JVC KD-S821R User manual

SERVICE MANUAL
CD RECEIVER
No.49679
Feb. 2002
COPYRIGHT 2002 VICTOR COMPANY OF JAPAN, LTD.
KD-S821R
KD-S821R
Area Suffix
Contents
Safety precaution
Preventing static electricity
Disassembly method
Adjustment method
1-2
1-3
1-4
1-11
Flow of functional
operation unit TOC read
Maintenance of laser pickup
Replacement of laser pickup
Description of major ICs
2-1
2-3
2-3
2-6
E -------- Continental Europe
EX ------ Central Europe
45Wx4 KD-S821R
789
10 11 12 RDS
MO
RND
DISP
TP PTY SCM
COMPACT
DIGITAL AUDIO

1-2
KD-S821R
!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.
Safety precaution
!Please use enough caution not to see the beam directly or touch it in case of an
adjustment or operation check.

1-3
KD-S821R
Front bracket
CD mechanism
control board
Damper bracket
CD mechanism ass’y
FD screw
Feed motor ass’y
FD gear Pickup unit
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
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.
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.
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 tester's internal power
source can easily destroy the laser diode.
4.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
Conductive material
(conductive sheet) or iron plate
(caption)
Anti-static wrist strap
Soldering
Attention when traverse unit is decomposed
1.Solder is put up before the card wire is removed from connector on
the CD substrate as shown in Figure.
(When the wire is removed without putting up solder, the CD pick-up
assembly might destroy.)
2.Please remove solder after connecting the card wire with
when you install picking up in the substrate.
*Please refer to "Disassembly method" in the text for pick-up and how to
detach the substrate.

1-4
KD-S821R
Press the eject button in the lower right part of the
front panel. Remove the front panel assembly from
the body.
1.
Removing the front panel assembly
(See Fig.1)
Prior to performing the following procedure, remove
the front panel assembly.
Release the four joint tabs aon both sides of the
front chassis assembly and remove the front chassis
assembly toward the front.
1.
Removing the front chassis assembly
(See Fig.2 and 3)
Disassembly method
<Main body>
Fig.1
Fig.2
Fig.3
Front panel assembly
Eject button
Tab a
Tab a
Front chassis assembly
Front chassis
assembly
Heat sink Tab a
Tab a

1-5
KD-S821R
Remove the three screws Aon the left side of the
body.
1.
Removing the heat sink (See Fig.4)
Prior to performing the following procedure, remove
the front panel assembly, the front chassis assembly
and the heat sink.
Turn over the body and unjoint the five joints bwith
the bottom cover and the body using a screwdriver.
1.
Removing the bottom cover
(See Fig.5 and 6)
Fig.4
Fig.5
Fig.6
Heat sink
A
Joints b
Joints b
Joint b
Joints b
Joints b
Joint b
Bottom cover
Bottom cover
Rear panel
Rear panel
A

1-6
KD-S821R
Prior to performing the following procedure, remove
the front panel assembly, the front chassis assembly,
the heat sink and the bottom cover.
Remove the screw B, the two screws C and the
three screws Dattaching the rear bracket on the
back of the body. Remove the rear panel.
Remove the two screws Eattaching the main board
on the bottom of the body. Disconnect connector
CN501 on the main board in the direction of the
arrow.
1.
2.
Removing the main board
(See Fig.7 and 8)
Prior to performing the following procedure, remove
the front panel assembly, the front chassis assembly,
the heat sink, the bottom cover and the main board.
Remove the three screws Fattaching the CD
mechanism section on the back of the top chassis.
1.
Removing the CD mechanism section
(See Fig.9)
Fig.7
Fig.8
Fig.9
Rear panel
B
D
D
D
C
Main board
E
E
CN501
CD mechanism section
F
F
F
Top chassis
C

1-7
KD-S821R
Prior to performing the following procedure, remove
the front panel assembly.
Remove the four screws Gattaching the rear cover
on the back of the front panel assembly.
Unjoint the twelve joints cwith the front panel and
the rear cover.
Remove the control switch board on the back of the
front panel.
1.
2.
3.
Removing the control switch board
(See Fig.10 to 12)
Fig.10
Fig.11
Fig.12
G
GG
G
Rear cover
Front panel
Control switch board
Joints c
Joints c
Front panel
Rear cover
Joints c
Joints c

1-8
KD-S821R
Unsolder the part aand bon the CD mechanism
control board.
Remove the stator fixing the CD mechanism control
board and the damper bracket (To remove the stator
smoothly, pick up the center part).
Remove the screw Aattaching the CD mechanism
control board.
Remove the CD mechanism control board in the
direction of the arrow while releasing it from the two
damper bracket slots dand the front bracket slot e.
Disconnect the flexible wire from connector on the
pickup unit.
1.
2.
3.
4.
5.
Removing the CD mechanism control
board (See Fig.1 and 2)
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)
ATTENTION:
Prior to performing the following procedure, remove
the CD mechanism control board.
Remove the two springs fattaching the CD
mechanism assembly and the front bracket.
Remove the two screws Band the front bracket
while pulling the flame outward.
Remove the belt and the screw Cfrom the loading
motor.
1.
2.
3.
Removing the loading motor
(See Fig.3 to 5)
<CD mechanism section>
Fig.2
Fig.3
Fig.4
Shift the lock
Flexible wire
Pickup unit
FD gear
CD mechanism control board
Loading motor Front bracket
Front bracket Pull outward
Pull outward
Flame
f
B
f
B
Fig.5
C
Loading motor
Belt
Fig.1
Front bracket CD mechanism
control board
Damper bracket
h
c
d
b
a
DD
D
CD mechanism assembly
Ae
h

1-9
KD-S821R
Prior to performing the following procedure, remove
the CD mechanism control board and the front
bracket (loading motor).
Remove the three screws Dand the damper
bracket.
Raise the both sides fix arms and move the fix plates
in the direction of the arrow to place the four shafts g
as shown in Fig.8 and 9.
Remove the CD mechanism assembly and the two
springs hattaching the flame.
Remove the two screws Eand both sides rear
damper brackets from the dampers. Detach the CD
mechanism assembly from the left side to the right
side.
1.
2.
3.
4.
Removing the CD mechanism assembly
(See Fig.1, 6 to 9)
The CD mechanism assembly can be
removed if only the rear damper
bracket on the left side is removed.
ATTENTION:
Fig.6
Fig.7
Fig.8
Fig.9
Rear damper bracket
Fix arm (R)
Damper
DD
Damper bracket
CD mechanism
assembly
Flame h
h
D
D
Fig.5
Front bracket CD mechanism
control board
Damper bracket
h
c
d
b
a
DD
D
CD mechanism assembly
Ae
Fix plate (L)
g
g
Rear damper bracket Fix arm (L)
Damper
E
Fix plate(R)
E
g
g
h

1-10
KD-S821R
Prior to performing the following procedure, remove
the CD mechanism control board, the front bracket
(loading motor) and the CD mechanism assembly.
Remove the two screws Fand the feed motor
assembly.
1.
Removing the feed motor assembly
(See Fig.10)
Prior to performing the following procedure, remove
the CD mechanism control board, the front bracket
(loading motor), the CD mechanism assembly and
the feed motor assembly.
Detach the FD gear part of the pickup unit upward.
Then remove the pickup unit while pulling out the
part iof the FD screw.
1.
Remove the screw Gattaching the nut push spring
plate and the pickup mount nut from the pickup unit.
Pull out the FD screw.
2.
Removing the pickup unit
(See Fig.10 and 11)
When reattaching the pickup unit,
reattach the part jof the pickup unit,
then the part iof the FD screw.
ATTENTION:
Prior to performing the following procedure, remove
the CD mechanism control board, the front bracket
(loading motor), the CD mechanism assembly and
the feed motor assembly.
Turn up the CD mechanism assembly and remove
the two springs kon both sides of the clamper arms.
Open the clamper arm upward.
Turn the turn table, and remove the two screws H
and the spindle motor.
1.
2.
Removing the spindle motor
(See Fig.12 and 13)
Fig.10
Fig.11
Fig.12
Fig.13
Spindle motor
kk
Pickup unit
Part i
FD screw
Feed motor assembly
FD gear Pickup unit
Part j
F
Nut push spring plate
Pickup mount nut
Pickup unit
FD screw
G
H
H