JVC KD G118 Service Manual
SERVICE MANUAL
CD RECEIVER
MA18620056
KD-G118
Area suffix
UF -------------------------- China
Lead free solder used in the board (material : Sn-Ag-Cu, melting point : 219 Centigrade)
TABLE OF CONTENTS
1 PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-25
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-26
COPYRIGHT © 2005 Victor Company of Japan, Limited
No.MA186
2005/6
SPECIFICATION
AUDIO AMPLIFIER SECTION
Maximum Power Output Front 50 W per channel
Rear 50 W per channel
Continuous Power Output (RMS) Front 19 W per channel into 4 Ω, 40 Hz to 20 000 Hz at no more
than 0.8% total harmonic distortion.
Rear 19 W per channel into 4 Ω, 40 Hz to 20 000 Hz at no more
than 0.8% total harmonic distortion.
Load Impedance 4 Ω (4 Ω to 8 Ω allowance)
Tone Control Range Bass ±10 dB at 100 Hz
Treble ±10 dB at 10 kHz
Frequency Response 40 Hz to 20 000 Hz
Signal-to-Noise Ratio 70 dB
Line-Out Level/Impedance 2.0 V/20 kΩ load (full scale)
Output Impedance 1 kΩ
TUNER SECTION
Frequency Range FM 87.5 MHz to 108.0 MHz
AM 531 kHz to 1 602 kHz
FM Tuner Usable Sensitivity 11.3 dBf (1.0 µV/75 Ω)
50 dB Quieting Sensitivity 16.3 dBf (1.8 µV/75 Ω)
Alternate Channel Selectivity (400 kHz) 65 dB
Frequency Response 40 Hz to 15 000 Hz
Stereo Separation 35 dB
Capture Ratio 1.5 dB
AM Tuner Sensitivity 20 µV
Selectivity 35 dB
CD PLAYER SECTION
Type Compact disc player
Signal Detection System Non-contact optical pickup (semiconductor laser)
Number of channels 2 channels (stereo)
Frequency Response 5 Hz to 20 000 Hz
Dynamic Range 96 dB
Signal-to-Noise Ratio 98 dB
Wow and Flutter Less than measurable limit
GENERAL
Power Requirement Operating Voltage DC 14.4 V (11 V to 16 V allowance)
Grounding System Negative ground
Allowable Operating Temperature 0°C to +40°C
Dimensions (W × H × D) Installation Size (approx.) 182 mm × 52 mm × 150 mm
Panel Size (approx.) 188 mm × 58 mm × 11 mm
Mass (approx.) 1.3 kg (excluding accessories)
Design and specifications are subject to change without notice.
1-2 (No.MA186)
1.1 Safety Precautions
SECTION 1
PRECAUTIONS
!
!
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.
Please use enough caution not to see the beam directly or touch it in case of an
adjustment or operation check.
(No.MA186)1-3
1.2 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.
1.2.1 Grounding to prevent damage by static electricity
Static electricity in the work area can destroy the optical pickup (laser diode) 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 sheet) 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 plate
(3) Handling the optical pickup
• 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.)
• 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.
1.3 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 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 before the flexible wire is disconnected from the connector on the CD pickup unit.
(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 after connecting the flexible wire.
Short-circuit point
(Soldering)
Flexible wire
1-4 (No.MA186)
Pickup
1.5 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 CD,MD and DVD 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.
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 here in 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 LABELS
WARNING LABEL
CAUTION : Visible and Invisible
CLASS 1
LASER PRODUCT
laser radiation when open and
interlock failed or defeated.
AVOID DIRECT EXPOSURE TO
BEAM. (e)
ADVARSEL : Synlig og usynlig
laserstråling når maskinen er
åben eller interlocken fejeler.
Undgå direkte eksponering til
stråling. (d)
VARNING : Synlig och
osynling laserstrålning när
den öppnas och spärren är
urkopplad. Betrakta ej
strålen. (s)
VARO : Avattaessa ja suojalukitus
ohitettuna tai viallisena olet alttiina
näkyvälle ja näkymättömälle
lasersäteilylle. Vältä säteen
kohdistumista suoraan itseesi. (f)
(No.MA186)1-5
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.
1-6 (No.MA186)
SECTION 3
DISASSEMBLY
3.1 Main body section
3.1.1 Removing the front panel assembly
(See Fig.1)
(1) Push the detach button in the lower right part of the front
panel assembly and remove the front panel assembly.
3.1.2 Removing the bottom cover
(See Fig.2)
(1) Turn the main body up side down.
(2) Insert a screwdriver under the joints to release the two
joints a on the left side, two joints b on the right side and
joint c on the back side of the main body, then remove the
bottom cover from the main body.
Note:
When releasing the joints using a screwdriver, do not damage
the main board.
Front panel assembly
Joint a
Detach button
Fig.1
Bottom cover
Joint b
3.1.3 Removing the front chassis assembly
(See Fig.3)
• Remove the front panel assembly and bottom cover.
(1) Remove the two screws A on the both sides of the main
body.
(2) Release the two joints d and two joints e on the both sides
of the main body, then remove the front chassis assembly
toward the front.
Joint a
Joint c
Fig.2
Joint d Joint e
A
Joint d
Front chassis assembly
Fig.3
Joint e
Joint b
(No.MA186)1-7
3.1.4 Removing the side panel
(See Fig.4)
Reference:
Remove the front panel assembly as required.
(1) Remove the screw B and two screws C attaching the side
panel on the left side of the main body.
(2) Remove the side panel from the main body.
3.1.5 Removing the rear bracket
(See Fig.5)
• Remove the bottom cover.
(1) Remove the three screws D, three screws E and two
screws F attaching the rear bracket on the back side of the
main body.
(2) Remove the rear bracket.
3.1.6 Removing the main board
(See Figs.5 and 6)
• Remove the front panel assembly, bottom cover and side pan-
el.
Reference:
Remove the front chassis assembly as required.
(1) Remove the three screws D attaching the rear bracket on
the back side of the main body. (See Fig.5.)
(2) Remove the two screws G attaching the main board. (See
Fig.6.)
(3) Disconnect the connector CN501
the main body and take out the main board with the rear
bracket. (See Fig.6.)
Reference:
Remove the rear bracket from the main body as required. (See
"3.1.5 Removing the rear bracket".)
on the main board from
C
B
Side panel
Fig.4
Rear bracket
EF
F
C
E
DD
Fig.5
CN501
G
Main board
G
1-8 (No.MA186)
Rear bracket
Fig.6
3.1.7 Removing the CD mechanism assembly
(See Fig. 7)
• Remove the front panel assembly, bottom cover, side panel,
rear bracket and main board.
Reference:
Remove the front chassis assembly as required.
(1) Remove the three screws H attaching the CD mechanism
assembly on the top chassis.
(2) Take out the CD mechanism assembly.
H
3.1.8 Removing the front board
(See Figs.8 to 10)
• Remove the front panel assembly.
(1) Remove the five screws J on the back side of the front pan-
el assembly. (See Fig.8.)
(2) Release the twelve joints f and remove the rear cover. (See
Fig.9.)
(3) Release the joint g and take out the front board from the
front panel assembly. (See Fig.10.)
Note:
When removing the rear cover assembly and front board, be
careful not to lose the spring.
CD mechanism assembly
J
Rear cover
Top chassis
H
Fig.7
J
J
Fig.8
Joints f
Joints f Joints f
Front board
Joints f
Fig.9
Front panel assembly
Joint g
Fig.10
(No.MA186)1-9
3.2 CD Mechanism Assembly
A
3.2.1 Removing the top cover
(See Figs.1 and 2)
(1) Remove the two screws A on the both side of the body.
(2) Lift the front side of the top cover and move the top cover
backward to release the two joints a.
Top cover
Joints a
A
Joints a
A
Fig.1
Fig.2
Top cover
1-10 (No.MA186)
3.2.2 Removing the connector board
(See Figs.3 to 5)
CAUTION:
Before disconnecting the flexible wire from the pickup, solder
the short-circuit point on the pickup. No observance of this in-
struction may cause damage of the pickup.
(1) Remove the screw B fixing the connector board.
(2) Solder the short-circuit point on the connector board.
(3) Disconnect the flexible wire from the pickup.
(4) Move the connector board in the direction of the arrow to
release the two joints b.
(5) Unsolder the wire on the connector board if necessary.
CAUTION:
Unsolder the short-circuit point after reassembling.
B
Connector board
Flexible wire
Wires
Joints b
Short-circuit point
Fig.3
Short-circuit point
(Soldering)
Pickup
Flexible wire
Frame
Pickup
Fig.4
B
Connector board
Fig.5
(No.MA186)1-11
3.2.3 Removing the DET switch
(See Figs.6 and 7)
(1) Extend the two tabs c of the feed sw. holder and pull out
the switch.
(2) Unsolder the DET switch wire if necessary.
Connector
board
DET switch
DET switch
Pickup
Fig.6
Tab c
DET switch wire
Tab c
Feed sw. holder
Fig.7
1-12 (No.MA186)
3.2.4 Removing the chassis unit
r
(See Figs.8 and 9)
• Prior to performing the following procedure, remove the top
cover and connector board.
(1) Remove the two suspension springs (L) and (R) attaching
the chassis unit to the frame.
CAUTION:
• The shape of the suspension spring (L) and (R) are different. Handle them with care.
• When reassembling, make sure that the three shafts
on the underside of the chassis unit are inserted to the
dampers certainly.
Suspension spring (R)
Chassis unit
Suspension spring (L)
Frame
Suspension spring (R)
Chassis unit
Shafts
Damper
Damper
Suspension spring (L)
Fig.8
Shaft
Dampe
Frame
Fig.9
(No.MA186)1-13
3.2.5 Removing the clamper assembly
(See Figs.10 and 11)
• Prior to performing the following procedure, remove the top
cover.
(1) Remove the clamper arm spring.
(2) Move the clamper assembly in the direction of the arrow to
release the two joints d.
Clamper arm
spring
Joint d
Joint d
Clamper assembly
Fig.10
Clamper arm spring
Chassis rivet
assembly
Joint d
Clamper
assembly
Chassis rivet assembly
Fig.11
Joint d
1-14 (No.MA186)
3.2.6 Removing the loading / feed motor assembly
(See Figs.12 and 13)
• Prior to performing the following procedure, remove the top
cover, connector board and chassis unit.
(1) Remove the screw C and move the loading / feed motor
assembly in the direction of the arrow to remove it from the
chassis rivet assembly.
(2) Disconnect the wire from the loading / feed motor assembly
if necessary.
CAUTION:
When reassembling, connect the wire from the loading /
feed motor assembly to the flame as shown in Fig.12.
Loading / feed motor assembly
Fig.12
Loading / feed motor assembly
C
Fig.13
(No.MA186)1-15
3.2.7 Removing the pickup unit
(See Figs.14 to 18)
• Prior to performing the following procedure, remove the top
cover, connector board and chassis unit.
(1) Remove the screw D and pull out the pu. shaft holder from
the pu. shaft.
(2) Remove the screw E attaching the feed sw. holder.
(3) Move the part e of the pickup unit upward with the pu. shaft
and the feed sw. holder, then release the joint f of the feed
sw. holder in the direction of the arrow. The joint g of the
pickup unit and the feed rack is released, and the feed sw.
holder comes off.
(4) Remove the pu. shaft from the pickup unit.
(5) Remove the screw F attaching the feed rack to the pickup
unit.
3.2.8 Reattaching the pickup unit
(See Figs.14 to 17)
(1) Reattach the feed rack to the pickup unit using the screw F.
(2) Reattach the feed sw. holder to the feed rack while setting
the joint g to the slot of the feed rack and setting the part f
of the feed rack to the switch of the feed sw. holder correctly.
(3) As the feed sw. holder is temporarily attached to the pickup
unit, set to the gear of the joint g and to the bending part of
the chassis (joint h) at a time.
CAUTION:
Make sure that the part i on the underside of the feed
rack is certainly inserted to the slot j of the change lock
lever.
(4) Reattach the feed sw. holder using the screw E.
(5) Reattach the pu. shaft to the pickup unit. Reattach the pu.
shaft holder to the pu. shaft using the screw D.
Feed sw. holder
Joint f
Joint g
Feed sw.
holder
Part e
Feed rack
Part i
E
Pickup unit
Slot j
F
Fig.15
Pu. shaft
Pickup unit
Joint f
Joint h
Fig.16
Feed rack
Pickup unit
Feed sw. holder
D
Pu. shaft
holder
Pu. shaft
D
Pu. shaft holder
1-16 (No.MA186)
Pickup unit
Fig.14
Part e
E
Joint g
Feed rack
Fig.17
Pickup unit
Joint g
Joint f
Feed sw. holder
Fig.18
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