JVC MXGC-5 Service manual

SERVICE MANUAL

COMPACT COMPONENT SYSTEM

MX-GC5

MX-GC5

SP-MXGC

5

CA-MXGC

Contents

Safety precautions ---------------------------- 1- 2
Preventing static electricity ----------------- 1- 3
Important for laser products ---------------- 1- 4
Disassembly method ------------------------ 1- 5
Adjustment method -------------------------- 1- 18

COPYRIGHT © 2005 Victor Company of Japan,Limited

5

Flow of functional
operation until TOC read -------------- 1- 20
Maintenance of laser pickup -------------- 1- 21
Replacement of laser pickup -------------- 1- 21
Description of major ICs ------------------- 1- 22

SP-MXGC

5

Area Suffix

J ........................ U.S.A.

C ........................ Canada

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 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 (
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 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 AC­type 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 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.).

! ) on the Parts List in the Service Manual. The use of a substitute replacement

AC VOLTMETER
(Having 1000
ohms/v

olts,

or more sensitivity)

0.15 F AC TYPE

Place this
probe on

1500 10W

each exposed
metal part.

Good earth ground

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.

!

CAUTION

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.

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 testers internal power
source can easily destroy the laser diode.

4. Handling the CD changer unit (optical pickup)

1. Do not subject the CD changer 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 CD changer
unit. Be careful not to take too long a time when attaching it
to the connector.

CD changer

unit

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 changer mechanism.

1. Remove the CD changer unit.

2. Disconnect the harness from connector on the CD motor
board.

3. Solder is put up before the card wire is removed from connector
Cn601on the main board as shown in Fig.A and Fig. B.
(When the wire is removed without putting up solder, the
CD pick-up assembly might destroy.)

4. Please remove solder after connecting the card wire with
CN601 when you install picking up in the substrate.

Flexible cable

Fig.A

Soldering

Fig.B

Important for laser products

1. CLASS 1 LASER PRODUCT

2. DANGER :

lock failed or defeated. Avoid direct exposure to beam.

3. CAUTION :

Laser Unit. Do not disassemble the Laser Unit. Replace
the complete Laser Unit if it malfunctions.

4. CAUTION :

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.

Invisible laser radiation when open and inter

There are no serviceable parts inside the

The compact disc player uses invisible

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

6. CAUTION :

of procedures other than those specified herein may
result in hazardous radiation exposure.

!

CAUTION Please use enough caution not

Use of controls, adjustments or performance

to see the beam directly or touch
it in case of an adjustment or
operation check.

FUSE CAUTION

CAUTION:

REPLACE WITH SAME TYPE
AND RATING FUSE (S).

ATTENTION:

REMPLACER PAR UN(LES)
FUSIBLE(S) DE MEME TYPE
ET DE MEME VALEUR

Disassembly method

Commence disassembly of the set by removing the main units and then proceed to the components
and assemblies inside the units.

Replacement of the fuses and the power IC

 Top cover

 CD changer unit

 Front panel assembly

 CD changer unit

 Removing the main PCB
 Removing the CD changer mechanism assembly
 Removing the CD pickup
 Replacing the loading motor and belt of the CD changer tray
 Replacing the CD tray rotor belt of CD changer, and removing the motor

 Front panel assembly

 Removing the (USB, AUX jack) earphone jack PCB
 Removing the control/FL PCB
 Removing the volume, preset and CD Function switch PCB
 Removing the remote sensor PCB
 Removing the standby Led PCB
 Removing jack Led backlight PCB
 Removing Sound mode PCB

1-5

<Disassembly of the main blocks of the set>

Replacement of the fuses and the power IC



Replacing the fuses (See Fig.1)



Prior to performing the following procedure, remove

the left side BOARD.

1. Replace the fuses inside.



Replacing the heat sink cover (See Fig.3)

1. Remove four screws B from the rear panel.

2. Remove four screws

E

from the heat cover.

3. Pull the heat sink cover outward.

[Caution]

Be sure to use fuses with the specified

ratings.

Fuse (F901)

Fuse (F902)

1.6A 250V

3.5A 125V

Fig.1



Replacing the power IC (See Fig.2)



Prior to performing the following procedure, remove

the top cover.

1. Remove the two screws A from the heat sink between
the power IC(STK412-430)

2. Remove the four screws B from the heat sink the
between the power IC (D1889,B1340)

3. Remove the solder fixing the power IC.

E

B

Fig.3

AA

Fig.2

B



Top cover

C

Removing the top cover

(See Fig.4 and 5)

1. Remove six screws C that retain the top cover from
the panel rear of the body.

2.

Remove six screws D that retain the top cover from

the two sides of the body.

3. Remove the top cover from the body by lifting it

toward the rear.

Fig.4

Right Front panel assembly Left Front panel assembly

D

D D

D

Fig.5



Removing the CD changer unit

(See Fig.6 to 9)



Prior to performing the following procedures, remove

the top cover.

[Caution]

Although the CD mechanism unit can be

removed without removing the CD tray
panel, it is still recommended to remove it
in order to prevent damage.

a. From the front panel side of this set, push in the

sections marked with arrows and pull out the CD
tray toward the front.

b. Remove the CD tray panel by pushing both of

its extremities upward in the direction of the
arrows.

c. Push the CD tray deep into the set.

1.Disconnect the cord wires from the main PCB
CN401,CN601,CN501 and CN203.

2. From the rear of the set, remove two screws E, two

screws F and four screws G on the front panel left
and right side.

3. Handle the CD changer unit rear, take out the unit.

CD tray panel

CD tray panel

Fig.7

E

F

Antenna
terminal

F

Fig.6

Fig.8

G

Fig.9



Removing the front panel assembly

(See Fig.10 to 11)



Prior to performing the following procedures, remove

the top cover.



Also remove the CD changer unit.

1. Disconnect the parallel wire and the cord wire from
the connectors CN201, CN401 on the main PCB.

2. Remove one screws H retaining the front panel
assembly onto the bottom of the body.

3. Remove two screws I on the left and right side of the set
retaining the panel front from the bottom and then
remove then GND lug b that comes from the power
amp and supply PCB.

4. Disengage the claws c on both sides of the front
panel assembly and then remove the assembly.

Fig.10

H

Fig.11

GND lug

Claw

b

c

<Disassembly of units and assembly
inside this set>



Removing the MAIN PCB

(See Fig.12 to 13)



Prior to performing the following procedures, remove

the top cover.



Also remove the CD changer unit.

1. Disconnect the wires from CN701, CN702 and

CN703 on the CD PACK PCB, which is located on
the down side of the CD changer unit.

2. The four screws J that retain the CD PCB should

be removed.

3. Remove the CD PCB by pulling it toward the side

where the CN701 is located.

4. Using solder, short the CD pickup to connect to

short round.

J

CD PCB

J

Fig.12

J

[Caution]

After re-connecting the wires, be sure to

remove the shorting solder from the GND
connection.

5. Disconnect the card wire from the connector CN701

on the main PCB and then remove the main PCB.

CD PCB

CN601

Short round

Fig.13



Removing the CD changer mechanism

assembly (See Fig.14 to 15)



Prior to performing the following procedures, remove

the top cover.



Also remove the CD changer unit.

1. Turn the CD changer mechanism cover base and
remove the screws d connecting the unit to the CD
changer mechanism assembly.

2. Removing four screws e retaining the CD mechanism
holder assembly.

CD changer
unit

[Caution]

CD changer
mechanism

assemb

ly

When replacing the CD changer mechanism

assembly, be sure not to mistake the positions
of the silver color and copper color spring.

e

e

( Green color )

( Red color )

d

Fig.14

e

( Green color )

Fig.15

e

( Red color )



Removing the CD pickup (See Fig.16)



Prior to performing the following procedures, remove

the top cover.



Also remove the CD changer unit.



Also remove the CD changer mechanism.

f

1. Widen the section

.

2. While keeping the section f wide open, push the
section g in the direction of the arrow to remove
the shaft, and then remove the CD pickup.



Replacing the loading motor and rotor
belt of the CD changer (See Fig .17)



Prior to performing the following procedures, remove

the top cover.



Also open the CD changer tray.

CD pickup

f

Shaft

g

1. Remove the two screws L retaining the CD changer
tray loading motor.

2. Remove the two screws M retaining the gear plate
and take it out, after remove the rotor belt from the
pulley.



Replacing the CD turn table and remov-

ing the motor (See Fig. 18 )



Prior to performing the following procedures, remove

the top cover.



Also remove the CD changer unit.

N

1. Remove the one screws
table).

2. Remove the two screws O retaining the stopper

brackets on both sides of the CD changer unit.

3. Remove the stopper brackets from both sides of

the CD changer unit.

4. Pull out the CD tray from the CD changer unit, all
the way and lift the tray (u/~ ward) to remove.

5. Remove the gear and after push out the tray motor
locker and pull out the tray motor from the CD tray.

retaining the CD (Turn

Fig.16

M

L

Fig.17

Turn table motor

, and then remove the CD tray

Fig.18

Motor locker

Obligue gear



Removing the USB,AUX,earphone PCB

(See Fig.19)



Prior to performing the following procedures, remove

the top cover.



Also remove the CD changer unit.



Also remove the front panel assembly.

Remove six screws

earphone PCB.

Z

retaining the USB,AUX,

Front panel
assembly

R( 17PCS)

S

T

Z

Fig.19

Q



Removing the remote sensor PCB & the
standby PCB

(See Fig.20)



Prior to performing the following procedures, remove

the top cover.



Also remove the CD changer unit.



Also remove the front panel assembly.

1. Remove four screws

P

that retains the

remote sensor PCB.

L

2. Remove four screws

that retains the

standby Led PCB.



Removing the display PCB

(See Fig.21)



Prior to performing the following procedures, remove

the top cover.



Also remove the CD changer unit.



Also remove the front panel assembly.

Remote sensor
PCB

P

Display PCB

Q

Fig.20

Front panel
assembly

Standby Led

L

PCB

Q

1. Remove four screws Q that retain the display PCB
from the back of the front panel unit.

Fig.21



Removing sound mode and volume , pre-

set and CD function switch PCB

(See Fig.20 to 23)



Prior to performing the following procedures, remove

the top cover.



Also remove the CD changer unit.



Also remove the front panel assembly.

1. Pull out the volume control knob from the front of
the front panel assembly.(Fig.22)

2. Pull out the preset knob from the front of the front
panel assembly (Fig.22)

3. Remove four screws Q retaining the front panel
assembly.

4. Remove the control/FL PCB.

5. Remove eight screws S retaining the sound mode
switch PCB.(Fig.21)

6. Remove seventeen screws R retaining the volume ,
preset and CD founction switch PCB.(Fig.20)

7. Remove two screws T retaining the jack Led
Backlight PCB.

Front panel assembly

Preset Knob

Volume knob

Fig.22

Preset shaft

Front panel
assembly

Volume
shaft

Fig.23



Removing the bridge diode

(See D214, D215 and Fig.28)



Prior to performing the following procedures, remove

the top cover and both sides board.

1. Remove two screws W that connect the heat sink.

2. Remove the solder fixing the 4-pin bridge diode
(D214, D215).



Removing the power amp and supply PCB

and the power trans PCB

(See Fig. 2, 29 to 31)



Prior to performing the following procedures, remove

the top cover and CD changer unit.

1. Remove four screws B from the rear panel. (Fig.3)

2. Pull the heat sink cover outward.

3. Remove four screws

the heat sink holder.

4. Remove four screws

and then remove the rear panel.

5. Disconnect the parallel wires from the connectors

FW951 on the power trans PCB.

6. Remove screws Z that retain the power amp and

supply PCB and then remove the assembly.

7. Remove four screws that retain the power trans PCB

and then remove the assembly.

AA

from the rear panel between

YY

that retains the rear panel,

Fuse (F902)

1.6A 250V

Rear panel

W

Fig.28

Fuse (F901)

3.5A 125V

Fig.29

Power amp and
supply PCB

AA

Z(4PCS)

Fig.31

Clamp

YY

Fig.30

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 CN702 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 20 of
IC611(TE)

Approx

0.3V

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

pin10 of IC701 is + 0V?

Confirm that the Focus error
S-cuve signal at the pin31 of
IC701 is approx.2Vp-p

Confirm that the signal from
pin26 IC701 is 0V as a
accelerated pulse during
approx.400ms.

Confirm the waveform of
the Tracking error signal.
at the pin 29 of IC701 (R729)
(See fig-1)

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 Pin 2 of IC 701

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.

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.

Is the level of

RFOUT under

0.48V 0.1Vp-p?

YES

O.K

(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 would be adjusted when the pickup operates normally, the laser pickup may be
damaged due to excessive current.

NO

Replace it.

Play a disc.

Check the eye-pattern at

Finish.

Pin 2 of IC 701



W

W

F

F

W

W

F

F

F

F

0

0

/10V

F

/10V

0
F

F

/50V

/50V

W

W

F

F

4

5

5

r

r

5

4

9

0

8

2

8

6

5

2

4

3

7

3

4

5

6

3

4

5

6

3

4

5

6

3

4

5R16

Description of major ICs STK412-430 (IC201) : Dual low noise operational

1. Equivalent Block Diagram

1

TR41

1

R41

R

TR1

D2

TR2

1

TR

1

C2 C11

C1

R1

TR

TR

TR9

R

R

TR8

TR10

TR19

TR20

TR18

R1

TR1

D12

C12

R1

R1

TR1

R11
TR1

TR11TR12

Comparato

D

D

R

R2

TR

TR7

R7

D1

R17

TR17

TR1

R12

TR51

Comparato

R51

1

1

11

2. Test Circuit

+VH

+VL

GND

-VL

-VH

100uF
/50V

100uF
/50V

100uF
/100V

100uF
/100V

2 3 4

1

GZA
1

1.5kohm
/1

X

5

GZA

X

1

1.5kohm
/1

6

891011 12

7

*1

56kohm

3p

100ohm/1

100u
/100V

100u
/100V

100ohm/1

SUB.GND

(*1)Metal Plate Cement Resistor 0.22ohm+-10%(5W)

*1

56kohm

13

14

3p

100u

16

ohm

33kohm

56

17

100p

ohm

56

100uF

3uH

4.7ohm

4.7ohm/1

4.7ohm/1

3uH

4.7ohm

18 15

100p

2.2uF

56kohm 56kohm

2.2uF

SUB

1kohm

1kohm

0.1u

0.1u

470p

p

47

D

D52

1

Ch2 IN

GND

Ch1 IN

Ch2 OUT

GND

Ch1 OUT



CD DRIVE ICS BA5927FM(IC702)



BA4558F (IC503) : Dual low noise operational amp.

1. Terminal layout

1. Pin descriptions

OUT1

- IN1

+IN1

VEE



1chip AM/FM, MPX tuner system

+-

Vcc

OUT2

- IN2

-+

+IN2

1. Block diagram

24

FM

RF

23

GND2

22

VCC2

21

20

FM

OSC

FM

MIX

MUTE

ST SW

17 16

DECODER

VCO FF FF

TRIG

15

PHASE

COMP

14

PILOT

DET

FF

1319 18

FM

DET

AM

RF

REG VCC1 GND1

1 2 4 5 10 11 126 7 8 93

AM

MIX

AM

OSC

OSC

BUFFER

2. Pin function

Pin
No.

Symbol

I/O

1 AM_RFIN I AMRF signal input

2 REG. -

3 AM_OSC - AM local oscillation circuit

4 VCC_1 - Power supply terminal

FM_MIXOUT

5

O Output terminal for FM mixer

6 GND_1 - Ground

7

IF_BUFFER

O IF buffer output

8 ST_IND O Stereo indicator output

AM_MIXOUT

9

O Output terminal for AM mixer

10 FM_IF IN I Input of FMIF signal

11 AM_IF IN I Input of AMIF signal

12 AGC I AGC voltage input terminal

Function

FM

S-METERAMDET

FM

IF

AM

IF

Function

IF

BUFFER

Pin
No.

STSD

Symbol

I/O

13 FM_DET O FM detection signal output

ST/MON_SW

14

15

AM/FM_SW

I Stereo/Monaural switching signal input

I AM/FM switching signal input

16 L_OUT O Output L-channel

17 R_OUT O Output R-channel

18 MPX_IN I Multiplex signal input

19 DET_OUT O AM/FM detection output

20 FM_OSC - FM local oscillation circuit

21 VCC_2 - Power supply terminal

22

FM_RFOUT

O Output of FMRF signal

23 GND_2 - Ground

24 FM_RFIN I Input of FMRF signal

AGC



RHYTHM AX (IC502) JCV8011 : Block diagram