Jvc MX-G68-V, MX-G65-V Service Manual

MX-G68V/MX-G65V

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SERVICE MANUAL

COMPACT COMPONENT SYSTEM

MX-G68V

STANDBY/ON

456

SLEEP

FM/AM

SELECT

PREV.

RM–SMXG65VU REMOTE CONTROL

MX-G65V

STANDBY

STANDBY/ON

COMPACT

DIGITAL VIDEO

COMPACT COMPONENT SYSTEM

SOUND

SUBWOOFER

MODE

LEVEL

ON SCREEN

V.INTRO

HIGHLIGHT

SLOW

AUX

FM MODE/

KEY CONTROL

STILL

+10

RETURN

KARAOKE

ECHO

FADE

TAPE

TAPE A/B

MUTING

DISC SKIP

VOLUME

–

SP-MXG65V

PHONES

SELECT

CLOCK

DISPLAY

TIMER

REPEAT PROGRAM

REC START

RETURNPBC

VCD NUMBER

/STOPCDREC START

EJECT

FULL - LOGIC CONTROL

PLAY

CA-MXG65V

DISC CHANGE

PLAY & EXCHANGE

MX-G65V

TUNING

RANDOM

DUBBING

VIDEO CD

SET

CANCEL /DEMO

TAPE A

TAPE B

CD SYNCHRO RECORDING

CD-R/RW PLAYBACK

SOUND

MODE

SUBWOOFER

LEVEL

PRESET

EJECT

REC/PLAY

SP-MXG65V

US Singapore UX

Saudi Arabia

VIDEO CD

Area Suffix

Model CA-MXG68V CA-MXG65V

Contents

Safety precautions Preventing static electricity Important for laser products Disassembly method Wiring connection Adjustment method

Color

Shanpagne-gold Silver

1-2 1-3 1-4 1-5 1-18 1-19

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

1-23 1-24 1-24 1-25 1-33~52

  No.20995

Jul. 2001

MX-G68V/MX-G65V

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 property damage resulting therefrom.

3. Many electrical and mechanical parts 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 original lead routing and dress should be observed, and it should be confirmed that they have been returned to normal, after re-assembling.

5. Leakage current 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 each exposed metal part, particularly any exposed metal part having a return path to the chassis, and measure 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.

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.

In regard with component parts appearing on the silk-screen printed side (parts side) of the PWB diagrams, the parts that are printed over with black such as the resistor ( ), diode ( ) and ICP ( ) or identified by the " " mark nearby are critical for safety. When replacing them, be sure to use the parts of the same type and rating as specified by the manufacturer. (Except the J&C version)

1-2

MX-G68V/MX-G65V

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 CD mechanism assembly is decomposed

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

1. Remove the CD changer unit.

2. Remove the CD holder mechanism.

3. Solder is put up before the card wire is removed from the pickup unit connector on the CD mechanism assembly. (When the card wire is removed without putting up solder, the CD pick-up assembly might destroy.)

4. Please remove solder after connecting the card wire with the pickup unit connector when you install picking up in the substrate.

Card wire

Pickup unit connector

Soldering

CD changer unit

Fig.1

Card wire

Pickup unit connector

Fig.2

CD holder mechanism

1-3

MX-G68V/MX-G65V

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 laserradiation and is equipped with safety switches whichprevent 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.

Position of labels

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.

CLASS 1 LASER PRODUCT

WARNING LABEL

1-4

MX-G68V/MX-G65V

Disassembly method

Removing the metal cover

(See Fig.1 and 2)

Remove the three screws A attaching the metal

1. cover on the back of the body.

Remove the six screws B attaching the metal cover

2. on both sides of the body.

Remove the metal cover from the body by lifting the

3. rear part of the cover.

ATTENTION:

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

Fig.1

Metal cover

Removing the CD changer unit

(See Fig.3 to 6)

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

Disconnect the card wire which is attached with

1. adhesive to the left side of the CD changer unit.

Disconnect the harness from connector CW1 and

2. CW7 on the back of the video CD board.

Disconnect the harness from connector RCW6 on

3. the main board.

Disconnect the card wire from connector UCW3 on

4. the FL dispaly & system control board.

Remove the two screws C attaching the CD changer

5. unit on the rear panel.

Remove the two screws D attaching the CD changer

6. unit on the side body.

Draw the CD changer unit upward from behind while

7. pulling the rear panel outward.

CD changer unit

Front panel

assembly

Fig.2

CW1

CW7

(Bottom side)(Bottom side)

Fig.3

Rear panel

Video CD

board

1-5

MX-G68V/MX-G65V

UCW3

Front panel

assembly

FLdispaly & system

control board

Rear panel

Fig.4

CD changer unit

RCW6

Adhesive card wire strap

Rear panel

Fig.5

CD changer unit

Rear panel

1-6

Fig.6a

Front panel assembly

Removing the front panel assembly

(See Fig.7 to 9 )

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

Disconnect the card wire from connector FCW3 and

1. the harness from connector JCW1, JCW2 ECW1 and HCW3 on the inner side of the main board in the body.

Remove the two screws E attaching the front panel

2. assembly on both sides of the body.

Remove the screw F attaching the earth terminal

3. extending from the cassette mechanism assembly.

Remove the screw G attaching the front panel

4. assembly and main board.

Remove the screw H attaching the front panel

5. assembly on the bottom of the body.

Release the two joints a on both sides and two joints

6. b on the bottom of the body using a screwdriver.

Front panel assembly

FCW3

Joint a

Earth wire

Fig.6b

JCW2

Fig.7

Main board

ECW1

JCW1

HCW3

MX-G68V/MX-G65V

Front panel assembly

Main board

Fig.8

Joint c

Removing the heat sink & amplifier

board (See Fig.10 to 12)

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

Remove the four screws I attaching the heat sink

1. cover to the rear panel on the back of the body.

Bottom side

Joint b

Fig.9

Joint b

Remove the four screws J attaching the heat sink &

2. amplifier board to the rear panel on the back of the body.

Remove the two screws K attaching the speaker

3. terminal to the rear panel on the back of the body.

Disconnect the card wire from connector ACW1 and

4. the harness from connector ACW2 on the amplifier board.

After moving the heat sink upward, remove the

5. claws. Then pull out the heat sink & amplifier board .

Rear panel

Heat sink

cover

Rear panel

Heat sink

Fig.10

Tuner terminal

ACW2

ACW1

Fig.12

Amplifier board

Speaker terminal

Fig.11

1-7

MX-G68V/MX-G65V

Removing the tuner board

(See Fig.11 and 13)

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

Disconnect the card wire from connector CON01 on

1. the tuner board.

Rear panel

CON01

Remove the two screws L attaching the tuner board.

Removing the rear panel (See Fig.14)

Prior to performing the following procedure, remove the metal cover, CD changer unit, heat sink & amplifier board and tuner board.

Remove the one screw M, three screws N and three screws N' attaching the rear panel.

Main board

Tuner board

Fig.13

Rear panel

Removing the main Board

(See Fig. 15)

Prior to performing the following procedure, remove the metal cover, CD changer unit, heat sink & amplifier board, tuner board and rear cover.

Disconnect the card wire from connector FCW3 and

1. the harness from connector JCW1, JCW2, ECW1 and HCW3 on the main board.

Disconnect the harness from connector PCW1 on

2. the power transformer board.

Remove the screw G attaching the main board

3. holder. (See Fig.8)

Remove the two screws O attaching the heat sink

4. and bottom chassis.

FCW3

Transformer board

JCW2

PCW1

Fig.14

ECW1

JCW1

Fig.15

Main board

HCW3

1-8

MX-G68V/MX-G65V

Removing the power ICs (See Fig.16 and 17)

Prior to performing the following procedure, remove the metal cover, CD changer unit, heat sink & amplifier board .

Remove the four screws P attaching the power ICs

1. to the heat sink.

Unsolder the power ICs solder point.

Heat sink

Fig.16

Power ICs solder point

Amplifier board

Heat sink

Removing the power transformer

(See Fig.18)

Prior to performing the following procedure, remove the metal cover, CD changer unit, heat sink & amplifier board, tuner board and rear cover.

Disconnect the power cord from connector RCW2 of

1. the power transformer board.

Disconnect the harness from connector PCW1 of the

2. power transformer board.

Remove the four screws Q attaching the power

3. transformer.

Power transformer

PCW1

Fig.17

Fig.18

RCW2

Power cord

1-9

MX-G68V/MX-G65V

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

Removing the power switch board

(See Fig.19)

Disconnect the card wire from connector UCW1 of

1. the power switch board.

Remove the five screws R attaching the power

2. switch board and release the tab c outward.

Removing the FL display & system control board (See Fig.19)

Disconnect the card wire from the connectors

1. UCW3, UCW5,UCW6 and UJW5 on the FL display & system control board.

Remove the five screws S attaching the FL display &

2. system board.

Disconnect the card wire from the connector UCW2

3. on the FL display & system control board.

Removing the headphone board

(See Fig.20)

Prior to performing the following procedure remove the FL display & system control board.

You can pull out the headphone board.

Power switch board

UCW2

UCW3

UJW5

Front board

Mic board

Tab e

Tab d

UCW1

Tab c

FLdiplay & system

control board

UCW5

UCW6

Fig.19

Headphone board

Card wire f

Cassette mechanism assembly

Fig.20

Removing the front board / MIC board

(See Fig. 20 and 21)

Prior to performing the following procedure, remove the FL display & system control board.

Pull out the volume knob, subwoofer level knob and

1. sound mode knob from front side.

Remove the eleven screws T attaching the front

2. board and release the two tabs d outward.

Release the two tabs e outward and remove the MIC

3. board.

Removing the cassette mechanism assembly (See Fig.20)

Disconnect the card wire f from the mechanism

board on the cassette mechanism assembly.

Remove the six screws U attaching the cassette

mechanism assembly.

1-10

SOUND MODE knob

SUBWOOFER LEVEL knob

VOLUME knob

Fig.21

MX-G68V/MX-G65V

Prior to performing the following procedure, remove the CD changer unit.

Removing the CD tray (See Fig.1 to 3)

Disconnect the card wire from connector SW1 of the

1. video CD board.

Turn the black loading pulley gear on the under side

2. of the CD changer unit in the direction of the arrow and draw the CD tray toward the front until it stops.

Disconnect the card wire from connector CW6 of the

3. Video CD board on the upper side of the CD changer unit.

Push down the two tray stoppers marked a and pull

4. out the CD tray.

CD tray

Loading pulley

gear

Video CD

board

SW1

Fig.1

CD tray

Reinstall the CD tray (See Fig.4 and 5)

Align the gear-cam with the gear-tray as shown fig.4,

1. then mount the CD tray.

When assembling the CD tray, take extreme care not

2. engage with gear-synchro.

Gear-cam

Gear-tray

Gear-convert

Gear-cam

timing point

Fig.2

a (Tray stopper)

CD tray

(Tray stopper)

Video CD board

CW6

Fig.3

Gear-synchro

Gear-convert

Gear-tray

CD tray

Fig.4 Fig.5

1-11

MX-G68V/MX-G65V

Removing the sensor board / the turn table motor assembly (See Fig.6 to 8)

Prior to performing the following procedure, remove the CD tray.

Remove the screw A attaching the sensor board and

release the two tabs b attaching the sensor board on the under side of the CD tray.

Disconnect the harness from connector CW1 on the

2. sensor board and release the harness from the two hooks c. Remove the sensor board.

Remove the screw B attaching the turn table. Detach

3. the turn table from the tray.

Pull outward the tab marked d attaching the turn

4. table motor assembly on the upper side of the tray and detach the turn table motor assembly from the tray.

Tray

Tab b

CW1

Tab b

Sensor board

Fig.6

Turn table

Removing the belt, the Video CD board (See Fig.9 and 10)

Prior to performing the following procedure, remove the CD tray.

Disconnect the harness from connector on the CD

1. mechanism board in the CD mechanism assembly on the under side of the CD changer unit. Disconnect the card wire from the pickup unit connector.

Detach the belt from the pulley on the upper side of

2. the CD changer unit (Do not stain the belt with grease).

Disconnect the card wire from the connector SW1 on

3. the Video CD board.

Remove the three screws D attaching the video CD board. First release the three tabs f and tabs e attaching the video CD board motor to raise the video CD board slightly, then release the video CD board.

Fig.7

Turn table motor assembly

Fig.8

Motor

Belt

If the tabs e and f are hard to release, it is recommendable to unsolder the two soldered points on the motor terminal of the video CD board.

1-12

Fig.9

CD changer unit

MX-G68V/MX-G65V

SW1

Video CD board

Motor board connector

Fig.10

Removing the CD mechanism holder assembly (mechanism included)

(See Fig.11 to 13)

SW1

Tabs f

Soldered points

Tabs f

Tab e

CD mechanism

holder assembly

Disconnect the card wire from pickup unit connector

1. on the motor board in the CD mechanism holder assembly on the under side of the CD changer unit.

Remove the screw E attaching the shaft on the right

2. side of the CD mechanism holder assembly.

Pull outward the stopper fixing the shaft on the left

3. side and remove the CD mechanism holder assembly from behind in the direction of the arrow .

Pull out the CD mechanism holder assembly.

CD changer unit

Motor board

Stopper

Fig.11

Pickup unit connector

Fig.12

CD mechanism holder assembly

Fig.13

1-13

MX-G68V/MX-G65V

Prior to performing the following procedure,

removing the cassette mechanism.

Removing the R/P head. (Fig.1 to 3)

Remove the screw A attaching the R/P head right side.

Remove the screw B attaching R/P head left side. (Screw B : Head azimuth adjusting screw.)

Removing the P.B. head. (Fig.1 to 3)

Removing the screw C attaching the P.B. head right side.

Removing the screw D attaching the P.B. head left side. (Screw D : Head azimuth adjusting screw.)

P.B. head

P.B. head assembly

Cassette mechanism

R/P head

Fig.1

P.B. head

R/P head assembly

R/P head

1-14

Fig.3

Fig.2

Removing the pinch roller unit. (Fig. 4)

Prior to performing the following procedure,

removing the cassette mechanism.

Remove the two screws E attaching the p

Attention:

The pinch roller cap is forcefully fitted to the shaft of the pinch roller unit. If the pinch roller cap is taken out by force, the shaft will be broken. When replacing the pinch roller, it should be changed as a pinch roller unit itself.

inch roller unit

MX-G68V/MX-G65V

Slide spring

Cassette mechanism

R/P Head

Pinch roller unit

Fig.4

Pinch roller cap

Pinch roller

Slide spring

Stopper

1-15

MX-G68V/MX-G65V

Removing the flywheel. (Fig.5 to 7)

Prior to performing the following procedure,

removing the cassette mechanism.

Remove the cut washers at a and b from the capstan shaft. Then remove the flywheel. When reassembling the flywheel, be sure to use new cut washers as they cannot be reused.

Removing the motor. (Fig.7 to 9)

Prior to performing the following procedure,

removing the cassette mechanism.

Unsolder the solder point on the motor terminal.

Remove the capstan belt from the motor pulley.

Remove the two screws F attaching the motor bracket.

Remove the two screws G attaching the motor.

Drive belt

Capstan shaft

Capstan belt

Cassette mechanism

Fig.5

Washer

Capstan shaft

Drive belt

(Flat)

Motor bracket

Motor

Capstan belt

Drive belt

(Flat)

Fig.6

Capstan belt

Fig.7

Motor bracket

Solder point

Drive belt

(Flat)

Capstan belt

1-16

(Flat)

Fig.9

Capstan belt

(Flat)

Fig.8

Cassette mechanism

< Speaker section >

MX-G68V/MX-G65V

Removing the side panel (See Fig. 1)

Remove the five screws A and B attaching the side

1. panel, then remove the side panel.

Removing the side speaker

(See Fig. 2 and 3)

Side panel

Fig.1

Side speaker

Front panel

Prior to performing the following procedure, remove the side panel.

Remove the fore screws C attaching the side

1. speaker.

Pull out the side speaker and remove the speaker

2. cord from the speaker terminal.

Fig.2

Side speaker

Speaker terminal

Fig.3

1-17

MX-G68V/MX-G65V

Wiring connection

Amp. board

3711-001167

ACW2

ACW1

3708-001094

3809-001224

UCW7

CD key switch board

3809-000492

UCW1

3809-001228

3809-001185

MCW1

3708-000181

MIC board

Front key switch board

MCW3

AH39-00254A

AH39-00244A

AH39-00248A

MCW2

3711-000190

9 0

3711-000588

3708-000178

UCW2

UCW3

3708-001212

Front / Display board

RCW2

RFS4

RFS3

RFS5

RFS6

RFS7

PCW1

UCW4

3708-000451

UCW6

3708-001488

UCW5

3708-000492

RFS8

RFS2

Power transformer

CD tray

Roller board

3809-001233

3809-001185

AH39-00347A

AH39-00097A

Color codes are shown below. 1 Brown

2Red 3 Orange 4 Yellow 5 Green 6 Blue 7 Violet 8Gray 9 White 0Black

Motor board

CD Pick up board

CD pick up unit board

OPTICAL

CW1

CW5

3708-001027

CW2

CW7

CW6

Video CD board

CW1

9 0

AH39-00096B

1-18

3809-001237

3809-001222

Tuner board

CW302

Voice board

CW301

CON1

AH39-00246A

3710-000209

FCW1

3708-000122

RCW6

3711-000907

Main board

FCW3

3708-000258

OCW

KCW2

3711-000907

FCW2

3711-001557

KCW1

JCW1

3711-003107

JCW3

JCW2

3711-003111

RW2

3711-001062

3708-001094

HCW3

ECW1

3711-001062

VCW1

RW1

2 9

0 9

AH39-00022A

HCW2

AH39-00247A

H.phone J.board

Cassette mechanism

AH39-00202A

Adjustment method

1. Tuner

MX-G68V/MX-G65V

ITEAM

Received FREQ.

Adjustment point

Output

* Adjustment Location of Tuner PCB

AM(MW) OSC Adjustment

531~1602 KHz (9kHz step) 530~1600 KHz (10kHz step)

1~7.0 0.5V

MAIN PCB

AM(MW) RF Adjustment

594 KHz

Maximum Output(Fig1-4)

VT GND

LW OSC Adjustment

(Except for J/C)

146~290 KHz

2~7.0 0.5V

AM(MW) RF Adjustment

150 KHz

Maximum Output(Fig1-4)

TESTER

Fig 1-4 OSC Voltage

1-19

MX-G68V/MX-G65V

FM THD Adjustment

SSG FREQ.

98 MHz

Adjustment point

FM DETECTOR COIL

(FM DET) Output

60 dB

Minumum Distortion (0.4% below) (Figure 1-1)

FM Search Level Adjustment

SSG FREQ. Adjustment

point

(SVR1)

Output

BEACON SENSITIVITY SEMI-VR(20K )

28 dB(

98 MHz

2dB)

Output GND

FM S.S.G

FM Antenna Terminal

Speaker Terminal

SET

Input

output

Distortion Meter

Figure1-1 IF CENTER and THD Adjustment

FM Antenna

SET

FM IN

FM S.S.G

28 dB

GND

Oscilloscope

Input

Adjust SVR1 so that "TUNED" of FL T is lighted (Figure 1-2)

*Adjust FM S.S.G level to 28dB

AM(MW) I.F Adjustment

SSG FREQ. Frequency

450 kHz 531 kHz

(9kHz step) 530 kHz (10kHz step)

Adjustment point

AM IF

Maximum output (Figure 1-3)

Figure1-2 FM Auto Search Level Adjustment

60cm

OUTPUT

AM SSG 450KHZ

INPUT

AM ANT IN

Speaker Terminal

OUTPUT

VTVM Oscilloscope

Figure1-3 AM I.F Adjustment

20 k

AM IF

1-20

2 Cassette Deck

To adjust tape speed

MX-G68V/MX-G65V

Notes

1) Measuring tape: i) VT-712

(Tapes recorded with 3kHz)

ii) AC-225

2) Connect the cassette deck to the frequency counter

as in figure 1-5.

Step

Item

Pre-Setup Condition

Pre-Setup

1) Deck 1:VT-712

NOR SPEED Control

Recording /Play head

OUT (connected to the frequency counter)

2) Press PLAY SW button

3) Deck 2:Same as above

Cassette Deck

SPK OUT

To Adjust

Turn VSR1 to left and right (FRONT PCB)

Cassette Deck

SPK OUT

Figure 1-5

VTVM

Frequency Counter

Standard

3KHz

Oscilloscope

output

Remark

range

AZIMUTH control screw

Figure 1-6

Audio OSC.

SET (MAIN PCB)

AUX IN

LINE OUT

JCW3

Figure 1-8

VTVM

IN OUT

(GND)

In Out

Figure 1-7

Oscilloscope

1-21

MX-G68V/MX-G65V

To adjust plabyback level/REC

Notes

1) Before the actual adjustment, clean the play/recording head.

2) Measuring tape : i) VT-703 (10kHz AZIMUTH control)

ii) AC-225

3) The cassette deck is connections as shown in figure 1-7.

1. Adjust Deck A Play Level

Step

Item

Pre-Setup Condition

Pre-Setup

After putting VT-

AZIMUTH

SPK OUT (VTVM is connected to

703 into Deck A

- Press FWD PLAY button.

the scope)

2. Adjust Deck B Play Level/REC BIAS

Step

Item

AZIMUTH

Pre-Setup Condition

SPK OUT (VTVM is connected to the scope)

Pre-Setup

After putting VT-703 into Deck B

1)Press FWD PLAY button.

To Adjust

- Tu rn the control screw to as shown in Figure 1-6.

To Adjust

- Turn the control screw to as shown in Figure 1-6.

Standard

Max output and same phase (both channels)

Standard

Max output and same phase (both channels)

Remark

After adjustment secure it with REGION LOCK.

Remark

After adjustment secure it with REGION LOCK.

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Recording Bias Voltage

Fig 1-8

After putting AC-225

into Deck B

1)Press REC PLAY button.

2)MAIN PCB JCW3, connectted to VTVM

Turn JSR2L,JSR2R

to the right and left

7mV(

0.5

mV)

Flow of functional operation until TOC read

Power ON

Play Key

RESET a CD LSI

Confirm that the voltage at the pin17 of KB9226(IC101) is "L" "H".

MX-G68V/MX-G65V

Check Point

LIMIT SW ON

SET Default value of TE gain, TE balance

Automatic adjusting of

focus bias

Automatic adjusting of

FE offset

Automatic adjusting of

TE offset

LASER power ON

Detection of disk

Confirm that the voltage at the pin33 of KB9226(IC101) is "H" "L" "H".

Confirm that the voltage at the pin37 of KB9226(IC101) is 3.5V.

Tracking error waveform at TOC reading

Pin 34 of KB9226 (IC101)

Approx

0.4V

2.50V

Disc states to rotate

Approx.3.7sec

Disc is rotated

Automatic adjusting of

TE balance

Automatic adjusting of

TE gain

TOC reading

Play a disc

Confirm that the signal from pin24 of KB9226(IC101) is 3.5V as a accelerated pulse during approx.1.96s.

Confirm the waveform of the Tracking error signal at the pin 34 of KB9226(IC101).

Confirm the eye-pattern at the pin2 of KB9226(IC101).

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MX-G68V/MX-G65V

Maintenance of laser pickup

(1) Cleaning the pick up lens Before you replace the pick up, please try to clean the lens with a alcohol soaked cotton swab.

(2) Life of the laser diode When the life of the laser diode has expired, the following symptoms will appear.

1. The level of RF output (EFM output:ampli tude of eye pattern) will below.

Is the level of

RFOUT under

1.1V 0.2Vp-p?

YES

O.K

Replace it.

Replacement of laser pickup

Turn off the power switch and,disconnect the power cord from the ac outlet.

Replace the pickup with a normal one.(Refer to "Pickup Removal" on the previous page)

Plug the power cord in,and turn the power on. At this time,check that the laser emits for about 3seconds and the objective lens moves up and down. Note: Do not observe the laser beam directly.

Play a disc.

Check the eye-pattern at TP1.

Finish.

(3) Semi-fixed resistor on the APC PC board The semi-fixed resistor on the APC printed circuit board which is attached to the pickup is used to adjust the laser power. Since this adjustment should be performed to match the characteristics of the whole optical block, do not touch the semi-fixed resistor. If the laser power is lower than the specified value,the laser diode is almost worn out, and the laser pickup should be replaced. If the semi-fixed resistor is adjusted while the pickup is functioning normally,the laser pickup may be damaged due to excessive current.

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Troubleshooting

1.Amplifier

Power Malfunction : COMMON

MX-G68V/MX-G65V

1-25

MX-G68V/MX-G65V

1-26

2. Tuner malfunction (FM/AM)

MX-G68V/MX-G65V

1-27

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