JVC MXJ-270-V Service manual

SERVICE MANUAL

COMPACT COMPONENT SYSTEM

MX-J270V

RM-SMXJ111V REMOTE CONTROL

CLOCK

TIMER

1

2 3

–+

SELECT

4 5 6

ECHO SET

7 8 9

10+10

PREV NEXT RETURN SELECT

A – TAPE - B

REC PAUSE

SHIFT FM MODE

SOUND

VOLUME

MODE

MX-J270V

US
UX

STANDBY

PLAY & EXCHANGER

VIDEO CD

1 BIT

DUAL D/A CONVERTER

PHONES

TAPE

MIC LEVEL

AUX

MIN

MAX

ON SCREEN

SLEEP

V.INTRO

HIGHLIGHT

PLAY MODE

CD3CD2CD1

STILL

C D

TAPE

AUX

FM/AM

i

KEY
CONTROL

I

MIC

SP-MXJ270V

NTSC/PAL COMPATIBILITY

MX-J270V

KEY CONTROL

MPX/V.REPLACE/V.MASKING

REC

START/STOP

– PRESET +

NEXT

EJECT EJECT

TUNING / VCD NUMBER

–

SOUND MODE ACTIVE BASS EX.

AUTO REVERSE

DUBBING

CD REC START

PLAY

PREV

REVERSE MODE TAPE A/B

AUTO REVERSE

CA-MXJ270V

ECHO

+

CD

CD

CD

REC/PLAY

NTSC/PAL PAL AUTO

CD

CD

CD

VOLUME

+

–

RANDOM

CD

SELECT

REPEAT

FM /AM

SP-MXJ270V

Area Suffix

Singapore

Saudi Arabia

Contents

Safety Precautions
Important for laser products
Preventing static electricity
Disassembly method
Adjustment method

COPYRIGHT 2000 VICTOR COMPANY OF JAPAN, LTD.

1-2
1-3
1-4
1-5
1-22

PlayBack

Control

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

VIDEO CD

1-26
1-27
1-27
1-28

No.20880

Nov. 2000

MX-J270V

Safety Precautions

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

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

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

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

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

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

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

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

0.15 F AC TYPE

1500 10W

Good earth ground

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

Place this
probe on
each exposed
metal part.

Warning

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

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

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

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

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

Burrs formed during molding may be left over on some parts of the chassis. Therefore,
pay attention to such burrs in the case of preforming repair of this system.

1-2

CAUTION

!

Important for laser products

MX-J270V

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.

VARNING : Osynlig laserstrålning är denna del är öppnad

och spårren är urkopplad. Betrakta ej strålen.

VARO : Avattaessa ja suojalukitus ohitettaessa olet

alttiina näkymättömälle lasersäteilylle.Älä katso
säteeseen.

5.CAUTION : If safety switches malfunction, the laser is able
to function.

6.CAUTION : Use of controls, adjustments or performance of
procedures other than those specified herein may result in
hazardous radiation exposure.

CAUTION

!

Please use enough caution not to
see the beam directly or touch it
in case of an adjustment or operation
check.

ADVARSEL : Usynlig laserstråling ved åbning , når

sikkerhedsafbrydere er ude af funktion. Undgå
udsættelse for stråling.

ADVARSEL : Usynlig laserstråling ved åpning,når

sikkerhetsbryteren er avslott. unngå utsettelse
for stråling.

REPRODUCTION AND POSITION OF LABELS

WARNING LABEL

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

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

CLASS 1
LASER PRODUCT

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

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

1-3

MX-J270V

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

1-4

MX-J270V

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

Remove the two screws B on both sides of the body.
Remove the metal cover from the body while lifting

up the rear part of the metal cover.

1.

2.

3.

<Main body>

Removing the metal cover

(See Fig.1 to 3)

Disassembly method

Fig.3

Fig.2

Fig.1

Metal cover

A

A

A

Metal cover

B

Metal cover

B

1-5

MX-J270V

Removing the CD changer mechanism
assembly (See Fig.4 to 7)

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

1.

Disconnect the card wire from connector CN308 and
CN309 connecting the CD servo board and the main
board.

2.

Disconnect the harness from CN310 on the main
board.

3.

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

4.

Remove the plastic rivet a fixing the main board to
the front panel assembly on the left side of the body.

5.

Remove the two screws D from the rear panel.

6.

Cut off the band b and band c which bundle two
harnesses coming from the MIC/headphone board
and one harness coming from the video board,
respectively.

CD changer
mechanism
assembly

Plastic rivet a

Front panel

assembly

Main board

CN303

C

Fig.4

CD changer mechanism assembly

CN310

CN308

Rear panel

7.

Detach upward the rear part of the CD changer
mechanism assembly while pulling the front panel
assembly and the rear panel outward, then pull out
the front part backward and upward.

Rear panel

CN309

Main board

Fig.5

D

Rear panel

Fig.6

CD changer mechanism

assembly

Front panel
assembly

1-6

Pull outward

Band b

Band c

Fig.7

Pull outward

Main board

MX-J270V

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

Disconnect the card wires from connector CN302,
CN306, CN307 and the harness from CN301,
CN305 on the inside of the main board.

Turn over the body and remove the four screws E.
Release the joint d and e on both sides of the body

using a screwdriver, and detach the front panel
assembly toward the front.

1.

2.

3.

Removing the front panel assembly

(See Fig.8 to 11)

Fig.9

Fig.8

Fig.10

Fig.11

Main board

CN301

CN302

CN306

CN307

CN312

CN305

E

Front panel
assembly

Front panel
assembly

Joint d

Front panel
assembly

Joint e

(Bottom)

1-7

MX-J270V

Removing the rear cover, the rear panel,
the voltage selector and the video board
(See Fig.12 to 15)

Prior to performing the following procedures, remove
the metal cover and the CD changer mechanism
assembly.
It is not necessary to remove the front panel
assembly.

1.

Remove the two screws F and the rear cover on the
back of the body.

2.

Remove the four screws G and the seven screws H
attaching the main board and the heat sink to the
rear panel.

3.

Remove the screw I attaching the rear panel to the
chassis base.

4.

Remove the two screws J attaching the rear panel to
the voltage selector.

5.

Remove the two screws K attaching the rear panel to
the video board.

F

Rear cover

H

G

(To Earth bracket)

H

Rear panel

F

Fig.12

Rear panel

J

K

6.

Release the lower two joints f and g on both sides of
the rear panel using a screwdriver and detach the
rear panel backwards.

Rear panel

G

I

Fig.13

Joint f

Fig.14

1-8

Rear panel

Joint g

Fig.15

MX-J270V

Prior to performing the following procedures, remove
the metal cover, the CD changer mechanism
assembly, the rear cover, the rear panel, the voltage
selector and the video board.
It is not necessary to remove the front panel
assembly.

Disconnect the card wires from connector CN302,
CN306, CN307 and the harnesses from CN301,
CN305, CN901A and CN901B on the inside of the
main board.

Disconnect the harness from CN312 on the video
board.

From the right side of the body, remove the screw M
attaching the main board to the chassis base.

1.

2.

3.

Removing the main board

(See Fig.16 to 19)

Prior to performing the following procedure, remove
the rear cover, rear panel, voltage selector and the
video board.

Remove the two screws N attaching the heat sink to
the main board. Remove the IC bracket 1 and 2 on
the back of the heat sink.

Pull out the heat sink toward you.

1.

2.

~To remove the heat sink from

the main board~

Prior to performing the following procedures, remove
the main board.

Release the two joints h and i using a screwdriver
and detach the DSP board toward you.

1.

Removing the DSP board

(See Fig.19)

Fig.16

Fig.17

M

Main board

Main board

CN306

CN307

CN302

CN305

CN301

CN901A,CN901B

Fig.18

Heat sink

N

Main board

Fig.19

Heat sink

IC bracket 2

IC bracket 1

CN312

DSP board

DSP board

Joint i

Joint h

DSP board

Video board

1-9

MX-J270V

Removing the power transformer
assembly
(See Fig.20 to 22)

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

1.

Disconnect the harness from connector CN901A and
CN901B on the inside of the main board.

2.

Cut off the tie band j of the power transformer
assembly and unsolder the power cord.
(Make sure to bundle the wires after repair.)

3.

Remove the four screws O attaching the power
transformer assembly.

When removing the power transformer assembly
with the power cord, remove the rear panel and pull
out the power cord stopper from the bottom chassis
upward.

CN901A,CN901B

Video board

Voltage selector board

Power transformer assembly

Fig.20

O

Voltage selector board

Front panel

assembly

Voltage selector board

Video board

Tie band j

Rear panel

Power cord stopper

O

Fig.21

Power transformer

Fig.22

Power transformer

assembly

assembly

1-10

MX-J270V

<Front panel assembly>

Removing the MIC/headphone board
(See Fig.23 and 24)

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

1.

Remove the two screws P attaching the MIC
/headphone board.

2.

Pull out the MIC LEVEL knob from front side.

Removing the cassette mechanism
assembly
(See Fig.25)

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

1.

Disconnect the card wire from connector CN305 on
the cassette amplifier board.

2.

Remove the eight screws Q attaching the cassette
mechanism assembly.

3.

Detach the cassette mechanism assembly toward
you.

Removing the cassette amplifier board

(See Fig.26)

Fig.23

Cassette
mechanism
assembly

Q

MIC/headphone board

Front panel assembly

P

MIC LEVEL knob

Fig.24

Front panel assembly

CN305

Q

Q

Prior to performing the following procedure, remove
the cassette mechanism assembly.

1.

Disconnect the card wire from connector CN301 and
CN302 on the cassette amplifier board.

2.

Remove the six screws R attaching the cassette
amplifier board.

3.

Unsolder the soldering k on the harness for the DC
motor.

4.

Detach the cassette amplifier board toward you.

Q

Cassette amplifier board

DC motor

R

Soldering k

CN302

R

Q

R

Q

Fig.25

Fig.26

Cassette amplifier
board

Cassette mechanism

board

R

CN301

R

R

1-11

MX-J270V

Removing the display board and the
bracket (See Fig.27 and 28)

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

Disconnect the card wire from connector CN306 on

1.
the cassette amplifier board.

Remove the four screws S attaching the front panel

2.
assembly.

Remove the four screws T attaching the front panel

3.
assembly.

Unsolder FW701, FW702, FW703, FW704 and

4.
FW705 on the display board. Disconnect the
harnesses extending from the power switch board,
the eject switch board, the volume board and the
multi-control board respectively

Removing each board in the front panel
assembly (See Fig.29 to 31)

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

~Removing the multi-control board~
(See Fig.29)

1.

Remove the eight screws U attaching the multi­control board.

~Removing the volume board~
(See Fig.30 and 31)

1.

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

2.

Unhook the two hooks l on the back of the front
panel assembly and detach the volume board.

~Removing the eject switch board ~
(See Fig.29)

Remove the four screws V attaching the eject switch

1.

board.

~Removing the power switch board~
(See Fig.29)

Remove the three screws W attaching the power

1.

switch board.

Front panel

assembly

Bracket

Display board

FW703

FW701

T

Display board

Eject

switch

board

Volume

board

U

U

V

T

S

Fig.27

Fig.28

U

Front panel assembly

Front panel assembly

FW702

T

FW704
FW705

W

Power

switch

board

Multi-

control

board

U

U

1-12

Fig.30

Volume

knob

Volume

board

Fig.31

Hooks l

Front panel assembly

U

Fig.29

CD Traverse Mechanism Type:C3CN Section

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

1.

Remove the Metal cover.

2.

Remove the CD Traverse mechanism assembly.

3.

From bottom side the CD Traverse mechanism
assembly, remove the one screw A retaining the CD
Servo control board.
From the connectors CN601, CN603, CN604 on the CD

4.
Servo control board, disconnect the card wire, from the
connector CN602, disconnect the six pin connector
wire.
Disengage the two engagements "a" , remove the CD

5.
Servo control board.

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

Remove the front panel assembly.

1.
Remove the CD Traverse mechanism assembly.

2.
Remove the CD Servo control board.

3.
Remove the screw B retaining the disc stopper

4.
(See Fig.3).
Remove the three screws C retaining the T.bracket

5.
(See Fig.3).
From the clamper base section "c" , remove both of the

6.
edges fixing the rod(See Fig.2 and 3).
Remove the screw D retaining the clamper assembly

7.
(See Fig.3).
From the left side face of the chassis assembly, remove

8.
the one screw E retaining both of the return spring and
lock lever(See Fig. 4).
By removing the pawl at the section "d" fixing the return

9.
spring, dismount the return spring(See Fig.4).
Remove the three lock levers(See Fig.4).

10.

Disc stopper

T.Braket

MX-J270V

A

CD servo control board

CN604

CN
602

CN603

CN601

a

a

Fig.1

Clamper base

b

Rod

c

T.Braket

Fig.2

d

C

b

c

Clamper ass'y

B

C

Lod stopper
(C/J version only)

Return spring

C

D

E

Lock lever

Fig.4

Fig.3

1-13

MX-J270V

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 Traverse 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
stoppend, 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

CD tray assembly

g

f

Drive unit of elevator

Fig.7Fig.6

CD tray assembly

1-14

Motor pulley

Fig.8

Pawl ,

g

Fig.9

g'

MX-J270V

Removing the CD 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
mechanism assembly to the position shown in Fig.10.
Remove the four screw F retaining the CD mechanism
assembly.

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

For dismounting only the CD mechanism without

1.
removing the CD mechanism assembly, align the shaft
"j" of the CD 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 mechanism assembly in the arrow

2.
direction "l" , remove the assembly from the lifter unit
(See Fig.12).

Cam R1, R2 assembly

Cams R1, R2 assembly

Arrow

h

i

F

F

CD mechanism assembly

F

F

Fig.10

CD mechanism

Arrow

k

j

Fig.11

Removing the CD pick unit
(See Fig.13 )

Move the cam gear in the arrow direction m . Then, the

1.
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 mechanism

Shaft

Cam gear

l

1-15

MX-J270V

Removing the actuator motor board
(See Fig.14, 15)

Absorb the four soldered positions "q" of the right and

1.
left motors with a soldering absorber(See Fig.14).
Remove the two screws G retaining the actuator motor

2.
board(See Fig.14).
Remove the two screws H retaining the tray select

3.
switch board(See Fig.15).

Removing the cam unit
(See Fig.15 to 18 )

1.

Remove the CD mechanism assembly.

2.

While turning the cam gear r, align the pawl "s" position
of the drive unit to the notch position(Fig.15) on the cam
gear r.
Pull out the drive unit and cylinder gear(See Fig.17).

3.
While turning the cam gear r, align the pawl "t" position

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

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

Motor L

G

Motor R

q

q

G

Actuator motor board

Fig.14

Chassis assembly

CN801

Fig.15

CN802

Drive unit

Tray select
switch board

Cylinder gear

CN804

Drive unit

s

H

Cam gear L

I

Cam gear r

Fig.16

I

Cams R1, R2 assembly

Cam unit

I

1-16

Fig.17

t

Select lever

Fig.18

MX-J270V

Removing the actuator motor and belt
(See Fig.19 to 22)

1.

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

2.

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

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

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

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

[Note]

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

Pully gear

Gear bracket

Belt

Motor pulley

J

Fig.19

Actuator motor

Pulley gear
Belt
Motor pulley

J

Pawl

u

Chassis assembly

v

Gear bracket

Fig.20

Assembly and Configuration Diagram

Pulley gear

w

w

Fig.21

Pulley gear

Gear B

Cylinder gear

Gear B

Gear C

Select gear

Gross gear L

Fig.22

Gross gear U

Gear C

1-17

MX-J270V

Removing the cams R1/R2 assembly
and cam gear r (See Fig.23)

Remove the slit washer fixing the cams R1 and R2

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

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

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

4.

Slit washer

Cam gear r

Removing the C.G. base assembly
(See Fig.23 and 24)

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

[Caution]

To retassemble 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 "s" on the drive unit to that o f the notch
on the cam gear r. Then, make sure that the
gear unit is engaged by turning the cam gear r
(See Fig. 24).

K

Slit washer
Cam R2

Pawl

Cam R1

x

Cam switch board

C.G. base assembly

Pawl

x

Notch

Pawl

s

Cylinder
gear

Drive unit

Fig.23

Cam gear r

Cam R1, R2 assembly

Gear unit

Gear bracket

Fig.24

1-18

MX-J270V

< Cassette mechanism section >

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

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

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

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

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

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

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

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

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

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

Reassembling the playback, recording
and eraser heads (See Fig.2,3)

Cassette mechanism

Fig.1

Playback/Recording &
eraser head

Flexible
P.C.board

CN301

Head amplifier & mechanism
control P.C. board

Fig.2

Flywheel R

Trigger armHead mount

(Mechanism A side)

Spring "a"

Trigger arm

Flywheel R

(Mechanism A side)

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

2. Fix the reversing azimuth screw.

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

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

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

Playback head

Spring "a"

FPC holder

Fig.3

Reversing azimuth
screw

Head
mount

Flexible
P.C.board

CN302

Head amplifier &
mechanism control
P.C. board

(Mechanism B side)

1-19