JVC KDS-845 Service manual
SERVICE MANUAL
CD RECEIVER
4985820035
KD-S845
D
45Wx4
7
10
8
9
KD-S845
11
12
RPT
N
BA
TUNER
RND
SCM
Area Suffix
U ------- Other Areas
TABLE OF CONTENTS
1 Important Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 Disassembly method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
3 Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4 Description of major ICs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LTD.
No.49858
2003/5
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.49858)
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 conducti ve sheet) or an iron plate over it before placing the
traverse unit (optical pickup) on it.
(2) Grou nd 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 insta llation, both sides of the lase r diode on the replacement o ptical
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 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.49858)1-3
SECTION 2
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 left part of the front
panel and remove the front panel assembly in the direction
of the arrow.
2.1.2 Removing the front chassis assembly
(See Figs.2 to 3)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Release the two joints a and two joints b on both sides of
the main body.
(2) Release the two joints c on the bottom side of the main
body and remove the front chassis assembly in the direction of the arrow.
Front panel assembly
Joint
a
Fig.1
Eject button
Joint
b
Joint
a
Front chassis assembly
Joint c Joint c
Fig.2
Front chassis assembly
Fig.3
Joint
b
1-4 (No.49858)
2.1.3 Removing the heat sink
(See Fig.4)
(1) Remove the three screws A on the left side of the main
body.
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 main body and relea se the two joints d, two
joints e and joint f.
CAUTION:
Do not damage the main board when releasing the joint f using
a screwdriver. (See Figs.5 and 6)
A
Joint d
Joint f
Rear panel
Bottom cover
Heat sink
Fig.4
Fig.5
A
Bottom cover
Joint e
Joint e
Joint d
Joint f
Rear panel
Fig.6
(No.49858)1-5
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) Remo v e the one screws B, for screws C and three screws
D on the back side of the main body.
(2) Remove the rear bracket.
CC
Rear bracket
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 E attaching the main board.
(2) Disconnect the 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, main board and CD mecha board.
(1) Remove the three screws F.
F
B
E
Top chassis
DD
Fig.7
Main board assembly
E
CN501
Fig.8
CD mechanism section
F
1-6 (No.49858)
F
Fig.9
2.1.8 Removing the front board
(See Figs. 10 to 12)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Remove the fo ur screws G on the back side of the front
panel assembly.
(2) Release the ten joints g.
(3) Take out the front board.
G
GG
Fig.10
Front panel
Joint g
Rear cover
Front board
Joint g
Joint g
Fig.11
Fig.12
Joint g
Joint g
(No.49858)1-7
2.2 CD mechanism section
2.2.1 Removing the CD mechanism control board
(See Fig.1 and 2)
(1) Unsolde r the part a and b on the CD mechanism control
board.
(2) Remove the stator fixing the CD mechanism control board
and the damper bracket (To remove the stator smoothly,
pick up the center part).
(3) Remove the screw A attaching the CD mechanism control
board.
(4) Re move the CD mechanism control board in the direction
of the arrow while releasing it from the two damper bracket
slots d and the front bracket slot e.
(5) Disco nnect the flexible wire from connector on the pickup
unit.
ATTENTION:
Turn the FD gear in the direction of the arrow to move the entire pickup unit to the appropriate position where the flexible
wire of the CD mechanism unit can be disconnected easily.(Refer to Fig.2)
CD mechanism assembly
D
h
Front bracket
Pickup unit
Damper bracket
D
A
Fig.1
e
b
Flexible wire
a
h
c
D
d
CD mechanism
control board
FD gear
Shift the lock
Fig.2
1-8 (No.49858)
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