JVC MX-GA3V Service Manual
SERVICE MANUAL
COMPACT COMPONENT SYSTEM
MX-GA3V
MX-GA3V
SP-MXGA3V CA-MXGA3V SP-MXGA3V
Contents
Safety precautions ---------------------------- 1- 2
Important for laser products ----------------- 1- 3
Preventing static electricity ----------------- 1- 4
Disassembly method ------------------------ 1- 5
Adjustment method -------------------------- 1- 18
Area Suffix
US ................... SINGAPORE
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
Wiring connection ----------------------------- 1- 29
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LTD.
No. MB036
2003/11
MX-GA3V
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.
Safety Precautions
!
) on the Parts List in the Service Manual. The use of a substitute replacement
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.).
0.15 F AC TYPE
1500 10W
AC VOLTMETER
(Having 1000
ohms/v
olts,
or more sensitivity)
Place this
probe on
each exposed
metal part.
1-2
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.
Important for laser products
MX-GA3V
1. CLASS 1 LASER PRODUCT
2. CAUTION :
Visible and invisible laser radiation when
open and interlock 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.
VAR O :
Avattaessa ja suojalukitus ohitettaessa olet
alttiina näkymättömälle lasersäteilylle. Älä
katso säteeseen.
REPRODUCTION AND POSITION OF LABELS
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 :
ADVARSEL :
Usynlig laserstråling ved åbning, når
sikkerhedsafbrydere er ude af funktion.
Undgå udsættelse for stråling.
Usynlig laserstråling ved å pning, når
sikkerhetsbryteren er avslott. Unngå
utsettelse for stråling.
VIDEO OUT
WARNING LABEL
V
220
110V
230V
127V
-240
V
1-3
MX-GA3V
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
CD changer
unit
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
CD changer
mechanism
assembly
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.1 and Fig.2.
(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.2
Fig.1
Soldering
1-4
MX-GA3V
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
Chassis unit
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 cassette deck mechanism
Removing the earphone jack PCB
Removing the control/FL PCB
Removing the switch PCB and ACTIVE BASS EX. switch PCB
Removing the cassette deck main motor, and replacing the main belts
Removing the leaf switches of the cassette deck mechanism
Removing the cassette deck heads
Chassis unit
Removing the 3-pin regulator
Removing the power amp and supply PCB and the Power Trans PCB
Removing the sub power PCB
1-5
MX-GA3V
<Disassembly of the main blocks of the set>
Replacement of the fuses and the power IC
Replacing the fuses (See Fig.1, Fig.3)
Prior to performing the following procedure, remove
the left side BOARD and remove tuner PCB
(Fig.3,BB)
1. Replace the fuses inside.
[Caution]
Be sure to use fuses with the specified ratings.
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.
2. Remove the solder fixing the power IC.
Bottom side Fig.1(A)
Fuse(F952)
CN951
T1.6AL 250V
Component side Fig.1(B1)
Fuse(F951)
T2AL 250V
Add Lable
T2AL 250V
Add Lable
T1.25AL 250V
Fuse(F953)
T1.25AL 250V
Fig.2
WA
Replacing the heat sink cover (See Fig.3)
1. Remove four screws B from the rear panel.
2. Pull the heat sink cover outward.
Fig.3
1-6
Fuse(F953)
T1.25AL 250V
Component side Fig.1(B2)
Fuse(F951)
T2AL 250V
Add Lable
T1.25AL 250V
Fuse(F952)
T1.6AL 250V
VIDEO OUT
BB
V
220
110V
230V
127V
-240
V
B
Removing the top cover
(See Fig.4 and 5)
1. Remove six screws B that retain the top cover from
the panel rear of the body.
Remove eight screws C and D that retain the top
2.
cover from the two sides of the body.
3. Remove the top cover from the body by lifting it
toward the rear.
Fig.4
Top cover
B
VIDEO OUT
MX-GA3V
2
23
-2
C
C
Fig.5 (A) Fig.5 (B)
Right Front panel assembly
Left Front panel assembly
DD
1-7
MX-GA3V
Removing the CD changer unit
Prior to performing the following procedures, remove
the top cover and both sides BOARD.
(See Fig.6 to 9)
[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 CD PCB CN704,
CN607, CN1101 and disconnect CN1 (shield wire)
from back panel.
2.
From the rear of the set, remove two screws E and
two 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
Accessory
terminal
Fig.7
E
F
Antenna
termianl
F
Fig.6
Fig.8
CD changer
unit
G
1-8
Fig.10
Removing the front panel assembly
(See Fig.10 to 11)
Prior to performing the following procedures, remove
the top cover and both board.
Also remove the CD changer unit.
1. Disconnect the parallel wire and the cord wire from
the connectors CN701, CN702, CN703, CN850 on
the power amp. and supply PCB.
H
2. Remove two screws
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
amp and supply PCB.
retaining the front panel
b
that comes from the power
MX-GA3V
4. Disengage the claws
c
on both sides of the front
panel assembly and then remove the assembly.
Claw
c
H
Fig.10
Power amp and
supply PCB
GND lug
I
b
Fig.12
1-9
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