JVC KD-S747, KD-SX747 Service Manual
49822200303
KD-S747
SERVICE MANUAL
CD RECEIVER
KD-S747
COMPACT
DIGITAL AUDIO
EE --------- Russian Fedeation
Area Suffix
TABLE OF CONTENTS
1 Important Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
2 Disassembly method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
3 Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-23
4 Description of major ICs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-27
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LTD.
No.49822
2003/03
KD-S747
1.1 Safety Precautions
SECTION 1
Important Safety 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.
1-2 (No.49822)
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 DVD 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
KD-S747
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) I t 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 CDpickup 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
Short-circuit point
Pickup
Pickup
(No.49822)1-3
KD-S747
Disassembly method
2.1 Main body
2.1.1 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 in
the direction of the arrow.
2.1.2 Removing the front chassis assembly
(See Figs.2 and 3)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Remove the screw A on the both sides of the main body.
(2) Release the two joints a and two joints b on both sides
of the main body using a screwdriver, and remove the front
chassis assembly forward.
SECTION 2
Front panel assembly
Fig.1
Detach button
a
Joint
A
Joint b
A
Joint b
Front chassis assembly
Joint a
Front chassis assembly
Fig.2
Fig.3
1-4 (No.49822)
2.1.3 Removing the heat sink
(See Fig.4)
(1) Remove the two screws B and two screws C on the left
side of the main body.
KD-S747
B
2.1.4 Removing the bottom cover
(See Figs.5 and 6)
• Prior to performing the following procedure, remove the front
panel assembly, front chassis assembly and heat sink.
(1) Turn over the body and release the two joints c, two joints
d and joint e .
CAUTION:
Do not damage the main board when releasing the joint e us-
ing a screwdriver. (See Figs.5 and 6)
Joint
Joint e
C
Heat sink
Fig.4
c
Bottom cover
Joint d
Fig.5
Joint d
Bottom cover
Joint c
Joint e
Fig.6
(No.49822)1-5
KD-S747
2.1.5 Removing the rear bracket
(See Fig.7)
• Prior to performing the following procedure, remove the front
panel assembly, front chassis assembly, heat sink and bottom
cover.
(1) Remove the three screws D, screw E and two screws F on
the back of the body.
(2) Remove the rear bracket.
Rear bracket
F
2.1.6 Removing the main board
(See Fig.8)
• Prior to performing the following procedure, remove the front
panel assembly, front chassis assembly, heat sink, bottom
cover and rear bracket.
(1) Remove the two screws G attaching the main board.
(2) Disconnect connector CN501 and remove the main board.
2.1.7 Removing the CD mechanism assembly
(See Fig.9)
• Prior to performing the following procedure, remove the front
panel assembly,front chassis assembly, heat sink, bottom cover, rear bracket and main board.
(1) Remove the three screws H .
DD
Fig.7
Main board
G
CN501
Fig.8
E
G
H
1-6 (No.49822)
CD mechanism assembly
Top chassis
H
Fig.9
2.1.8 Removing the front board
f
(See Figs.10 to 12)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Remove the four screws J on the back side of the front
panel assembly.
(2) Release the twelve joints f .
(3) Take out the front board.
KD-S747
J
J
Front panel
Joint f
Front board
J
Fig.10
Joint f
Joint
Joint f
Joint f
Rear cover
Fig.11
Fig.12
(No.49822)1-7
KD-S747
A
2.2 CD Mechanism Assembly
2.2.1 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
1-8 (No.49822)
KD-S747
2.2.2 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 instruction 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.49822)1-9
KD-S747
2.2.3 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.
DET switch
Connector
board
Pickup
Fig.6
DET switch
Tab c
Tab c
DET switch wire
Feed sw. holder
Fig.7
1-10 (No.49822)
2.2.4 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)
KD-S747
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.49822)1-11
KD-S747
2.2.5 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
Clamper assembly
Fig.10
Clamper arm spring
Chassis rivet
assembly
Joint d
Joint d
Chassis rivet assembly
Clamper
assembly
Joint d
Fig.11
1-12 (No.49822)
2.2.6 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.
KD-S747
Loading / feed motor assembly
Fig.12
Loading / feed motor assembly
C
Fig.13
(No.49822)1-13
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