JVC MX-GA8V Service Manual
MB012200310
SERVICE MANUAL
COMPACT COMPONENT SYSTEM
MX-GA8V
COMPACT
DIGITAL VIDEO
UX ---------- Saudi Arabia
UN ------------------ Asean
U ------------- Other Areas
COMPACT
DIGITAL AUDIO
Area Suffix
TABLE OF CONTENTS
1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-35
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-39
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LIMITED
No.MB012
2003/10
SPECIFICATION
Amplifier section
Output Power SUBWOOFERS 68 W per channel, min. RMS, both channels driven into 6 Ω at 63
Hz with no more than 0.9% total harmonic distortion.
MAIN SPEAKERS 22 W per channel, min. RMS, both channels driven into 6 Ω at 1
kHz with no more than 0.9% total harmonic distortion.
Audio input sensitivity/Impedance
(Measured at 1 kHz, with tape
recording signal 300 mV)
Digital output CD OPTICAL DIGITAL OUTPUT
Signal wave length 660 nm
Output level -15 dBm to -12 dBm
Speakers/Impedance SUBWOOFERS 6 Ω - 16 Ω
FM tuning range 87.50 MHz - 108.00 MHz
AM tuning range For Saudi Arabia At 9 kHz intervals : 531 kHz - 1 602 kHz
CD capacity 3 CDs
Dynamic range 85 dB
Signal-to-noise ratio 90 dB
Wow and flutter Immeasurable
Frequency response Normal (type I) 50 Hz - 14 000 Hz
Power requirement A C 11 0 V / A C 127 V / AC 220 V / AC 230 V - AC 240 V~(adjustable w ith the voltage selector),50 Hz / 60 Hz
Power consumption 130 W (at operation) 25 W (on standby)
Dimensions (approx.) 265 mm x 335 mm x 401 mm (W/H/D) (10 7/16 in. x 13 1/4 in. x 15 13/16 in.)
Mass (approx.) 10.0 kg (22.1 lbs)
AUX 390 mV/50 kΩ
MIC 1/2 3.0 mV/5 kΩ
MAIN SPEAKERS 6 Ω - 16 Ω
SURROUND SPEAKERS 16 Ω - 32 Ω
Tuner
At 10 kHz intervals : 530 kHz - 1 600 kHz
For other countries At 9 kHz intervals : 531 kHz - 1 710 kHz
At 10 kHz intervals : 530 kHz - 1 710 kHz
CD player
Cassette deck
Wow and flutter 0.15% (WRMS)
General
1-2 (No.MB012)
SECTION 1
PRECAUTION
1.1 Safety Precautions
(1) This design of th is product contains special hardw are 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 manufacturers 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 reassembling.
(5) Leakage shock hazard testing
After reassembling 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, 1,000Ω per volt or more sensitivity
in the following manner. Connect a 1,500Ω 10W resistor
paralleled by a 0.15µF 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.).
AC VOLTMETER
(Having 1000
ohms/volts,
or more sensitivity)
0.15 F AC TYPE
Place this
probe on
1500 10W
Good earth ground
1.2 Warning
(1) This equipment has been designed and manufactured to
meet international safety standards.
(2) It is the legal resp onsibility 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 compone nts are replaced
by approved parts.
(5) If mains voltage selector is provided, check setting for local
voltage.
1.3 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.
1.4 Critical parts for safety
In regard with component parts appearing on the silk-screen
printed 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.
(This regulation dose not Except the J and C version)
each exposed
metal part.
(No.MB012)1-3
1.5 Preventing 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.
1.5.1 Grounding to prevent damage by static electricity
Static electricity in the work area can destroy the optical pickup (laser dio de) in devices such as CD players.
Be careful to use proper grounding in the area where repairs are being performed.
(1) Ground the workbench
Ground the workbench by laying conductive material (such as a conductive sh eet) or an iron plate over it before placing the
traverse unit (optical pickup) on it.
(2) Ground yourself
Use an anti-static wrist strap to release any static electricity built up in your body.
(caption)
Anti-static wrist strap
1M
Conductive material
(conductive sheet) or iron palate
(3) Handling the optical pickup
• In order to maintain quality during transport and before installation, both sides of the laser diode on the replacement optica l
pickup are shorted. After replacement, return the shorted parts to their original condition.
(Refer to the text.)
• 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.
1.6 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) I t is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not turn it.
1.7 Attention when traverse unit is decomposed *Please refer to "Disassembly method" in the text for the CD pickup unit.
• Apply solder to the short land sections before the flexible wire is disconnected from the connector on the CD servo board. (If the
flexible wire is disconnected without applying solder, the CD pickup may be destroyed by static electricity.)
• In the assembly, be sure to remove solder from the short land sections after connecting the flexible wire.
1-4 (No.MB012)
CD changer
mechanism
assembly
CD traverse
unit
Flexible cable
Soldering
1.8 Important for laser products
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 de
feated. It is dangerous to defeat the safety switches.
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.
!
Please use enough caution not to
see the beam directly or touch it
in case of an adjustment or operation
check.
REPRODUCTION AND POSITION OF LABEL and PRINT
WARNING LABEL and PRINT
CLASS 1
LASER PRODUCT
(No.MB012)1-5
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.
1-6 (No.MB012)
SECTION 3
A
A
DISASSEMBLY
3.1 Main body
3.1.1 Removing the metal cover
(See Fig.1 ~ 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.
Metal cover
A
Metal cover
B
Fig.2
Metal cover
Fig.1
B
Fig.3
(No.MB012)1-7
3.1.2 Removing the CD changer mechanism assembly
(See Fig.4 ~ 6)
• Prior to performing the following procedure, remove the metal
cover.
(1) Disconnect the wire from connector CN705 on the amplifier
board.
(2) Remove the plastic rivet attaching the main boa rd to the
front assembly on the right side of the body.
(3) Disconnect the card wire from connector CN661
main board.
(4) Remove the two screws C on the upper si de of the body
and the two screws D on the back of the rear panel.
(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.
REFERENCE:
At this point, one card wire on the underside of the CD
mechanism assembly is still connected.
(6) Disconnect the card wire from connector CN504
ner side of the main board on the right side of the body. Remove the CD mechanism 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.
CD changer mechanism assembly
Front panel assembly
on the
on the in-
Front panel assembly
C
Main board
CN661
CN504
Fig.5
CD changer mechanism assembly
Plastic rivet
Main board
CN661
CN504
C
CD changer
mechanism assembly
Rear panel
Rear panel
D
Rear panel
Amplifier board
CN705
Fig.4
3.1.3 Removing the fan
(See Fig.7)
• Prior to performing the following procedure, remove the metal
cover and the CD changer mechanism assembly.
(1) Turn over the CD changer mechanism assembly and re-
move the two screws E attaching the fan.
Front panel assembly
E
Fig.6
Fan
E
1-8 (No.MB012)
CD changer mechanism assembly
Fig.7
3.1.4 Removing the front panel assembly
A
(Bottom)
(See Fig.8 ~ 11)
• Prior to performing the following procedure, remove the metal
cover and CD changer mechanism assembly.
(1) Disconnect the card wires from connector CN870
and CN315 on the main board respectively.
(2) Remove the wire clamp and disconnect the wire from con-
nector CN703
(3) Disconnect the wire from connector CN220
former board.
(4) Remove the four screws F 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.
on the amplifier board.
, CN871
on the trans-
(Bottom)
(Bottom)
F
mplifier board
CN703
Transformer board
Wire clamp
CN220
Fig.8
Main board
CN870
CN871
CN315
Front panel
assembly
Fig.9
Front panel assembly
Fig.10
Joint a
Fig.11
Joint a
Front panel assembly
3.1.5 Removing the tuner board
(See Fig.12)
• Prior to performing the following procedure, remove the metal
cover.
(1) Disconnect the card wire from connector CN1
board on the right side of the body.
(2) Remove the plastic rivet fixing the tuner board.
(3) Remove the two screws G on the back of the body.
on the tuner
Plastic rivet
CN1
Tuner board
Rear panel
G
Fig.12
(No.MB012)1-9
3.1.6 Removing the rear cover / rear panel
(See Fig.13 ~ 16)
• Prior to performing the following procedure, remove the metal
cover and the CD changer mechanism assembly.
(1) Remove the screw H attaching the rear cover on the back
of the body.
(2) Push each tab of the four joints b in the direction of the ar-
row and release.
(3) Remove the sixteen screws G attaching the rear panel.
(4) Disengage the joints c on each lower side of the rear panel
using a screwdriver and remove the rear panel backward.
Joint b
G
G
Rear cover
H
Fig.13
Rear panel
Joint b
Rear panel
G
G
Fig.14
Rear panel
Fig.15
G
G
Joint c
1-10 (No.MB012)
Joint c
Rear panel
Fig.16
3.1.7 Removing the main board
A
(See Fig.17 ~ 19)
• Prior to performing the following procedure, remove the metal
cover, the CD changer mechanism assembly, the rear panel
and the antenna board.
(1) Disconnect the card wires from connector CN870
and CN315 on the main board.
(2) Disconnect the wires from connector CN704 and CN706
on the amplifier board.
(3) Disconnect the wire from connector CN710
board.
(4) Remove the screw I attaching the main board on the right
side ofthe body.
(5) Disconnect connector CN211
board from the regulator board.
3.1.8 Removing the speaker board
(See Fig.19)
• Prior to performing the following procedure, remove the metal
cover, the CD changer mechanism assembly and the rear panel.
REFERENCE:
It is not necessary to remove the main board.
(1) Disconnect connector CN217
the regulator board.
(2) Disconnect the wire from connector CN710
board.
and CN212 on the main
on the speaker board from
, CN871
on the speaker
on the speaker
CN315
CN871
mplifier board
CN704
CN706
Speaker board
CN710
Front panel assembly
Main board
CN870
Fig.17
Front panel assembly
Main board
Regulator board
Regulator board
Fig.18
Fig.19
I
CN212
Speaker board
CN217
CN211
CN710
(No.MB012)1-11
3.1.9 Removing the power board
(See Fig.20)
• Prior to performing the following procedure, remove the metal
cover, the CD changer mechanism assembly and the rear panel.
(1) Remove a wire clamp on the power board.
(2) Disconnect the wire from connector CN218
CN250 on the power board.
(3) Disconnect connector CN213
regulator board.
3.1.10 Removing the amplifier board / voltage board / heat sink
(See Fig.21, 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 CN703
CN706 on the amplifier board respectively.
(2) Remove the two wire clamps attaching the wire to the am-
plifier board and the voltage board.
(3) Disconnect connector CN215
CN216 on the voltage board from the regulator board (The
heat sink will be detached at once).
(4) Remove the four screws J attaching the amplifier board to
the heat sink.
(5) Remove the two screws K, the board bracket and the volt-
age board.
REFERENCE:
It is not necessary to remove the power board.
on the power board from the
on the amplifier board and
, CN219 and
, CN704 and
Power board
CN219
CN250
CN213
Amplifier board
Wire clamp
Voltage board
CN218
Wire clamp
Fig.20
Wire clamp
CN704
CN706
CN703
Regulator board
Heat sink
Voltage board
K
CN216
CN215
Fig.21
Amplifier board
J
J
Fig.22
1-12 (No.MB012)
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