JVC SP-MXGT90, CA-MXGT90 Service Manual

SERVICE MANUAL

COMPACT COMPONENT SYSTEM

MX-GT90

Area Suffix

US
UW
UY

Brazil,Mexico,Peru

MX-GT90

Singapore

Argentina

SP-MXGT90

(No MIC jack and MIC LEVEL volume for UY ver.)

Contents

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

STANDBY/ON

STANDBY

CD-R/RW PLAYBACK

CA-MXGT90

1-2
1-3
1-4
1-5
1-25

PLAY & EXCHANGE

MX-GT90

SP-MXGT90

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

1-29
1-30
1-30
1-31~50

COPYRIGHT 2001 VICTOR COMPANY OF JAPAN, LTD.

No.20996

Jun. 2001

MX-GT90

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 circuitr y of the product should not be made. Any design alterations of the product
should not be made. Any design alterations or additions will void the manufacturer's warranty and will further
relieve the manufacture of responsibility for personal injury or property damage resulting therefrom.

3. Many electrical and mechanical parts in the products have special safety-related characteristics. These

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

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

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

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

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

0.15 F AC TYPE

1500 10W

Good earth ground

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

Place this
probe on
each exposed
metal part.

!

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

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

3. Repairs m ust 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 v oltage.

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 pr inted 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 JC version)

1-2

Important for laser products

MX-GT90

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.

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.

POSITION OF LABELS

CLASS 1
LASER PRODUCT

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)

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-GT90

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

MX-GT90

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

A

Metal cover

Metal cover

A

Fig.1

B

Fig.2

Metal cover

B

Fig.3

1-5

MX-GT90

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

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

1.

Disconnect the card wire from connector CN561 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. it is assembly to remove the fan's card
wire.

Front panel assembly

C

Main board

CN561

Fig.4

CD changer mechanism assembly

Main board

CN561

C

CD changer
mechanism assembly

Rear panel

Rear panel

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.

D

Plastic rivet

Front panel assembly

Fig.5

1-6

MX-GT90

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.

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.

Amplifier board

CN703

CN705

Transformer board

CN220

Tie band

Fig.6

Main board

CN870

CN871

CN315

Front panel
assembly

Front panel assembly

Fig.9

Joint a

Front panel assembly

Front panel assembly

Fig.7

Main board

E

(Bottom)

Fig.8

Joint a

Front panel assembly

Fig.10

1-7

MX-GT90

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 ten screws H and two screws H' (US,
UW only) 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.22)

F

H
H

Rear cover

Fig.12

Rear panel

(US,UW only)

H'

H

Joint c

1-8

Rear panel

Fig.15

Rear panel

Fig.14

Joint c

MX-GT90

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 I 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.

CN871

CN315

Amplifier board

CN704,CN706

Front panel assembly

Main board

CN870

Fig.16

Plastic rivet

Front panel assembly

Main board

Removing the speaker terminal 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
terminal board from the regulator board.

It is not necessary to remove the main
board.

Regulator board

Regulator board

I

Fig.17

Fig.18

CN212

CN211

Speaker terminal board

CN217

1-9

MX-GT90

Removing the voltage selector board
(See Fig. 19)

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 CN218, CN219
and CN250 on the voltage selector board
respectively.

2.

Remove the two tie band attaching the wire to the
voltage selector board.

3.

Disconnect connector CN213 on the voltage selector
board from the regulator board.

Removing the amplifier board / voltage
board / heat sink (See Fig.20 and 21)

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

1.

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

Voltage selector board

CN213

Amplifier board

CN704
CN706

Voltage

board

Regulator

board

Tie band

Tie band

Fig.19

CN218

CN219

Tie band

CN703

CN215

2.

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

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 J attaching the amplifier
board to the heat sink.

6.

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

K

J

Fig.21

Fig.20

J

Amplifier board

CN216

Heat sink

Voltage board

1-10

MX-GT90

Removing the power transformer
assembly (See Fig.22 and 23)

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 CN218 and
CN219 on the voltage selector board.

2.

Remove the two tie band from the voltage s

elector

board.

3.

Disconnect the wire from connector CN204 on the
regulator board.

4.

Remove the plastic holder.

5.

Remove the four screws L attaching the transformer
assembly.

Removing the regulator board

(See Fig.23)

Voltage selector

board

Power cord

stopper

Power cord

Base chassis

Regulator board

CN204

Tie band

CN219

CN250

Fig.22

Transformer board CN220

CN218

Power transformer

assembly

L

Transformer

board

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

1.

Disconnect the wire from connector CN204 on the
regulator board.

2.

Remove the two screws M attaching the regulator
board.

Removing the power cord (See Fig.24)

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

1.

Disconnect the power cord from connector CN250
on the v

2.

Remove the tie band from the voltage s

3.

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

oltage selector board.

elector board.

Plastic

holder

Regulator board

Voltage selector board

CN219

Power cord

stopper

Fig.23

CN218

M

Power transformer assembly

Power
transformer
assembly

L

Power cord

Tie band

Fig.24

CN250

1-11

MX-GT90

<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.25)

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.26 to 28)

1.

Remove the four screws O 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

N

N'

Cassette mechanism
assembly

N

N

N'

N'

Fig.25

O

3.

Remove the seven screws P 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. 29)

Removing the CD eject board

(See Fig.28 and 29)

1.

Remove the three screws Q attaching the CD eject
board.

2.

If necessary, unsolder FW915 on the CD eject
board.

CD eject board

FW915

(Soldering)

Q

Q

Display system control board

P

FW915

(Soldering)

P

CN880

P

Stay bracket

Fig.26

CN316

Display system control board

Fig.27

CD eject board

CN911

P

P

FW915

FW915

Fig.29

1-12

Display system control board

Fig.28

MX-GT90

Removing the preset / tuning switch
board (See Fig.30 and 31)

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 R attaching the preset /
tuning switch board.

Removing the operation switch board

(See Fig.31 and 32)

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 SOUND MODE knob
and the SUB WOOFER level knob MIC LEVEL
volume knob(Only US, UW) toward the front.

R

PRESET knob

Preset / tuning switch board

R

Fig.30

SOUND MODE knob

SUB WOOFER
level knob

2.

Remove the twelve screws S and the screw S' (Only
US, UW) attaching the operation switch board.

3.

Release the wire clamp.

4.

Remove the screw T attaching the earth terminal
extending from the switch board.

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

VOLUME knob

Joint g

Joint g

S'

(US,UW only)

S

S

Joints g

Nut

MIC LEVEL
volume knob

(US,UW only)

Fig.31

S

Operation
switch board

Joint g

Wire clamp

S

Joints g

S

Fig.32

S

S

T

1-13

MX-GT90

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.

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

Rod

A

T.Braket

Fig.1

Fig.2

B

CC

A

Clamper base

d

Earth

wire

c

a

b

Clamper ass'y

1-14

Fig.3

B'

Lod stopper
(C/J version only)

C
D

Return spring

E

Lock lever

Fig.4

MX-GT90

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.

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

Chassis assembly

Refer to Fig.7

Pawl

Fig.6

CD tray assembly

g

CD
CD

CD

f

Drive unit of elevator

Fig.7

3
2

1

CD tray assembly

Pulley gear

Motor pulley

Fig.8

Pawl ,

g

Fig.9

g'

1-15

MX-GT90

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 )

1.

For dismounting only the CD traverse mechanism
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

Arrow

k

Cams R1, R2 assembly

Arrow

h

i

F

F

CD loading mechanism assembly

Fig.10

F

F

CD traverse mechanism

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

1-16