CD Servo control board (See Fig.1)

1.Remove the metal cover.

2.Remove the CD changer mechanism assembly.

3.From bottom side the CD changer mechanism assembly, remove the two screws A retaining the CD servo control board.

4.Absorb the four soldered positions "a" of the right and left motors with a soldering absorber.

5.Pull out the earth wire on the CD changer mechanism assembly.

6.The two screws B is removed and C.B.holder is detached.

7.Disconnect the connector CN854 on the CD servo control board.

8.Disconnect the card wire CN601 and the connector CN801 on the CD servo control board.

CN854

CN651

CD servo control board

CN652

CN801

CN601

CN151

Removing the CD tray assembly (See Fig.2~4)

Remove the front panel assembly.

1. Remove the CD changer mechanism assembly.

2. Remove the CD Servo control board.

3. Remove the screw C retaining the lod stopper

4. (Only ver.J/C). From the T.bracket section "b" and clamper base

5. section "c" , remove both of the edges fixing the rod(See Fig.2 and 3). Remove the screw D retaining the disc stopper

6. (See Fig.3). Remove the three screws E retaining the T.bracket

7. (See Fig.3). Remove the screw F retaining the clamper assembly

8. (See Fig.3). From the left side face of the chassis assembly, remove

9. the one screw G retaining both of the return spring and lock lever(See Fig. 4).

10.

By removing the pawl at the section "d" fixing the return spring, dismount the return spring(See Fig.4).

11.

Remove the three lock levers(See Fig.4).

T.Braket

Disc stopper

Earth

wire

C.B.Holder

Fig.1

Clamper base

Rod

T.Braket

Fig.2

Lod stopper (Only ver.J/C)

Lock lever

Fig.4

1-20

Clamper ass'y

Fig.3

Return spring

MX-J570V/MX-J680V

11.

12.

Check whether the lifter unit stopper has been caught into the hole at the section "e" of CD tray assembly as shown in Fig.5. Make sure that the driver unit elevator is positioned as shown in Fig.6 from to the second or fifth hole on the left side face of the CD changer mechanism assembly.

Fig.5

Fig.7

Fig.6

Fig.8

Fig.9

[Caution]

In case the driver unit elevator is not at above position, set the elevator to the position as shown in Fig.7 by manually turning the pulley gear as shown in Fig.8.

13.

14.

15.

Manually turn the motor pulley in the clockwise direction until the lifter unit stopper is lowered from the section "e" of CD tray assembly(See Fig.8). Pull out all of the three stages of CD tray assembly in the arrow direction "f" until these stages stop (See Fig.6). At the position where the CD tray assembly has stopped, pull out the CD tray assembly while pressing the two pawls "g and g' " on the back side of CD tray assembly(See Fig.9). In this case, it is easy to pull out the assembly when it is pulled out first from the stage CD tray assembly.

CD tray assembly

Drive unit of elevator

CD tray assembly

Refer to Fig.7

Pawl

Chassis assembly

Pulley gear

Motor pulley

Pawl ,

CD tray assembly

Stopper

1-21

MX-J570V/MX-J680V

Removing the CD loading mechanism assembly(See Fig.10)

1.2.While turning the cams R1 and R2 assembly in the arrow direction "h" ,align the shaft "i" of the CD loading mechanism assembly to the position shown in Fig.10. Remove the four screws H retaining the CD loading mechanism assembly.

Removing the CD traverse mechanism (See Fig.11 and 12 )

For dismounting only the CD traverse mechanism

1. without removing the CD loading mechanism assembly, align the shaft "j" of the CD loading mechanism assembly to the position shown Fig.11 while turning the cam R1 and R2 assembly in the arrow direction "k" . By raising the CD loading mechanism assembly in the

2. arrow direction "l", remove the assembly from the lifter unit

Cam R1, R2 assembly

Cams R1, R2 assembly

Arrow

CD loading mechanism assembly

Fig.10

CD traverse mechanism

Arrow

Fig.11

Removing the CD pick unit (See Fig.13 )

Move the cam gear in the arrow direction "m" . Then, the CD pickup unit will be moved in the arrow direction "n" . According to the above step, shift the CD pickup unit to

2. the center position. While pressing the stopper retaining the shaft in the

3. arrow direction "o" , pull out the shaft in the arrow direction "p". After dismounting the shaft from the CD pickup unit,

4. remove the CD pickup unit

1-22

Lifter unit

Stopper

Shaft

Fig.12

CD Pickup unit

Shaft

Stopper

Fig.13

Arrow

CD loading

mechanism

Shaft

Cam gear

Removing the cam unit (See Fig.14 ~17 )

Remove the CD loading mechanism assembly.

While turning the cam gear "q", align the pawl "r" position of the drive unit to the notch position(Fig.16) on the cam gear "q". Pull out the drive unit and cylinder gear(See Fig.17).

3. While turning the cam gear "q", align the pawl "s"

4. position of the select lever to the notch position(Fig.18) on the cam gear "q". Remove the four screws J retaining the cam unit(cam

5. gear "q" and cams R1/R2 assembly)(See Fig.18).

MX-J570V/MX-J680V

Chassis assembly

CN801

CN802

Fig.14

Drive unit

Tray select switch board

Cylinder gear

CN804

Drive unit

Cam gear q

Fig.15

Cams R1, R2 assembly

Cam unit

Fig.16

Select lever

Fig.17

1-23

MX-J570V/MX-J680V

Removing the actuator motor and belt (See Fig.18~21)

Remove the two screws K retaining the gear bracket (See Fig.19).

While pressing the pawl "t" fixing the gear bracket in the arrow direction, remove the gear bracket (See Fig.19). From the notch "u section" on the chassis assembly

3. fixing the edge of gear bracket, remove and take out the gear bracket(See Fig. 20). Remove the belts respectively from the right and left

4. actuator motor pulleys and pulley gears(See Fig. 19). After turning over the chassis assembly, remove the

5. actuator motor while spreading the four pawls "v" fixing the right and left actuator motors in the arrow direction(See Fig. 21).

[Note]

When the chassis assembly is turned over under the conditions wherein the gear bracket and belt have been removed, then the pulley gear as well as the gear, etc. constituting the gear unit can possibly be separated to pieces. In such a case, assemble these parts by referring to the assembly and configuration diagram in Fig. 22.

Chassis assembly

Pulley gear

Gear bracket

Belt

Motor pulley

Fig.18

Actuator motor

Pulley gear Belt Motor pulley

Pawl

Gear bracket

Fig.19

Assembly and Configuration Diagram

Pulley gear

Gear B

Fig.20

Pulley gear

Gear B

Cylinder gear

1-24

Gear C

Select gear

Gross gear L

Fig.21

Gross gear U

Gear C

MX-J570V/MX-J680V

Fig.22

[Caution]

To reassemble the cylinder gear, etc.with the cam unit (cam gear and cans R1/R2 assembly), gear unit and drive unit, align the position of the pawl "x" on the drive unit to that of the notch on the cam gear "q". Then, make sure that the gear unit is engaged by turning the cam gear "q" (See Fig. 24).

Removing the cams R1/R2 assembly and cam gear q(See Fig.22)

Remove the slit washer fixing the cams R1 and R2 assembly. By removing the two pawls "w" fixing the cam R1, separate R2 from R1. Remove the slit washer fixing the cam gear "q". Pull out the cam gear "q" from the C.G. base assembly.

Removing the C.G. base assembly (See Fig.22 and 23)

Remove the three screws L retaining the C.G. base assembly.

Fig.23

Slit washer

Pawl

Cam R2

Slit washer

Cam gear q

Cam switch board

C.G. base assembly

Cam R1

Pawl

Cam gear q

Notch

Cylinder gear

Gear bracket

Cam R1, R2 assembly

Gear unit

Drive unit

Pawl

1-25

MX-J570V/MX-J680V

< Cassette mechanism section >

Removing the playback,recording and eraser heads (See Fig.1~3)

1. While shifting the trigger arms seen on the right side of the head mount in the arrow direction,turn the flywheel R in counterclockwise direction until the head mount has gone out with a click (See Fig. 1).

2. When the flywheel R is rotated in counterclockwise direction, the playback head will be turned in counterclockwise direction from the position in Fig.2 to that in Fig.3.

3. At this position, disconnect the flexible P.C.board (outgoing from the playback head) from the connector CN301 on the head amp. and mechanism control P.C. board.

4. After dismounting the FPC holder,remove the flexible P.C.board.

5. Remove the flexible P.C.board from the chassis base.

6. Remove the spring "a" from behind the playback head.

7. Loosen the reversing azimuth screw retaining the playback head.

8. Take out the playback head from the front of the head mount.

9. The recording and eraser heads should also be removed similarly according to Steps 1~8 above.

Reassembling the playback, recording

and eraser heads (See Fig.2,3)

Cassette mechanism

Fig.1

Playback/Recording & eraser head

Flexible P.C.board

CN301

Head amplifier & mechanism control P.C. board

Fig.2

Flywheel R

Trigger armHead mount

(Mechanism A side)

Spring "a"

Trigger arm

Flywheel R

(Mechanism A side)

1. Reassemble the playback head from the front of the head mount to the position as shown in Fig.3.

2. Fix the reversing azimuth screw.

3. Set the spring a from behind the playback head.

4. Attach the flexible P.C.board to the chassis base, and fix it with the FPC holder as shown in Fig.3.

5. The recording and eraser heads should also be reassembled similarly according to Steps 1~4 above.

1-26

Playback head

Spring "a"

FPC holder

Fig.3

Reversing azimuth screw

Head mount

Flexible P.C.board

CN302

Head amplifier & mechanism control P.C. board

(Mechanism B side)

Removing the head amp.and mechanism control P.C.board (See Fig. 4)

MX-J570V/MX-J680V

1.Remove the cassette mechanism assembly.

2.After turning over the cassette mechanism assembly,remove the five screws "A" retaining the head amp. and mechanism control P.C. board

3.Disconnect the connectors CN303 and CN304 on the P.C.Board and the connectors CN1 on both the right and left side reel pulse P.C.Boards.

4.When necessary, remove the 4pin parallel wire soldered to the main motor

Removing the capstan motor assembly

1.Remove the six screws "B" retaining capstan motor assembly (See Fig. 5).

2.While raising the capstan motor, remove the capstan belts A and B respectively from the motor pulley (See Fig. 6).

Flexible board

Head amplifier & mechanism control board

CN304

CN302 CN301

Flexible board

CN303

Fig.4

Capstan motor assembly

Caution 1: Be sure to handle the capstan belts so carefully that these belts will not be stained by grease and other foreign matter. Moreover, these belts should be hand while referring to the capstan belt hanging method.

Capstan belt A

BBBB

Fig.5

Capstan motor

Capstan belt B

Capstan belt A

Capstan belt B

Motor pulley

Fig.7 Fig.6

1-27

MX-J570V/MX-J680V

Removing the capstan motor (See Fig. 8)

From the joint bracket, remove the two screws "C" retaining the capstan motor.

Removing the flywheel (See Fig. 9,10)

1.Remove the head amp. and mechanism control

P.C.Board.

2.Remove the capstan motor assembly.

3.After turning over the cassette mechanism, remove

the slit washers "a" and "b" fixing the capstan shafts R and L, and pull out the flywheels R and L respectively from behind the cassette mechanism.

Capstan motor

Joint bracket

Fig.8

Flywheel R Flywheel L

Fig.10

Removing the reel pulse P.C.board and solenoid (See Fig. 11)

1.Remove the five pawls (c,d,e,f,g) retaining

the reel pulse P.C.Board.

2.From the surface of the reel pulse P.C.Board parts,

remove the two pawls "h" and "i" retaining the solenoid.

Solenoid

Slit washer "a"

Fig.9

Slit washer "b"

Reel pulse board

1-28

Solenoid

Fig.11

Adjustment method

Measurement instruments required for a djustment

1. Low frequency oscillator, This oscillator should have a capacity to output 0dBs to 600ohm at an oscillation frequency of 50Hz-20kHz.

2. Attenuator impedance : 600ohm

3. Electronic voltmeter

4. Frequency counter

5. Wow flutter meter

6. Test tape VTT712 : For Tape speed and wow flutter ( 3kHz) VTT724 : For Reference level (1kHz) TMT7036 : For Head angle(10kHz),Play back frequency characteristics(1kHz),and dubbing frequency characteristics(63,1,10kHz) Because of frequency-mixed tape with 63,1k,10k and 14kHz(250nWb/m -24dB). Use this tape together with a filter.

7. Blank tape TAPE : AC-225, TAPE : AC-514

8. Torque gauge : For play and back tension Forward ; TW2111A, Reverse ; TW2121A Fast Forward and Rewind ; TW2231A

9. Test disc : CTS-1000(12cm),GRG-1211(8cm)

10. Jitter meter

Measurement conditions

Power supply voltage AC110/127/220/230-240V(50Hz)

Measurement output terminal : Speaker out :TP101(Mesuring for TUNER/DECK/CD) :Dummy load 6ohm

Radio input signal

AM modulation frequency : 400Hz Modulation factor : 30% FM modulation frequency : 400Hz Frequency displacement : 22.5kHz

Frequency Range

AM 531kHz~1710kHz FM 87.5MHz~108MHz

Standard measurement positions of volume and switch

Power : Standby (Light STANDBY Indicator) S,A,BASS : OFF Sound mode : OFF Main VOL. : 0 Minimum Travers mecha set position : Disc 1 Mic MIX VOL : MAX ECHO : OFF

Precautions for measurement

1. Apply 30pF and 33kohm to the IF sweeper output side and 0.082 F and 100kohm in series to the sweeper input side.

2. The IF sweeper output level should be made as low as possible within the adjustable range.

3. Since the IF sweeper is a fixed device, there is no need to adjust this sweeper.

4. Since a ceramic oscillator is used, there is no need to perform any MPX adjustment.

5. Since a fixed coil is used, there is no need to adjust the FM tracking.

6. The input and output earth systems are separated. In case of simultaneously measuring the voltage in both of the input and output systems with an electronic voltmeter for two channels, therefore, the earth should be connected particularly.

7. In the case of BTL connection amplifier, the minus terminal of speaker is not for earthing. Therefore, be sure not to connect any other earth terminal to this terminal. This system is of an OTL system.

MX-J570V/MX-J680V

1-29

MX-J570V/MX-J680V

Arrangement of adjusting positions

Cassette mechanism section (Mechanism A section)

Head azimuth

adjusting screw

(Forward side)

Playback

head

Head azimuth

adjusting screw

(Reverse side)

Cassette mechanism section (Back side)

Head azimuth

adjusting screw

(Forward side)

Playback,recording and eraser

heads or playback head

Head azimuth

adjusting screw

(Reverse side)

Cassette mechanism unit section

Tape speed ADJ

Bias ADJ L

Bias ADJ R

1-30

+ 82 hidden pages

JVC MXJ-570-V, MXJ-680-V Service manual

Specifications and Main Features

Frequently Asked Questions

User Manual