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

MX-G68V/MX-G65V

SERVICE MANUAL

COMPACT COMPONENT SYSTEM

MX-G68V MX-G65V

	Area Suffix
US	Singapore
UX	Saudi Arabia

					DISC CHANGE
							VIDEO CD
			PLAY & EXCHANGE			CD-R/RW PLAYBACK
						SOUND
						MODE
					VIDEO CD
						SUBWOOFER
						LEVEL
					PRESET
						NEXT
					PREV
	COMPACT COMPONENT SYSTEM MX-G65V
				SET
				CANCEL
				/DEMO
PHONES
			TUNING
	CLOCK	DISPLAY	SELECT
	/ TIMER		REPEAT PROGRAM RANDOM
PBC	RETURN	VCD NUMBER	REC START CD	TAPE A	TAPE B
			/STOP REC START DUBBING
+							PlayBack
							Control
	EJECT					EJECT
–
	A PLAY		FULL - LOGIC CONTROL	CD SYNCHRO RECORDING		REC/PLAY B
SP-MXG65V		CA-MXG65V				SP-MXG65V
Model						Color
CA-MXG68V			Shanpagne-gold
CA-MXG65V			Silver
Contents
Safety precautions	1-2				Flow of functional operation
Preventing static electricity	1-3					until TOC read	1-23
Important for laser products	1-4				Maintenance of laser pickup		1-24
Disassembly method	1-5				Replacement of laser pickup		1-24
Wiring connection	1-18				Troubleshooting		1-25
Adjustment method	1-19				Description of major ICs		1-33~52

COPYRIGHT 2001 VICTOR COMPANY OF JAPAN, LTD.

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.

AC VOLTMETER

Measure the AC voltage across the resistor with

the AC

(Having 1000

voltmeter.

ohms/volts,

Move the resistor connection to each exposed metal part,

or more sensitivity)

particularly any exposed metal part having a return

path to

0.15 F AC TYPE

the chassis, and measure the AC voltage across the resistor.

Now, reverse the plug in the AC outlet and repeat each

Place this

measurement. Voltage measured any must not exceed 0.75 V

probe on

each exposed

AC (r.m.s.). This corresponds to 0.5 mA AC (r.m.s.).

1500

10W

metal part.

Good earth ground

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

CD holder mechanism

Fig.1

Card wire

Pickup unit connector

Fig.2

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.

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.

Position of labels

CLASS 1
LASER PRODUCT	WARNING LABEL

1-4

					MX-G68V/MX-G65V
Disassembly method				A	Metal cover
<Main body>
	Removing the metal cover	A					A
	(See Fig.1 and 2)

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

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

3.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.

Fig.1

Metal cover B

	Removing the CD changer unit
	(See Fig.3 to 6)	B		Fig.2
	Prior to performing the following procedure, remove
	the metal cover.

1.Disconnect the card wire which is attached with adhesive to the left side of the CD changer unit.

2.Disconnect the harness from connector CW1 and CW7 on the back of the video CD board.

3.Disconnect the harness from connector RCW6 on the main board.

4.Disconnect the card wire from connector UCW3 on the FL dispaly & system control board.

5.Remove the two screws C attaching the CD changer unit on the rear panel.

6.Remove the two screws D attaching the CD changer unit on the side body.

7.Draw the CD changer unit upward from behind while pulling the rear panel outward.

CD changer unit	Rear panel
	CW1
CW7	Video CD
	board

Front panel	(Bottom side)
assembly

Fig.3

1-5

MX-G68V/MX-G65V

C

RCW6

UCW3

	Front panel
	assembly
	FLdispaly & system			Rear panel
	control board	Fig.4
				Fig.5
			Adhesive card wire strap
		CD changer unit		CD changer unit

D D

Rear panel	Rear panel

Fig.6a

Fig.6b

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.

1.Disconnect the card wire from connector FCW3 and the harness from connector JCW1, JCW2 ECW1 and HCW3 on the inner side of the main board in the body.

2.Remove the two screws E attaching the front panel assembly on both sides of the body.

3.Remove the screw F attaching the earth terminal extending from the cassette mechanism assembly.

4.Remove the screw G attaching the front panel assembly and main board.

5.Remove the screw H attaching the front panel assembly on the bottom of the body.

6.Release the two joints a on both sides and two joints b on the bottom of the body using a screwdriver.

1-6

Front panel assembly

FCW3	Main board

JCW2 ECW1

JCW1

Joint a

E

HCW3

Earth wire F

Fig.7

Front panel assembly

Joint b

Main board

G	Bottom side

Joint c

E

Fig.8

MX-G68V/MX-G65V

H

Joint b

	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.
1. Remove the four screws I		attaching the heat sink	I
	cover to the rear panel on the back of the body.
2. Remove the four screws J attaching the heat sink &
	amplifier board to the rear panel on the back of the
	body.		Heat sink
			cover

3.Remove the two screws K attaching the speaker terminal to the rear panel on the back of the body.

4.	Disconnect the card wire from connector ACW1 and	I
	the harness from connector ACW2 on the amplifier
	board.
5.	After moving the heat sink upward, remove the	Rear panel
	claws. Then pull out the heat sink & amplifier board .

Fig.9

Fig.10

Tuner terminal

J

L

Rear panel

Heat sink

K

ACW2				J
			Amplifier			Speaker terminal
ACW1
			board			Fig.11
			Fig.12

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.

1.Disconnect the card wire from connector CON01 on the tuner board.

2.Remove the two screws L attaching the tuner board.

CON01

Main board

Rear

panel

Tuner board

Fig.13

	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.

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

Rear panel

N'

M

N

Fig.14

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.

1.Disconnect the card wire from connector FCW3 and the harness from connector JCW1, JCW2, ECW1 and HCW3 on the main board.

FCW3	ECW1	Main board

JCW1

JCW2 HCW3

O

2. Disconnect the harness from connector PCW1 on the power transformer board.

3.Remove the screw G attaching the main board holder. (See Fig.8)

4.Remove the two screws O attaching the heat sink and bottom chassis.

Transformer board PCW1

Fig.15

1-8

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 .

1.Remove the four screws P attaching the power ICs to the heat sink.

2.Unsolder the power ICs solder point.

MX-G68V/MX-G65V

Heat sink

P

Fig.16

Power ICs solder point

Amplifier board

Heat sink

Fig.17

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.

1.Disconnect the power cord from connector RCW2 of the power transformer board.

2.Disconnect the harness from connector PCW1 of the power transformer board.

3.Remove the four screws Q attaching the power transformer.

RCW2

Power transformer

PCW1

Q	Q		Power		cord

Fig.18

1-9

MX-G68V/MX-G65V

<Front panel assembly>

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)

1.Disconnect the card wire from connector UCW1 of the power switch board.

2.Remove the five screws R attaching the power switch board and release the tab c outward.

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

1.Disconnect the card wire from the connectors UCW3, UCW5,UCW6 and UJW5 on the FL display & system control board.

2.Remove the five screws S attaching the FL display & system board.

3.Disconnect the card wire from the connector UCW2 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.

1. You can pull out the headphone board.

Power switch board	UCW1
	R
	Tab c
	S
UCW2	FLdiplay & system
UCW3	control board
UJW5	S
S	UCW5
	UCW6
	Fig.19
Front board
	T
T	Headphone
	board
Tab d
T	T

Mic board

U

Card wire f

Cassette mechanism assembly

Tab e

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.

1.Pull out the volume knob, subwoofer level knob and sound mode knob from front side.

2.Remove the eleven screws T attaching the front board and release the two tabs d outward.

3.Release the two tabs e outward and remove the MIC board.

	Removing	the cassette mechanism
	assembly	(See Fig.20)

1.Disconnect the card wire f from the mechanism board on the cassette mechanism assembly.

2.Remove the six screws U attaching the cassette mechanism assembly.

1-10

SOUND MODE knob

SUBWOOFER

LEVEL knob

VOLUME knob

Fig.21

<CD changer unit>

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

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

1.Disconnect the card wire from connector SW1 of the video CD board.

2.Turn the black loading pulley gear on the under side of the CD changer unit in the direction of the arrow and draw the CD tray toward the front until it stops.

3.Disconnect the card wire from connector CW6 of the Video CD board on the upper side of the CD changer unit.

4.Push down the two tray stoppers marked a and pull out the CD tray.

Loading pulley gear

Video CD board SW1

Fig.1

CD tray

Fig.2

MX-G68V/MX-G65V

CD tray

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

1.Align the gear-cam with the gear-tray as shown fig.4, then mount the CD tray.

2.When assembling the CD tray, take extreme care not engage with gear-synchro.

Gear-cam

Gear-tray

CD tray

a

(Tray stopper)

Video CD board CW6

Fig.3

	Gear-convert		Gear-cam
			timing point
			Gear-tray
	Gear-convert	Gear-tray	CD tray
			Fig.5
		Fig.4

a (Tray stopper)

Gear-synchro

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.

1.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.

2.Disconnect the harness from connector CW1 on the sensor board and release the harness from the two hooks c. Remove the sensor board.

3.Remove the screw B attaching the turn table. Detach the turn table from the tray.

4.Pull outward the tab marked d attaching the turn table motor assembly on the upper side of the tray and detach the turn table motor assembly from the tray.

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

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

1.Disconnect the harness from connector on the CD 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.

2.Detach the belt from the pulley on the upper side of the CD changer unit (Do not stain the belt with grease).

3.Disconnect the card wire from the connector SW1 on 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.

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

A

Tab b

CW1

c

Tab b

Sensor board

Fig.6

Turn table

B

Tray

Fig.7

Turn table motor assembly

d

Fig.8

Motor

Belt

Fig.9 CD changer unit

D

SW1

MX-G68V/MX-G65V

Video CD board

Tabs f

Soldered points

Tabs f

Tab e

Motor board connector

Fig.10

Removing the CD mechanism holder assembly (mechanism included)

(See Fig.11 to 13)

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

2.Remove the screw E attaching the shaft on the right side of the CD mechanism holder assembly.

3.Pull outward the stopper fixing the shaft on the left side and remove the CD mechanism holder assembly from behind in the direction of the arrow.

4.Pull out the CD mechanism holder assembly.

SW1	CD mechanism
	holder assembly

Motor board

Pickup unit

connector

Stopper Fig.11 E

	CD changer unit
	CD mechanism holder assembly
Fig.12	Fig.13

1-13

MX-G68V/MX-G65V

<Cassette mechanism section>

Prior to performing the following procedure, removing the cassette mechanism.

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

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

2.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)

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

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

P.B. head

P.B. head assembly

Fig.1

D C

P.B. head

D C B

Cassette mechanism

R/P head

R/P head assembly

B A

R/P head

A

Fig.3

Fig.2

1-14

MX-G68V/MX-G65V

Removing the pinch roller unit.

(Fig. 4)

Prior to performing the following procedure, removing the cassette mechanism.

1.Remove the two screws E attaching the pinch roller unit.

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.

E

Slide spring

Pinch roller cap

	Pinch roller
Cassette mechanism	Slide spring

R/P Head
Pinch roller unit
Fig.4	Stopper

1-15

MX-G68V/MX-G65V

Removing the flywheel. (Fig.5 to 7)

Cassette mechanism

Prior to performing the following procedure, removing the cassette mechanism.

1.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.

a

	Removing the motor. (Fig.7 to 9)	Capstan shaft b	Capstan shaft
	Prior to performing the following procedure,	Fig.5
	removing the cassette mechanism.	b	a
	1. Unsolder the solder point on the motor terminal.
		Washer

2. Remove the capstan belt from the motor pulley.

3. Remove the two screws F attaching the	Drive belt	Drive belt
motor bracket.

4. Remove the two screws G attaching the motor.

Capstan belt (Flat)

Fig.6

Solder point

Drive belt	Drive belt
Capstan belt (Flat)	Capstan belt (Flat)

				Fig.7
	Motor bracket			F	Motor bracket
		Motor
	G	G
	Fig.9				Cassette mechanism
	Capstan belt (Flat)	Capstan belt (Flat)	Fig.8	F

1-16

< Speaker section >

	Removing the side panel	(See Fig. 1)

1.Remove the five screws A and B attaching the side panel, then remove the side panel.

A

C

Removing the side speaker

(See Fig. 2 and 3)

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

1.	Remove the fore screws C attaching the side
	speaker.
2.	Pull out the side speaker and remove the speaker	C
	cord from the speaker terminal.

Side speaker

MX-G68V/MX-G65V

B

Side panel

B

Fig.1

Side speaker

Front panel

Fig.2

Speaker terminal

Fig.3

1-17

18-1

3809-001237

3809-001222

						Tuner board
-AH39					CON1					Voice board
								0	9	CW301	CW302
00246A										3710-000209
				Main board					3708-000122
							3711-000907		FCW1		9
3708-000258		FCW3		3711-003107				RCW6			0
									OCW		2
			JCW2			JCW1			3711-000907
3711-003111								3711-001557
0				JCW3				KCW1	KCW2
	9								FCW2
							3708-001094
							HCW3
						ECW1		3711-001062
				3711-001062
	0
							RW1		RW2
9	2								VCW1
							9		9
									0
	0						0		9	0
								9
			-AH39					0
				HCW2
			00022A				9	AH39-00247A
							0
				H.phone J.board
		0	9		0		Cassette mechanism
			9	0		9
			8	8	2
	-AH39							2			0
	00202A								0
						0		9	9	0	9

9

2 0

2	8

8

3809-001228		AH39-00248A MCW3		001185-3809			connectionWiring	G65V-G68V/MX-MX
3809-000492						Amp. board
	CD key switch board				ACW2	3711-001167
UCW1			3809-001224
					ACW1
		UCW7			3708-001094
	3708-000181
			0		9
Front key switch board		MCW1	9			0
			MIC board
	MCW2
			AH39-00254A
			AH39-00244A
Front / Display board		UCW2 3708-000178			0 9	0

3708-001212

		UCW3	3711-000588
	3708-000451		PCW1
3708-000492	UCW4		RFS5
			RFS6
UCW5 3708-001488
			RFS7
	UCW6		RFS8

3711-000190

RCW2

RFS3

RFS4

RFS2

Power transformer

CD tray

3809-001185

Roller board

3809-001233

AH39-00097A

AH39-00347A
0	9	0		0	9
		9			2	CD pick up unit board
								Color
						Motor board
CW7		CW2	CW5	CW1		0	1 2 3 4 5 6 7 8 9 0	codes
Video CD board			3708-001027		OPTICAL
						9		are
CW6
						CD Pick up board		.belowshown
			CW1
							Brown Red Orange Yellow Green Blue Violet Gray White Black
AH39-00096B	9
0

MX-G68V/MX-G65V

Adjustment method

1. Tuner

* Adjustment Location of Tuner PCB

AM(MW) OSC

AM(MW) RF

LW OSC

AM(MW) RF

ITEAM

Adjustment

Adjustment

Adjustment

Adjustment

(Except for J/C)

Received FREQ.

531~1602 KHz

594 KHz

146~290 KHz

150 KHz

(9kHz step)

530~1600 KHz

(10kHz step)

Adjustment

MO

MA

LO

LA

point

Output

1~7.0 0.5V

Maximum

2~7.0 0.5 V

Maximum

Output(Fig1-4)

Output(Fig1-4)

MAIN

VT

GND

TESTER

PCB

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)

Output	FM
	Antenna	SET
GND
	Terminal
FM S.S.G		Input	Oscilloscope
	Speaker
	Terminal	output	Input
		Distortion Meter

Figure1-1 IF CENTER and THD Adjustment

FM Search Level Adjustment

SSG FREQ.	98 MHz
Adjustment	BEACON
point
	SENSITIVITY
(SVR1)	SEMI-VR(20K	)
Output	28 dB( 2dB)
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.	450 kHz
Frequency	531 kHz
	(9kHz step)
	530 kHz
	(10kHz step)
Adjustment	AM IF
point

Maximum output (Figure 1-3)

	28 dB	FM Antenna
		SET
FM S.S.G	GND	FM IN

20 k

Figure1-2 FM Auto Search Level Adjustment

	60cm
		AM IF
	OUTPUT	AM ANT
		IN
	AM SSG	Speaker Terminal
	450KHZ
	INPUT	OUTPUT
	VTVM	Oscilloscope

Figure1-3 AM I.F Adjustment

1-20

2 Cassette Deck

To adjust tape speed

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.

MX-G68V/MX-G65V

Cassette Deck

Frequency Counter

SPK OUT

output

Figure 1-5

Step

Item

Pre-Setup

Pre-Setup

To Adjust

Standard

Remark

Condition

1)

Deck 1:VT-712

OUT

NOR

2)

Press PLAY

1%

1

(connected

Turn VSR1 to

SPEED

SW button

3KHz

range

to the frequency

left and right

Control

3)

Deck 2:Same

(FRONT PCB)

counter)

as above

	Recording /Play head		Oscilloscope
	Cassette Deck	VTVM
	SPK OUT
	(GND)	In Out
	AZIMUTH control screw	Figure 1-7
	Figure 1-6

SET		VTVM	Oscilloscope
(MAIN PCB)
Audio OSC.
LINE OUT
IN	TP
AUX IN	JCW3	IN OUT

Figure 1-8

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

Pre-Setup

To Adjust

Standard

Remark

Condition

After putting VT -

- Turn the control

SPK OUT

703 into Deck A

After

screw to as shown

Max output

(VTVM is

- Press FWD PLAY

adjustment

in Figure 1-6.

and same phase

AZIMUTH

1

connected to

button.

(both channels)

secure it with

the scope)

REGION

LOCK.

2. Adjust Deck B Play Level/REC BIAS

Step

Item

Pre-Setup

Pre-Setup

To Adjust

Standard

Remark

Condition

After putting VT-703

- Turn the control

SPK OUT

into Deck B

After

1

screw to as shown

Max output

(VTVM is

adjustment

AZIMUTH

1)Press FWD PLAY

in Figure 1-6.

and same phase

connected to

secure it with

button.

(both channels)

REGION

the scope)

LOCK.

After putting AC-225

Turn JSR2L,JSR2R

Recording

into Deck B

7mV( 0.5mV)

to the right and left

Bias

Fig 1-8

2

1)Press REC PLAY

Voltage

button.

2)MAIN PCB JCW3,

connectted to VTVM

1-22

MX-G68V/MX-G65V

Flow of functional operation until TOC read

Play Key

Check Point

Power ON

RESET a CD LSI

Confirm that the voltage at the pin17

of KB9226(IC101) is "L"

"H".

Confirm that the voltage at the pin33

LIMIT SW ON

of KB9226(IC101) is "H"

"L"

"H".

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

		Tracking error waveform at TOC reading
	Pin 34 of	Approx.3.7sec
	KB9226
	(IC101)
	Approx
	0.4V
	2.50V
		Disc states
		to rotate

	Disc is rotated					Confirm that the signal from pin24
						of KB9226(IC101) is 3.5V as a
						accelerated pulse during
						approx.1.96s.
	Automatic adjusting of					Confirm the waveform of
	TE balance
						the Tracking error signal
						at the pin 34 of KB9226(IC101).
	Automatic adjusting of
	TE gain

TOC reading

Confirm the eye-pattern

at the pin2 of KB9226(IC101).

Play a disc

1-23

MX-G68V/MX-G65V

Maintenance of laser pickup Replacement 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	NO
	RFOUT under
				Replace it.
	1.1V 0.2Vp-p?

YES

O.K

(3) Semi-fixed resistor on the APC PC board

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.

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.

1-24

MX-G68V/MX-G65V

Troubleshooting

1.Amplifier

Power Malfunction : COMMON

1-25

MX-G68V/MX-G65V

<No Output>

1-26

MX-G68V/MX-G65V

2. Tuner malfunction (FM/AM)

1-27