JVC UX-G70 Service Manual

SERVICE MANUAL

COMPACT COMPONENT SYSTEM

MX-G70

J
C

MX-G70

Area Suffix

U.S.A.

Canada

Contents

Safety precautions
Important for laser products
Warnings and Cautions
Preventing static electricity
Importance administering
point on the safety
Disassembly method

STANDBY/ON

CD-R/RW PLAYBACK

STANDBY

CA-MXG70SP-MXG70

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

1-5
1-6

PLAY & EXCHANGE

MX-G70

SP-MXG70

Adjustment method

1-26
Flow of functional operation
until TOC read
Maintenance of laser pickup
Replacement of laser pickup
Description of major ICs

1-30

1-31

1-31

1-32

COPYRIGHT 2001 VICTOR COMPANY OF JAPAN, LTD.

No.20920

Mar. 2001

MX-G70

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.

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

Move the resistor connection to each exposed
metal part, particularly 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

0.15 F AC TYPE

1500 10W

Place this
probe on
each exposed
metal part.

exceed 0.75 V AC (r.m.s.). This corresponds to 0.5
mA AC (r.m.s.).

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.

1-2

Important for laser products

MX-G70

1.CLASS 1 LASER PRODUCT

2.DANGER : Invisible laser radiation when open and inter

lock failed or defeated. Avoid direct exposure to beam.

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

4.CAUTION : The compact disc player uses invisible laser

radiation and is equipped with safety switches which

prevent emission of radiation when the drawer is open and
the safety interlocks have failed or are defeated. It is
dangerous to defeat the safety switches.

Warnings and Cautions

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK,
DO NOT REMOVE COVER (OR BACK).
NO USER SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.

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.

The lightning flash with arrowhead symbol,
within an equilateral triangle is intended to
alert the user to the presence of uninsulated
"dangerous voltage" within the product's
enclosure that may be of sufficient
magnitude to constitute a risk of electric
shock to persons.

The exclamation point within an equilateral
triangle is intended to alert the user to the
presence of important operating and
maintenance (servicing) instructions in the
literature accompanying the appliance.

WARNING: TO REDUCE THE RISK OF FIRE
OR ELECTRIC SHOCK, DO NOT EXPOSE
THIS APPLIANCE TO RAIN OR MOISTURE.

For Canada/pour le Canada

CAUTION: TO PREVENT ELECTRIC SHOCK, MATCH WIDE

BLADE OF PLUG TO WIDE SLOT, FULLY INSERT.
ATTENTION: POUR EVITER LES CHOCS ELECTRIQUES,

INTRODUIRE LA LAME LA PLUS LARGE DE LA FICHE DANS
LA BORNE CORRESPONDANTE DE LA PRISE ET POUSSER
JUSQUAU FOND.

1-3

MX-G70

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.

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.

CD changer
mechanism

assembly

CD traverse

unit

Flexible cable

Fig.1

Soldering

Fig.2

1-4

Importance administering point on the safety

F102

F101

F001

MX-G70

Caution: For continued protection against risk of
fire, replace only with same type 5A/125V for
F001, 6A/125V for F101 and F102. This symbol
specifies type of fast operating fuse.

Precaution: Pour eviter risques de feux, remplacez
le fusible de surete de F001 comme le meme type
que 5A/125V, et 6A/125V pour F101 et F102.
Ce sont des fusibles suretes qui functionnes rapide.

^

1-5

MX-G70

Disassembly method

<Main body>

Removing the metal cover

(See Fig.1 to 3)

1.

Remove the six screws A on the back of the body.

2.

Remove the two screws B on both sides of the
body.

3.

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

CAUTION:

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

A

Metal cover

Metal cover

AA

Fig.1

B

Fig.2

Metal cover

B

Fig.3

1-6

MX-G70

Removing the CD changer mechanism
assembly (See Fig.4 and 5)

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

1.

Disconnect the card wire from connector CN661 on
the Main board.

2.

Remove the two screws C on the upper side of the
body and the two screws D on the back of the rear
panel.

3.

Remove the plastic rivet attaching the main board.

4.

Remove the fan connector CN705.

5.

Pull both the rear panel and the front panel assembly
to the outside, then remove the CD changer
mechanism assembly by lifting the rear part of the
assembly.

CAUTION:

To prevent damage to the CD fitting, be
sure to pull both the rear panel and the
front panel assembly enough to remove
the CD changer mechanism assembly.

Front panel assembly

C

Main board

CN661

Fig.4

CD changer mechanism assembly

Main board

CN661

Plastic rivet

Front panel assembly

Fig.5

C

CD changer
mechanism assembly

Rear panel

Rear panel

D

Removing the front panel assembly

(See Fig.6 to 10)

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

1.

Disconnect the card wires from connector CN870,
CN871 and CN315 on the main board respectively.

2.

Remove the tie band and disconnect the wire from
connector CN703 on the amplifier board.

3.

Disconnect the wire from connector CN220 on the
transformer board.

Amplifier board

CN703

Tie band

Fig.6

Main board

CN870

CN871

CN315

Front panel
assembly

Transformer board

CN220

Front panel assembly

Fig.7

Main board

1-7

MX-G70

4.

Remove the four screws E on the bottom of the
body.

5.

Release the two joints a on the lower right and left
sides of the body using a screwdriver, and remove
the front panel assembly toward the front.

Front panel assembly

E

(Bottom)

Fig.8

Front panel assembly

Joint a

Joint a

Fig.9

Front panel assembly

Fig.10

1-8

MX-G70

Removing the tuner board

(See Fig.11 and 12)

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

1.

Disconnect the card wire from connector CN1 on the
tuner board on the right side of the body.

2.

Remove the plastic rivet fixing the tuner board.

3.

Remove the two screws F on the back of the body.

Removing the rear cover / rear panel

(See Fig.12 to 15)

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

F

Joint b

CN1

Plastic rivet

Fig.11

G

Tuner board

Rear panel

Rear panel

Joint b

1.

Remove the screw G attaching the rear cover on the
back of the body.

2.

Push each tab of the four joints b in the direction of
the arrow and release.

3.

Remove the eleven screws F attaching the rear
panel.

4.

Release the joints c on each lower side of the rear
panel using a screwdriver and remove the rear panel
backward.

Note : Remove the tuner board in case of necessity.

(Refer to Fig.21)

F

F
F

Rear cover

Fig.12

Rear panel

F

Fig.13

Joint c

Fig.15

Rear panel

Rear panel

Fig.14

Joint c

1-9

MX-G70

Removing the main board

(See Fig.16 and 17)

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

1.

Disconnect the card wires from connector CN870,
CN871 and CN315 on the main board.

2.

Disconnect the flat wires from connector CN704 and
CN706 on the amplifier board.

3.

Remove the screw H attaching the main board on
the right side of the body.

4.

Disconnect connector CN211 and CN212 on the
main board from the regulator board.

CN315

Amplifier board

CN704
CN706

Front panel assembly

Main board

CN871

Plastic rivet

CN870

Fig.16

Front panel assembly

Main board

Removing the speaker board

(See Fig.18)

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

REFERENCE:

1.

Disconnect connector CN217 on the speaker board
from the regulator board.

It is not necessary to remove the main
board.

Regulator board

Regulator board

H

Fig.17

Fig.18

CN212

CN211

Speaker board

CN217

1-10

MX-G70

Removing the amplifier board / voltage
board / heat sink (See Fig.19 and 20)

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

1.

Disconnect the wires from connector CN703, CN704
and CN706 on the amplifier board respectively.

2.

Remove the two tie band attaching the wire to the
amplifier board and the voltage board.

3.

Disconnect connector CN215 on the amplifier board
and CN216 on the voltage board from the regulator
board (The heat sink and heat sink bracket will be
detached at once).

4.

Pull out the upper and lower heat sink brackets from
the heat sink respectively.

5.

Remove the four screws I attaching the amplifier
board to the heat sink.

6.

Remove the two screws J, the board bracket and
the voltage board.

Tie band

Voltage board

Regulator board

Heat sink

Voltage board

Amplifier board

CN704
CN706

CN216

Heat sink bracket

Tie band

CN703

CN215

Fig.19

Amplifier board

I

J

Heat sink bracket

I

Fig.20

1-11

MX-G70

Removing the power transformer
assembly (See Fig.21 and 22)

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

1.

Disconnect the wires from connector CN220 and
CN250 on the transformer board.

2.

Disconnect the wire from connector CN204 on the
regulator board.

3.

Remove the four screws k attaching the transformer
assembly.

Removing the regulator board

(See Fig.23)

Prior to performing the following procedure, remove
metal cover, CD changer mechanism assembly, rear
panel, tuner board, main board, amplifier board,
voltage board and speaker board.

Voltage board

Power cord

Base chassis

Regulator board

CN204

Transformer board

Tie band

Power cord stopper

Fig.21

Transformer board

CN220

CN250

CN220

Power transformer assembly

K

Power transformer
assembly

1.

Disconnect the wire from connector CN204 on the
regulator board.

2.

Remove the two screws L attaching the regulator
board.

Removing the power cord (See Fig.21)

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

1.

Disconnect the wire from connector CN250 on the
transformer board.

2.

Remove the tie band from the voltage board.

3.

Move the power cord stopper upward and pull out it
from the base chassis.

CN250

CN204

L

Regulator board

K

Tie band

Power cord stopper

Fig.22

Power transformer assembly

L

Fig.23

1-12

MX-G70

<Front panel assembly>

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

Removing the cassette mechanism
assembly (See Fig.24)

1.

Disconnect the card wire from connector CN306 on
the head amplifier & mechanism control board.

2.

Remove the four screws M and three screws M'
attaching the cassette mechanism assembly.

Removing the display system control
board (See Fig.25 to 27)

1.

Remove the five screws N attaching the stay bracket.

2.

Disconnect the card wires from connector CN316 and
CN880 on the display system control board.

Head amplifier
& Mechanism control board
CN306

M

M'

Cassette mechanism
assembly

Fig.24

N

M

M

M'

M'

N

3.

Remove the seven screws O attaching the display
system control board.

4.

If necessary, disconnect the wire from connector
CN911 on the front side of the display system control
board and unsolder FW915.

If necessary, remove the CD play board. (Fig. 28)

Removing the CD play board

(See Fig.27 and 28)

1.

Remove the three screws P attaching the CD eject
board.

2.

If necessary, unsolder FW915 on the CD eject
board.

CD play board

FW915

(Soldering)

P

P

Display system control board

O

FW915

(Soldering)

O

Fig.25

O

CN316

CN880

Fig.26

CN911

Stay bracket

O

O

Display system control board

CD play board

FW915

Display system control board

FW915

Fig.27Fig.28

1-13

MX-G70

Removing the preset / tuning switch
board (See Fig.29 and 30)

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

1.

Pull out the preset knob on the front panel.

2.

Remove the five screws Q attaching the preset /
tuning switch board.

Removing the operation switch board

(See Fig.30 and 31)

Prior to performing the following procedure, remove
the display system control board and the preset /
tuning switch board.

1.

Pull out the volume knob on the front panel and
remove the nut. Pull out the surround mode knob
and the surround woofer level knob toward the front.

Q

Preset / tuning switch board

Q

Fig.29

Preset knob

Surround mode knob

Surround woofer
level knob

2.

Remove the twelve screws R attaching the
operation switch board.

3.

Release the wire clamp.
Remove the screw R' attaching the earth terminal

4.

extending from the switch board.
Release each tab of the seven joints g retaining the

operation switch board.

Joint g

Joint g

R

R

Joints g

Nut

Volume knob

Fig.30

R

Operation
switch board

Joint g

1-14

R

Joints g

R

Fig.31

R

R

Wire clamp

R'

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

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

MX-G70

A

a

a

CN854

A

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 B' retaining the lod stopper.

4.
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 B retaining the disc stopper

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

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

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

9.
the one screw E 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

B

Earth

wire

Fig.1

A

Clamper base

A

b

Rod

c

T.Braket

Fig.2

d

CC

B'

a

Lod stopper
(C/J version only)

C

D

b

Lock lever

Clamper ass'y

Fig.3

Fig.4

Return spring

E

1-15

MX-G70

11.

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

12.
shown in Fig.6 from to the second or fifth hole on the
left side face of the CD changer mechanism assembly.

[Caution]

13.

14.

15.

Chassis assembly

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.

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.

Stopper

e

CD tray
assembly

Fig.5

Refer to Fig.7

Pulley gear

Pawl

Fig.6

CD tray assembly

g

CD
CD

CD

f

Drive unit of elevator

Fig.7

3
2

1

CD tray assembly

1-16

Motor pulley

Fig.8

Pawl ,

g

Fig.9

g'

MX-G70

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 F 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

h

i

F

F

CD loading mechanism assembly

Fig.10

F

F

CD traverse mechanism

Arrow

k

j

Fig.11

Removing the CD pick unit
(See Fig.13 )

1.

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

Lifter unit

o

Stopper

Shaft

Fig.12

CD Pickup unit

n

m

Shaft

p

Stopper

Fig.13

Arrow

CD loading

mechanism

Shaft

Cam gear

l

1-17

MX-G70

Removing the try select switch board
(See Fig.14)

1.2.Remove the two screws G retaining the tray select
switch board.
Disconnect the tray select switch board from connector
CN804 on the CD servo control board.

Removing the cam unit
(See Fig.15 ~17 )

1.

Remove the CD loading mechanism assembly.

2.

While turning the cam gear "q", align the Paul "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 Paul "s"

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

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

Chassis assembly

Drive unit

CN851

CN854

Fig.14

Cam gear

Tray select
switch board

CN804

q

G

Drive unit

Cylinder gear

r

Cam gear

H

s

Fig.15

H

q

Cams R1, R2 assembly

Cam unit

J

1-18

Fig.16

Select lever

Fig.17

MX-G70

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

1.

Remove the two screws I retaining the gear bracket
(See Fig.18).

2.

While pressing the pawl "t" fixing the gear bracket in the
arrow direction, remove the gear bracket
(See Fig.18).
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. 19).
Remove the belts respectively from the right and left

4.
actuator motor pulleys and pulley gears(See Fig. 18).
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. 20).

[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. 21.

Chassis assembly

Pulley gear

Gear bracket

Belt

Motor pulley

I

Fig.18

Actuator motor

Pulley gear
Belt
Motor pulley

I

Pawl

t

u

Gear bracket

Fig.19

Assembly and Configuration Diagram

Pulley gear

Gear B

v

v

Fig.20

Pulley gear

Gear B

Cylinder gear

Gear C

Select gear

Gross gear L

Fig.21

Gross gear U

Gear C

1-19

MX-G70

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

Remove the slit washer fixing the cams R1 and R2

1.
assembly.
By removing the two pawls "w" fixing the cam R1,

2.
separate R2 from R1.
Remove the slit washer fixing the cam gear "q".

3.
Pull out the cam gear "q" from the C.G. base assembly.

4.

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

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

[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).

Slit washer

Cam gear q

J

Slit washer

Cam R2

Pawl

w

Cam R1

Cam switch board

C.G. base assembly

Pawl

w

Notch

Pawl

x

Cylinder
gear

Drive unit

Fig.22

Cam gear q

Cam R1, R2 assembly

Gear unit

Gear bracket

Fig.23

1-20

MX-G70

< 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 / recording & eraser 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. Remove the flexible P.C.board from the chassis
base.

5. Remove the spring "a" from behind the playback /
recording head.

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

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

8. The recording and eraser heads should also be
removed similarly according to Steps 1~7 above.

Flexible
P.C.board

Cassette mechanism

Trigger armHead mount

Fig.1

Playback/Recording &
eraser head

(Mechanism A side)

Flywheel R

Spring "a"

Trigger arm

Reassembling the playback, recording

and eraser heads (See Fig.3)

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
as shown in Fig.3.

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

CN301

Head amplifier & mechanism
control P.C. board

Fig.2

Playback head

Spring "a"

CN302

FPC holder

Fig.3

Flywheel R

(Mechanism A side)

Reversing azimuth
screw

Head
mount

Flexible
P.C.board

Head amplifier &
mechanism control
P.C. board

(Mechanism B side)

1-21

MX-G70

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

1.Remove the cassette mechanism assembly.

2.After turning over the cassette mechanism
assembly,remove the five screws "A" retaining
the head amplifier & mechanism control board.

3.Disconnect the connectors CN303 on the board
and the connectors CN301 and on CN302 both
the right and left side reel pulse boards.

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

Removing the capstan motor assembly

(See Fig.5 to 7)

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).

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.(See Fig.6 and 7)

A

Flexible
board

Head amplifier &
mechanism control board

AA

CN303

CN302 CN301

Flexible
board

Fig.4

BB

Capstan motor
assembly

AA

1-22

Capstan
belt A

Fig.5

Capstan motor

Capstan
belt A

Capstan
belt B

Motor pulley

Fig.7 Fig.6

BBBB

Capstan
belt B

MX-G70

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

C

Capstan motor

Joint
bracket

C

Fig.8

Flywheel R Flywheel L

Flywheel R Flywheel L

Fig.10

Removing the reel pulse 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.

hi

Solenoid

c

a

d

Slit
washer "a"

Fig.9

e

f

b

Slit
washer "b"

Reel pulse board

g

Solenoid

Fig.11

1-23

MX-G70

< Speaker section >

Attention which adheres to speaker box

The speaker box of this model is a unit supply.

Therefore, we do not supply it as individual parts though
the method of disassembling the speaker box has been
described.

Removing the side cover (See Fig.1)

1.

Remove the six screws A on the side of the body.

Removing the squawker speaker

(See Fig.2)

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

1.

Remove the four screws B on the side of the body.

2.

Disconnect the red and black wires from the speaker
terminals on the squawker speaker.

A

A

Side cover

A

A

Fig.1

B

Squawker speaker

Removing the front cover (See Fig.3 to 6)

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

1.

Pull out the saran net toward the front while
disengaging the four joints a.

2.

Remove the two screw cover and two screws C
attaching the inner front cover.

Front cover

Screw cover

Screw cover

B

Fig.2

Joints a

Joints a

1-24

Fig.4

Saran net

Fig.3

3.

Remove the two screws D and E respectively.

4.

Remove the front cover toward the front and
disconnect the yellow and black wires from the two
tweeter speaker terminals.

MX-G70

DD

Front cover

Removing the woofer speaker (See Fig.7)

Prior to performing the following procedure, remove
the side cover and the front cover.

1.

Remove the four screws F on the front of the body.

2.

Pull out the woofer speaker toward the front and
disconnect the wire (yellow and black,blue and
black) from the two speaker terminals.

Removing the tweeter speaker

(See Fig.8)

Prior to performing the following procedure, remove
the side cover and the front cover.

1.

Remove the two screws G attaching the tweeter
speaker on the back of the front cover.

C

Tweeter speaker

C

EE

Fig.5

Front cover

G

Tweeter speaker

F

Fig.6

F

Woofer speaker

Fig.7Fig.8

1-25

MX-G70

Adjustment method

Measurement instruments required
for adjustment

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

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
AC120V(60Hz)

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)
Sub woofer VOL. : Minimum
Sound mode : OFF
Main VOL. : 0 Minimum
Traverse mecha set position : Disc 1

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.

1-26

Arrangement of adjusting positions

MX-G70

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

1-27

MX-G70

Tape recorder section

Items Measurement

Confirmation
of head angle

Confirmation
of tape speed

conditions

Test tape
:TMT7036(10kHz)
Measurement
output terminal
:Speaker terminal
Speaker R
(Load resistor:6 )
:Headphone terminal

Test tape
:VTT712(3kHz) or
TMT7036(3kHz)
Measurement
output terminal
:Headphone terminal

1.Playback the test tape TMT7036(10kHz).

2.With the playback mechanism or recording &
playback mechanism, adjust the head azimuth
screw so that the forward and reverse output
levels become maximum.After adjustment,lock
the head azimuth at least by half a turn.

3.In either case,this adjustment should be
performed in both the forward and reverse
directions with the head azimuth screw.

<Constant speed>
Adjust VR301 so that the frequency counter reading
becomes 3,000Hz 60Hz when playing back the
test tape VTT712(3kHz)with the playback mechanism
or playback and recording mechanism after ending
forward winding of the tape.

Reference values for confirmation items

Items Measurement

Double tape
speed

conditions

Test tape
:TMT7036(10kHz)
Measurement
output terminal
:Speaker terminal
Speaker R
(Load resistance:6 )
measurement
output terminal
:Headphone terminal

After setting to the double speed motor, confirm
that the frequency counter reading becomes
4,800+400/-300Hz when the test tape VTT712
(3kHz) has been play back with the playback
mechanism.

Measurement method

Measurement method

Standard

values

Maximum
output

Tape speed
of decks
(A and B)
:3,000Hz
60Hz

Standard

values

4,800+400/

-300Hz

Adjusting

positions

Adjust the head
azimuth screw
only when the
head has been
changed.

VR301

Adjusting

positions

Playback
mechanism side

Difference
between the
forward and
reverse speed.
P.mecha and
R/P mecha
speed

Wow & flutter

1-28

Test tape
:TMT7036(10kHz)
Measurement
output terminal
:Headphone terminal

When the test tape VTT712(3kHz) has been played
back with the playback mechanism or recording and
playback mechanism at the beginning of forward
winding, the frequency counter reading of the
difference between both of the mechanisms should
be 6.0Hz or less.

When the test tape VTT712(3kHz) has been played
back with the playback mechanism or recording and
playback mechanism at the beginning of forward
winding the frequency counter reading of wow &
flutter should be 0.25% or less(WRMS).

60Hz or
less

with in

0.25%
JIS(WTD)

Both the playback
and recording &
playback
mechanism

Both the playback
and recording &
playback
mechanism

Electrical performance

Items Measurement

Adjustment of
recording bias
current
(Reference
value)

conditions
*Mode : Forward or
reverse mode
*Recording mode
*Test tape
: AC-225
Measurement output
terminal
:Both recording and
headphone terminals

Measurement method

1.With the recording and playback mechanism,
load the test tapes(AC-225 to TYP ),and set the
mechanism to the recording and
pausing conditions in advance.

2.After connecting 100 in series to the recorder
head,measure the bias current with a valve
voltmeter at both of the terminals.

3.After resetting the [PAUSE] mode,start recording.
At this time,adjust VR101 for LcH and VR201 for
RcH so that the recording bias current values
become 4.0 A (TYP ).

Standard

values
AC-225
:4.20 A

MX-G70

Adjusting

positions

LcH
:VR101
RcH
:VR201

Adjustment of
recording and
playback
frequency
characteristics

Reference frequency
:1kHz and 10kHz
(REF:-20dB)
Test tape
:TYP AC-225
Measurement input
terminal
:OSC IN

1.With the recording and playback mechanism,load
the test tape(AC-225 to TYP ),and set the
mechanism to the recording and pausing condition
in advance.

2.While repetitively inputting the reference frequency
signal of 1kHz and 10kHz from OSC IN, record and
playback the test tape.

3.While recording and playing back the test tape in
TYP ,adjust VR101 for LcH and VR201 for RcH
so that the output deviation between 1kHz and
10kHz becomes -1dB 2dB.

Reference values for electrical function confirmation items

Items Measurement

Recording
bias frequency

conditions

*Recording and
playback side forward
or reverse
*Test tape
:TYP AC-225
*Measurement
terminal BIAS TP on
P.C.board

1.With the recording and playback mechanism.
load the test tape (AC-225 to TYP ),and set the
mechanism to the recording and pausing
conditions in advance.

2.Confirm that the BIAS TP frequency on the
P.C.board is 100kHz 6kHz.

Measurement method

Output
deviation
between
1kHz and
10kH
:-1dB 2dB

Standard

values
100kHz
+9kHz

-7kHz

LcH
:VR101
RcH
:VR201

Adjusting
positions

Eraser current
(Reference
value)

*Recording and
playback side forward
or reverse
*Recording mode
*Test tape
:AC-225
Measurement terminal
Both of the eraser
head

1.With the recording and playback mechanism,
load the test tapes(AC-225 to TYP ),and set the
mechanism to the recording and pausing condition
in advance.

2.After setting to the recording conditions,connect
1M in series to the eraser head on the recording
and playback mechanism side,and measure the
eraser current from both of the eraser terminal.

TYP
:75mA

1-29

MX-G70

Flow of functional operation until TOC read

Power ON

Play Key

Slider turns REST
SW ON.

Automatic tuning
of TE offset

Check Point

Confirm that the voltage at the pin5
of CN801 is "H"\"L"\"H".

Tracking error waveform at TOC reading

Approx.3sec

Tracking
servo
off states

Automatic measurement
of TE amplitude and
automatic tuning of
TE balance

VREF

pin 25 of
IC601(TE)

Approx

1.8V

Disc states
to rotate

Tracking
servo
on states

Disc to be
braked to stop

TOC reading
finishes

500mv/div
2ms/div

Fig.1

Laser ON

Detection of disc

Automatic tuning of
Focus offset

Automatic measurement of
Focus S-curve amplitude

Disc is rotated

Focus servo ON
(Tracking servo ON)

Automatic measurement of
Tracking error amplitude

Automatic tuning of
Tracking error balance

Check that the voltage at the
pin40 of IC651 is + 5V?

Confirm that the Focus error
S-cuve signal at the pin28 of
IC651 is approx.2Vp-p

Confirm that the signal from
pin24 IC651 is 0V as a
accelerated pulse during
approx.400ms.

Confirm the waveform of
the Tracking error signal.
at the pin 25 of IC601 (R604)
(See fig-1)

1-30

Automatic tuning of
Focus error balance

Automatic tuning of
Focus error gain

Automatic tuning of
Tracking error gain

TOC reading

Play a disc

Confirm the eys-pattern
at the lead of TP1

MX-G70

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

1.25V 0.22Vp-p?

YES

O.K

NO

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.

1-31

MX-G70

Description of major ICs

AN7345(IC302) PB/REC AMP

1. Block diagram

2. Pin Function

Pin

Symbol

No.

1

R1

2

R2

L1

L2

NF1

24

1

R1

I/O

I

Playback amplifier input

Playback amplifier input

I

R2

23

2

22

3

NF2

AMP

AMP

Pre

Pre

OUT1

4

OUT2

Function

EQ1

2021

EQ

CTRL

5

EQ2

CTL1

Pre

Source

CTRL

6

CTL2

RIN1

RNF1

1819

17

78

RIN2

RNF2

Pin
No.

13

14

9

EQ

CTL

ALC

10 11

LC

LPF GND

I/O

I

I

VCC

RF

141516

13

REPPLE

REJ

12

Ripple filter

ROUT1

ALC
AMP

ALC
AMP

ROUT2

Symbol

Vcc Power supply

RF

Function

3

NF2

4

OUT2 Playback amplifier output

EQ2 I

5

CTL2 I Pre Amplifier input switching time

6

RIN2 I

7

RNF2 I Recording amplifier negative feedback

8

ROUT2

9

LC I

10

11

LPF

GND I

12

I

Playback amplifier negative feedback

O

Equalizer

constant

Recording amplifier input

Recording amplifier output

O

ALC low cut

ALC low pass filter

I

EQCTL EQ control

15

16

ROUT1

17

RNF1 Recording amplifier negative feedback
RIN1

18

CTL1

19

20

EQ1 Equalizer

21

OUT1

NF1

22

L2 I

23

24

L1

I

O

Recording amplifier output

I

I Recording amplifier input

Pre amplifier input switching control

I

I

Playback amplifier output

O

Playback amplifier negative feedback

I

Playback amplifier input

Playback amplifier input

I

1-32

BA15218F-XE (IC652) / BA15218N (IC481,501,502,526,546,571) : Dual op. amp.

1. Pin layout

MX-G70

OUT1 1

-IN1 2

+IN1 3

VEE 4

2. Block diagram

Vcc

-IN

+IN

1

2

R1

Q5

Q1

Q2

D1

Q3 Q4

8 Vcc

7 OUT2

6 -IN2

5 +IN2

C2

Q9

R5

Q6

Q8

Q10

Q7

R7

Q11

R6

Q12

R8

Q18Q13

OTHER

CH

Q19

Q17Q16

VEE

C1

R3R2

R4

OUTPUT

Q14 Q15Q114

R9

1-33

MX-G70

BA3126N(IC301) : R/P Switch

S W

R E C

G

123456789

P / B

S W

C O N T .

G N D

LB1641 (IC851,IC852) : DC motor driver

1. Pin layout

1 2 3 4 5 6 7 8 9

GNDOUT1 P1

VZ IN1 IN2

2. Pin function

Input Output

IN1 IN2 OUT1 OUT2

0 0 0 0
1 0 1 0
0 1 0 1
1 1 0 0

VCC1

VCC2 P2

10

OUT2

CLOCKWISE

COUNTER-CLOCKWISE

V c c

Mode

Brake

Brake

P / B

S W

G

S W

R E C

1-34

BA3835S (IC812) : SPI B.P.F.

1.Block Diagrams

MX-G70

BIASC

VREFC

RREF

DIFOUT

N.C.

N.C.

CIN

AIN

VCC

1

2

3

4

5

6

7

8

9

2.Pin Function
No. Symbol

1
2
3
4
5
6
7
8

9
10
11
12
13
14
15
16
17
18

BIASC

VREFC

RPEF

NC
NC

NC
CIN
AIN

VCC
SPI-A
SPI-B
SPI-C

SPICSB

NC
NC

TEST

AOUT

GND

A-C

DIF

105Hz
BPF

340Hz
BPF

1kHz
BPF

3.4kHz
BPF

10.5kHz
BPF

REFERENCE
CURRENT

PEAK
HOLD

PEAK
HOLD

PEAK
HOLD

PEAK
HOLD

PEAK
HOLD

I/O

-

-

-

-

-

-

­I

­O
O
O
O

-

-

­O

-

BIAS

VREF

RES

RES

MPX

RES

RES

RES

DEC

18

17

16

15

14

13

12

11

10

GND

AOUT

TEST

N.C.

N.C.

SEL

C

B

A

Function
Decoupling condenser connection terminal.
Decoupling condenser connection terminal.
Reference resistance connection terminal.
Non connect.
Non connect.
Non connect.
Connected to GND of audio system through a condenser.
Inputs the audio signal through a condenser.
Power supply terminal.
Output selection control terminal.
Output selection control terminal.
Output selection control terminal.
Output selection control terminal.
Non connect.
Non connect.
Connected to GND upon normal use.
Multi-plexor output terminal.
Connect to GND.

1-35

MX-G70

BU2092/F(IC811):PORT EXPANDER

1.Terminal Layout

Vss

DATA

CLOCK

LCK

Q0

Q1

Q2

Q3

Q4

1

2

3

4

5

6

7

8

9

CONTROL

CIRCUIT

12BIT SHIFT RESISTER

12BIT STRAGE RESISTER

OUTPUT BUFFER(OPEN DRAIN)

18

17

16

15

14

13

12

11

10

Vdd

OE

Q11

Q10

Q9

Q8

Q7

Q6

Q5

2.Pin Function
Pin No.

1
2
3
4

5~16

17
18

Symbol

Vss

DATA

CLOCK

LCK

Q0~Q11

OE

Vdd

I/O

­I
I
I

O

I

-

Function

Connect to GND
Serial Data input
Shift Clock of Data
Latch Clock of Data
Parallel Data Output

Latch Data L H
OUTPUT ON OFF

Output Enable
Power Supply

1-36

LA1838(IC1): FM AM IF AMP&detector, FM MPX decoder

1. Block Diagram

MX-G70

30

ALC

BUFF

FM
S-METER

FM IF

1

2. Pin Function

Pin

Symbol

No.

FM IN

1

AM MIX

2

3

FM IF

AM IF

4

GND

5
6

TUNED

STEREO

7

8

VCC

9

FM DET

10

AM SD

FM VSM

11

AM VSM

12
13

MUTE

14

FM/AM

MONO/ST O

15

29

AM

OSC

SD
COMP

S-CLRVE

PM
DET

2

I/O

I

This is an input terminal of FM IF

28

REG

AM

MIX

AM/FM
IF-BUFF

3

27

FM

RF.AMP

AM IF

4

26

AGC

AM
S-METER

GND

Function

DET

5

signal.
This is an out put terminal for AM

O

mixer.

I

Bypass of FM IF

Input of AM IF Signal.

I

I

This is the device ground terminal.

When the set is tuning, this terminal

O

becomes "L".

O

Stereo indicator output. Stereo "L",
Mono: "H"

III

This is the power supply terminal.

I

FM detect transformer.

I

This is a terminal of AM ceramic filter.

O

Adjust FM SD sensitivity.

O

Adjust AM SD sensitivity.

I/O

When the signal of IF REQ of IC121(
LC72131) appear, the signal of FM/AM
IF output. //Muting control input.

Change over the FM/AM input.

I

"H" :FM, "L" : AM

Stereo : "H", Mono: "L"

25

TUNING
DRIVE

6

24

STEREO
DRIVE

7

22

23

P-DET

VCC

89

Pin

Symbol

No.

16

L OUT

17

R OUT

18

19

20

21

22

23

24

25

26

27
28

29

30

L IN

R IN

RO
LO

IF IN

FM OUT
AM DET

AM AGC

AFC

AM RF

REG

AM OSC

OSC BUFFER

21

DECODER
ANIT-BIRDIE

VCO
384KHz

10

20

STEREO
5N
SW

FF
38k

11

I/O

O

Left channel signal output.

O

Right channel signal output.

Input terminal of the left channel post

I

18

19

MUTE

FF

/

19k

2

12 13

FF
19k

/

LS

Function

17 16

PILOT
DET

14

AMP.

Input terminal of the right channel

I

post AMP.
Mpx Right channel signal output.

O
O

Mpx Left channel signal output.

I

Mpx input terminal

FM detection output.

O

AM detection output.

O

This is an AGC voltage input terminal

I

for AM

I

This is an output terminal of voltage
for FM-AFC.

AM RF signal input.

I

Register value between pin 26 and pin28

O

desides the frequency width of the
input signal.

I

This is a terminal of AM Local
oscillation circuit.

AM Local oscillation Signal output.

O

15

1-37

MX-G70

LA6541-X (IC801) : Servo driver

1. Pin Layout & block diagram

Vcc Vref Vin4 Vg4 Vo8 Vo7

24 23

11k
ohm

22

20

21

19

Vcc

Gnd

Vo6 Vo5 Vg3 Vin3 Cd Res

18

17 16

- +

- +

Level
shift

Level
shift

11k
ohm

1

2

3456

Vcc Mute Vin1 Vg1 Vo1 Vo2 Vo3 Vo4 Vg2 Vin2 Reg

B T L
driver

B T L
driver

Gnd

B T L
driver

B T L
driver

7 8 9101112

Level
shift

Level
shift

2. Pin function

Pin

Symbol Function

No.

1

10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

2
3
4
5
6
7
8
9

Vcc

Mute

Vin1

Vg1
Vo1
Vo2
Vo3
Vo4
Vg2

Vin2

Reg Out

Reg In

Res

Cd

Vin3

Vg3
Vo5
Vo6
Vo7
Vo8
Vg4

Vin4

Vref

Vcc

Power supply (Shorted to pin 24)
All BTL amplifier outputs ON/OFF
BTL AMP 1 input pin
BTL AMP 1 input pin (For gain adjustment)
BTL AMP 1 input pin (Non inverting side)
BTL AMP 1 input pin (Inverting side)
BTL AMP 2 input pin (Inverting side)
BTL AMP 2 input pin (Non inverting side)
BTL AMP 2 input pin (For gain adjustment)
BTL AMP 2 input pin
External transistor collector (PNP) connection. 5V power supply output
External transistor (PNP) base connection
Reset output
Reset output delay time setting (Capacitor connected externally)
BTL AMP 3 input pin
BTL AMP 3 input pin (For gain adjustment)
BTL AMP 3 output pin (Non inverting side)
BTL AMP 3 output pin (Inverting side)
BTL AMP 4 output pin (Inverting side)
BTL AMP 4 output pin (Non inverting side)
BTL AMP 4 output pin (For gain adjustment)
BTL AMP 4 output pin
Level shift circuit's reference voltage application
Power supply (Shorted to pin 1)

15

11k
ohm

14

13

RESET

Regulator

11k
ohm

out

Reg
In

1-38

LC72136N (IC2) : PLL frequency synthesizer

1. Pin layout

FM/AM

CLOCK

FM/ST/VCO

AM/FM

2. Block diagram

XT

CE

DI

DO

SDIN

1
2
3
4
5
6
7
8
9
10
11

22
21
20
19
18
17
16
15
14
13
12

XT
GND
LPFOUT
LPFIN
PD
VCC
FMIN
AMIN

IFCONT
IFIN

MX-G70

1

22

16

15

3

4
5

6

17

21

3. Pin function

Pin

Symbol

No.
1
2
3

4

5
6

7

8
9
10
11

XT

FM/AM

CE

DI

CLOCK

DO

FM/ST/VCO

AM/FM

LW

MW

SDIN

Reference

Driver

Swallow Counter

1/2

C

2

B

I/F

Power

on

Reset

Function

I/O

X'tal oscillator connect (75kHz)

I

LOW:FM mode

O

When data output/input for 4pin(input) and

I

Swallow Counter

1/16,1/17 4bit

1/16,1/17 4bit

12bit

Programmable

DriverS

Data Shift Register & Latch

7821113

6pin(output): H
Input for receive the serial data from

I

controller
Sync signal input use

I

Data output for Controller

O

Output port
"Low": MW mode

O

Open state after the power on reset

O

Input/output port

I/O

Input/output port

I/O

Data input/output

I/O

Phase

Detector

Charge Pump

Unlock

Detector

Universal

Counter

Pin

Symbol

No.
12

IFCONT

13
14

15

16
17

18

19

LPFOUT

20
21
22

IFIN

AMIN

FMIN

VCC

PD

LPFIN

GND

XT

18

19
20

12

I/O

Function
IF counter signal input

I

IF signal output

O

Not use

-

AM Local OSC signal output

I

FM Local OSC signal input

I

Power suplly(VDD=4.5-5.5V)

­When power ON:Reset circuit move
PLL charge pump output(H: Local OSC

O

frequency Height than Reference frequency.
L: Low Agreement: Height impedance)
Input for active lowpassfilter of PLL

I

Output for active lowpassfilter of PLL

O

Connected to GND

­X'tal oscillator(75KHz)

I

1-39

MX-G70

MN101C35DBC1(IC810) : System controller

Pin function (1/2)

Pin No.

1
2
3
4
5
6
7
8

9,10

11

12,13

14
15

16C19

20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46

47~63

Symbol

KCMND

MSTAT

KCLK

DATAOUT

DATAIN

CK
NC

VDD

OSC2,1

VSS

NC

MMOD

VREF-

KEY1~4
SLCKEY1
SLCKEY2

NC
SPIDTI
VREF+

MRDY

RESET

BASS VOL+

BASS VOL-

AUX MUTE

RDSDATA/KARA

SPI A
SPI B

REMIN

PHOTOA
PHOTOB

SOUNDMODE+

RDS_CLK

PRT

TAPE LED

ECON

POUT
VOLDA/EXT
VOLCK/EXT

EXTCE
SLCCE

VC3 RESET

G17~G1

I/O

O

I
O
O

I
O

-

-

I/O

-

-

-

-

I

I

I

-

I

-

I

I

I

I
O

I
O
O

I

I

I

I

I

I
O
O
O
O
O
O
O
O
O

Function

VC3 Serial data output
VC3 status input
VC3 Serial clock
SLC/TUNER data output
TUNER data input
SLC/TUNER clock
Not used
Power supply +5V
Oscillation terminal (8MHz)
Connect to GND
Not used
Connect to GND
Connect to GND
Key matrix input 1~4
SLC Key input 1
SLC Key input 2
Not used
SPI Analog data input
AD +5V
VC3 Ready
Micon reset
Bass volume +
Bass volume ­AUX muting
RDS Data / Karaoke
SPI A data
SPI B data
Remote control signal input
SLC Photo-A
SLC Photo-B
Soundmode reverse
RDS Clock
Protector input
Tape LED
Economy ON
Power ON
Volume / EXT IC Data
Volume / EXT IC CLK
EXT IC Chip select
SLC Chip enable
VC3 Reset

FL Display grid

1-40

Pin function (2/2)

MX-G70

Pin No.

64~85

86
87
88
89
90
91
92
93
94
95
96
97
98
99

100

Symbol

P22~P1

TUCE

SMUTE

SEARCH LE

CD1 LED
CD2 LED
CD3 LED

R SEARCH

MSI

MPX

INH

F SEARCH

VOL -

VOL +

SOUNDMODE

VPP

I/O

O
O
O
O
O
O
O

I
I
I
I
I
I
I
I

-

Function

FL segment control signal output
Tuner chip enable
System mute
Skip LED
LED Control signal output (CD1)
LED Control signal output (CD2)
LED Control signal output (CD3)
Reverse skip
Music scan input
Tuner stereo indicator
Backup mode detect
Forward skip
Rotary encoder VOL­Rotary encoder VOL+
Soundmode foeward

-B for FL

1-41

MX-G70

MN662748RPM (IC651) : Digital servo & digital signal processor

1. Pin layout

2.Block diagram

LRCKIN(MSEL)

BCLK(SSEL)
SRDATAIN
(PSEL)

IOSEL

CLVS

CRC

BLKCK

CLDCK

SBCK
SUBC

DEMPH

SSEL

SQCK

SUBQ

SS2

AV
AV

DD2

PCK

EFM

PLLF

PLLF2

DSLF
IREF
DRF
ARF
RSEL
PSEL

MLD
MCLK
MDATA

VCOF2

STAT

FLAG6(RESY)

VCOF
BYTCK
SMCK
FCLK

PMCK(PLAY)

CSEL
MSEL
X2

X1

DIGITAL
DE-EMPHSIS

SUB
CODE
BUFFER

DSL/
PLL
VCO

VCO

TIMING
GENERATOR
PITCH
CONTROL

20 ~ 1

21

~

40

41 ~ 60

8TIMES
OVER SAMPLING
DIGITAL FILTER

CD-TEXT
BUFFER

EFM
DEMODULATION

SYNC
INTERPOLATION

SUBCODE
DEMODULATION

MICRO
COMPUTER
INTERFACE

CONVERTER

A/D

80

~

61

1bit
DAC
PWM
LOGIC

16k
SRAM

CIRC
ERROR
CORRECTION
DE-INTERLEAVE

SERVO

CPU

PWM

PWM

OUTPUT

INPUT PORT

(R)

(L)

DIGITAL
AUDIO
INTERFACE

CLV
SERVO

INTERPOLATION
SOFT MUTING DIGITAL
ATTENUATION

D/A
CONVERTER

PORT

SERVO
TIMING GENERATOR

AV

SS1

AV

DD1

OUTR

OUTL

FLAG
IPFLAG

TX

ECM
ECS

PC

LRCK
SRDATA
BCLK
DMUTE

TOFS
KICK
TRV
V

REF

TVD
TRD
FOD
TBAL
FBAL

TLOCK
FLOCK

LDON
WVEL
SENSE

1-42

DD

V

SS

V

DD1

DV

SS1

DV

RST

TEST

FE

TE

RFENV

TRCRS

VDET

BDO

OFT

RFDET

3. Pin function

Pin
No.

1

2

3

4
5

6

7

8

9
10
11

12
13

14
15
16

17

18
19
20
21
22

23

24

25
26

27
28

29

30

31

32

33
34
35

36

37
38

39
40

Dymbol

BCLK
LRCK
SRDATA
DVDD1
DVSS1
TX

MCLK

MDATA
MLD
SENSE
FLOCK
TLOCK

BLKCK

SQCK
SUBQ
DMUTE

STATUS

RST

SMCK

PMCK

TRV

TVD

PC
ECM

ECS
KICK

TRD
FOD

VREF

FBAL
TBAL
FE
TE
RF ENV

VDET
OFT
TRCRS

RFDET

BDO

LDON

I/O

O
O
O

O

I

I
I

O

O
O
O

I

O

O

I

O
O

O

O

O
O
O

O
O

O

Function

Not used
Not used

Not used

I

Power supply (Digital)

I

Connected to GND
Digital audio interface output

CPU command clock signal input

(Data is latched at signal's rising point)

CPU command data input

CPU command load signal input

Sense signal output

Focus lock signal output Active :Low
Tracking lock signal output Active :Low

sub-code/block/clock signal output

Outside clock for sub-code Q resister input

Sub-code Q -code output

I

Connected to GND
Status signal

(CRC,CUE,CLVS,TTSTOP,ECLV,SQOK)
Reset signal input (L:Reset)

I

Not used

I

Not used

Traverse enforced output

Traverse drive output

I

Not used

Spindle motor drive signal (Enforced
mode output) 3-State
Spindle motor drive signal (Servo error

signal output)

Kick pulse output

Tracking drive output

Focus drive output
Reference voltage input pin for D/A

I

output block (TVD,FOD,FBA,TBAL)
Focus Balance adjust signal output

Tracking Balance adjust signal output

Focus error signal input (Analog input)

I

Tracking error signal input (Analog input)

I
I

RF envelope signal input (Analog input)
Vibration detect signal input (H:detect)

I

Off track signal input (H:off track)

I

Track cross signal input

I

RF detect signal input (L:detect)

I

BDO input pin (L:detect)

I

Laser ON signal output (H:on)

Pin
No.

41
42
43
44
45
46

47

48
49
50
51

52
53

54
55

56

57

58
59
60
61

62

63

64

65

66
67

68

69

70
71

72

73

74

75

76

77

78

79

80

Symbol

PLLF2

TOFS

WVEL
ARF

IREF

DRF

DSLF

PLLF

VCOF
AVDD2
AVSS2

EFM

PCK/

DSLB
VCOF2
SUBC
SBCK

VSS

XI
X2
VDD
BYTCK

CLDCK

FCLK
IPPLAG

FLAG
CLVS

CRC
DEMPH

RESY

IOSEL
TEST
AVDD1
OUT L
AVSS1
OUT R
RSEL
CSEL
PSEL

MSEL

SSEL

I/O

Not used

II

Not used

I

Not used

I

RF signal input
Reference current input pin

I

Bias pin for DSL

I

I/O

Loop filter pin for DSL
Loop filter pin for PLL

I/O

I

Not used

I

Power supply (Analog)
Connected to GND (Analog)

II

Not used

O

DSL balance output

I

The external circuit is regulated for crystal.

I

Not used

I

Not used

Connected to GND (for X'tal oscillation

I

circuit)

I

Input of 16.9344MHz X'tal oscillation circuit

O

Output of X'tal oscillation circuit

I

Power supply (for X'tal oscillation circuit)

I

Not used

I

Not used

I

Not used

I

Not used

I

Not used

I

Not used

I

Not used
Not used

I

Not used

III

pull up
pull up

Power supply (Digital)

O

Lch audio output

I

Connected to GND

O

Rch audio output

II

pull up
Connected to GND

I

Connected to GND

I

Connected to GND

I

Pull up

Function

MX-G70

1-43

MX-G70

STK402-050 (IC602) : Power amp.

1.Pin layout

115

2.Block diagram

4

R1

TR7

8

TR9

R13

TR4

R6

C1

1

TR1

2

TR3

R2

TR2

R3

R4

D1

SUB

R5

13

TR5

TR6

TR8

R7

1256710

TR10

11

R8

TR12

TR13

R9

TR11

R10

C2

R11

R12

TR14 TR15

TR16

R14

9

14

15

1-44

TDA7439 (IC436) : Control volume

1.Pin layout

1

SDA

2

CRE

3

Vs

4

AGND

5

ROUT

6

LOUT

7

R-IN4

8

R-IN3

9

R-IN2

10

R-IN1

11

L-IN1

12

L-IN2

13

L-IN3

14

L-IN4

MUXOUTL

15

2.Block diagram

TDA7439

30

CSL

29

DIG GND

28

TREBLE(R)

27

TREBLE(L)

26

MIN(L)

25

MOUT(L)

24

BOUT(L)

23

BIN(L)

22

BOUT(R)

21

BIN(R)

20

MOUT(R)

19

MIN(R)

18

INR

17

MUXOUTR

16

INL

MX-G70

L-IN1
L-IN2

L-IN3
L-IN4

R-IN1

R-IN2

R-IN3
R-IN4

11

12

13
14
10

MIN(L)

MIDLE

25

MOT(L)

23

G

0/30dB
2dB STEP

INL

MUXOUT

15 16 27

VOLUME

2

I C BUS DECODER LATCHES

TREBLE

TREBLE(L)

26

9

G

VOLUME

TREBLE

MIDLE

8
7

INPUT
MULTIPLEXER
GAIN

17

18

201928

BIN(L)

24

BASS

BASS

2221

BOUT(L)

SPEAKER
ATT
LEFT

SPEAKER
ATT
RIGHT

SUPPLY

2

6

30

1

29

5

3

4

AGND

LOUT

SCL
SDA

DIG-GND

ROUT

Vs

INR

CREF

MUXOUT

MIN(R)

TREBLE(R)

BIN(R)

MOUT(R)

BOUT(R)

1-45

MX-G70

VICTOR COMPANY OF JAPAN, LIMITED

AUDIO & COMMUNICATION BUSINESS DIVISION
PERSONAL & MOBILE NETWORK BUSINESS UNIT. 10-1,1chome,Ohwatari-machi,Maebashi-city,371-8543,Japan

(No.20920)

Printed in Japan
200103(V)