JVC KD-S783M User manual

1-1
KD-S783M
SERVICE MANUAL
CD RECEIVER
No.49764
Nov. 2002
COPYRIGHT 2002 VICTOR COMPANY OF JAPAN, LTD.
KD-S783M
KD-S783M
Area Suffix
UF China
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
1-12
1-14
1-14
1-15~33

1-2
KD-S783M
!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-S783M
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-S783M
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, 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-S783M
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 the body upside down.
Insert a screwdriver to the two joints band two joints
con both sides of the body and the joint don the
back of the body, then detach the bottom cover from
the body.
1.
2.
Removing the bottom cover
(See Fig.5, 6)
When disengaging the joint dusing a
screwdriver, do not damage or break the
board.
CAUTION:
Fig.4
Fig.5
Fi
g
.6
Heat sink
AA
Joint b
Joint c
Joint d
Joint c
Joint b
Joint d
Bottom cover
Bottom cover
Rear panel
Rear panel

1-6
KD-S783M
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 four 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, 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 cassette
mechanism section on the back of the top chassis.
1.
Removing the CD mechanism section
(See Fig.9)
Fig.7
Fig.8
Fig.9
Main board
E
E
CN501
CD mechanism section
F
F
Top chassis
F
Rear panel
B
D
D
D
C
C
C

1-7
KD-S783M
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 eleven joints ewith 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 ~ 12)
Fig.10
Fig.11
Fi
g
.12
G
GG
G
Rear cover
Joint e
Front panel
Rear cover
Front panel
Control switch board
Joint e
Joint e
Joint e

1-8
KD-S783M
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
Fi
g
.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
A
e
h

1-9
KD-S783M
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
A
e
Fix plate (L)
g
g
Rear damper bracket
Fix arm (L)
Damper
E
Fix plate(R)
E
g
g
h

1-10
KD-S783M
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

1-11
KD-S783M
Adjustment method
Test instruments required for adjustment
1. Digital oscilloscope (100MHz)
2. AM Standard signal generator
3. FM Standard signal generator
4. Stereo modulator
5. Electric voltmeter
6. Digital tester
7. Tracking offset meter
8. Test Disc JVC :CTS-1000
9. Extension cable for check
EXTGS004-26P 1
Standard measuring conditions
Power supply voltage DC14.4V(10.5~16V)
Load impedance 4 (2 Speakers connection)
Line oout impeadance 20k
Output Level Line out 2.0V (Vol. MAX)
How to connect the extension cable for adjusting
Dummy load
Exclusive dummy load should be used for AM,and FM. For
FM dummy load,there is a loss of 6dB between SSG output
and antenna input.The loss of 6dB need not be considered
since direct reading of figures are applied in this working
standard.
Standard volume position
Balance and Bass &Treble volume : lndication"0"
Loudness : OFF
BBE : OFF
Frequency Band
FM 87.5MHz ~ 107.9MHz
MW 530kHz ~ 1710 kHz
EXTGS004-26P

1-12
KD-S783M
Power ON
Set Function to CD
Play
Jump to the first track
TOC readout
Tracking loop closed
Disc rotates
Disc inserted
YES
YES
Laser emitted
Pickup feed to the inner area
Focus search
RF signal eye-pattern
opens
RF signal eye-pattern
remains closed
"No disc"
display
• When correctly focused
Focus Servo Loop ON
• When the laser diode correctly
emits
Microprocessor
commands
Rough Servo Mode
CLV Servo Mode
(ProgramArea)
CLV Servo Mode
(Lead-In Area;
Digital: 0)
• RF signal
Flow of functional operation until TOC read
• When the pickup correctly moves
to the inner area of the disc
TERMINAL
Microprocessor
commands
FMO
TC9462 "53"
FEED MOTOR
+TERMINAL
IC581 "5"
REST SW
• When the disc correctly rotates
Tracking Servo Loop ON
Servo CLV
Rough
Servo
Acceleration
Acceleration
Acceleration
Microprocessor
commands
Spindle
motor (-)
IC581 "7"
0.5 Sec 0.5 Sec

1-13
KD-S783M
Feed Section
Focus Section
Tracking Section
Spindle Section
Is the voltage output at
IC521 pin "53" 5V or 0V?
Check the feed motor.
Is 4V present at both
sides of the feed motor?
Is the wiring for IC521
(90) ~ (100) correct?
Check IC581.
Is 6V or 2V present at
IC581 "5" and "6"?
Is 5V present at IC581
pin "11"?
Check the feed motor
connection wiring.
Check the vicinity of
IC521.
Check CD 9V
and 5V.
YES
YES
YES
NONO
NO
NO
NO
YES
YES
When the lens is
moving:
Check the circuits in
the vicinity of IC581
pins "15" ~ "18".
Check the pickup and
its connections.
NO
YES
YES
YES
Does the S-search
waveform appear at
IC581 pins "17" and "18"?
Is the disk rotated?
Does the RF signal
appear at TP1?
Is 4V present at IC581
pins "7" and "8" ?
Check the spindle motor
and its wiring.
Is 4V present at IC521
pin "55" ?
Check the vicinity of
IC581.
Check IC501 and
IC521.
YES
NO
NO
NO
NO NO
YES
YES
YES
Check the circuits in the
vicinity of IC501 "19" ~
"24" or the pickup
Is the RF waveform at TP1
distorted?
Proceed to the Tracking
section
When the disc is rotated
at first:
Check the circuit in the
vicinity of IC501 pins
"2" ~ "12".
Check IC521.
Check the pickup and
its connections.
YESYES
YES
Is the tracking error signal
output at IC501 "12"?
Approx. 1.2 V
4V

1-14
KD-S783M
Maintenance of laser pickup
(1) Cleaning the pick up lens
Before you replace the pick up, please try to
clean the lens with a alcohol soaked cotton
swab.
(2) Life of the laser diode
When the life of the laser diode has expired,
the following symptoms will appear.
(1) The level of RF output (EFM output:ampli
tude of eye pattern) will be low.
Replacement of laser pickup
Is RF output
1.0 0.35Vp-p? Replace it.
NO
YES
O.K
(3) Semi-fixed resistor on the APC PC board
The semi-fixed resistor on the APC printed
circuit board which is attached to the pickup
is used to adjust the laser power.Since this
adjustment should be performed to match the
characteristics of the whole optical block,
do not touch the semi-fixed resistor.
If the laser power is lower than the specified
value,the laser diode is almost worn out, and
the laser pickup should be replaced.
If the semi-fixed resistor is adjusted while
the pickup is functioning normally,the laser
pickup may be damaged due to excessive current.
Turn off the power switch and,disconnect the
power cord from the ac outlet.
Replace the pickup with a normal one.(Refer
to "Pickup Removal" on the previous page)
Plug the power cord in,and turn the power on.
At this time,check that the laser emits for
about 3seconds and the objective lens moves
up and down.
Note: Do not observe the laser beam directly.
Play a disc.
Check the eye-pattern at TP1.
Finish.

1-15
KD-S783M
Description of major ICs
1
24
2
15
16
13
3
4
5
6
78910 11 12 14 17 21 23
18
19
22
20
Buff.
ON/OFF
OSC circuit
AMP
AMP
AMP
Reference Counter
Phase
Comparator
Prescaler 4-bit
Swallow counter
12-bit
Programmable counter
Constant
power supply voltage
AM CP.
switch
switch
REG.
vt
FM cp
+
-
+
-
a-gnd
vccd-gndvdd
vdd2
out-2out-1
I/O -2I/O -1
SL
osc
XO
XI
FM VCO
AMVCO
IFC
CE
DIN
DOUT
DIMM
20-bit BINARY COUNTER
Serial
Interface
Resistor 1
Resistor 2 22-bit
40bit shift register
I/O PORT OUTPUT PORT Vdd Vcc
TB2118F-X (IC31) : PLL
1. Terminal layout
2. Block diagram
Pin
No.
Symbol I/O Function
1
2
3
4
5
6
7
8
9
10
11
12
XOUT
OSC
CE
DI
CK
DOUT
SR
I/01
I/02
OUT1
OUT2
VDD2
Crystal oscillator pin
Non connect
Chip enable input
Serial data input
Clock input
Serial data output
Register control pin
I/O ports
I/O ports
Non connect
Non connect
Single power supply for REF. frequency block
O
-
I
I
I
O
O
I/O
I/O
-
-
-
Pin
No.
Symbol I/O Function
13
14
15
16
17
18
19
20
21
22
23
24
IFC
VDD
FMIN
AMIN
DGND
FMCP
VT
AMCP
VCC
RF
AGND
XIN
IF signal input
Power pins for digital block
FM band local signal input
AM band local signal input
Connect to GND (for digital circuit)
Charge pump output for FM
Tuning voltage biased to 2.5V.
Charge pump output for AM
Power pins for analog block
Ripple filter connecting pin
Connect to GND (for analog circuit)
Crystal oscillator pin
I
-
I
I
-
O
-
O
-
I
-
I
3. Pin function
1 2 3 4 5 6 7 8 9
10 11 12
24 23 22 21 20 19 18 17 16 15 14 13

1-16
KD-S783M
20k 20k
20k
20k
20k
180k
60k
15pF
1
k
x0.5
x0.5
1.75k
240k
15pF
14k 2k
1k
2k 50k
x2
x2
240k
60k
80k
80k
20k
20k
180k
40pF
40pF
3k
3k
12k
12k
15k
50 A
10pF
20 A
40k
20k
20k 20k
50k
PEAK
15k
10pF
40k
60 A
1.3V
BOTTOM
PEAK
40k
30k
13GVSW
VRO
FEO
FEN
RFRP
RFRPIN
RFGO
RFGC
AGCIN
RFO
RFN
GND
14
15
16
17
18
19
20
21
22
23
24
12 RFDC
TEO
TEN
TEBC
SEL
LDO
MDI
TNI
TPI
FPI
FNI
Vcc
11
10
9
8
7
6
5
4
3
2
1
TA2147F-X (IC521) : RF amp.
1.Terminal layout
2.Block diagram

1-17
KD-S783M
3.Pin function
I/O
-
I
I
I
I
I
O
I
I
I
O
O
I
O
O
I
O
I
O
I
I
O
I
-
Function
3.3V Power supply pin
Main-beam amp input pin
Main-beam amp input pin
Sub-beam amp input pin
Sub-beam input pin
Monitor photo diode amp input pin
Laser diode amp output pin
APC circuit ON/OFF control signal,laser diode (LDO) control signal input or
bottom/peak detection frequency change pin.
Tracking error balance adjustment signal pin
Adjusts TE signal balance by eliminating carrier component from
PWM signal(3-state output, PWM carrier = 88.2kHz) output from
TC9490F/FA TEBC pin using RC-LPF and inputting DC.
TEBC input voltage:GND~Vcc
Tracking error signal generation amp negative-phase input pin
Tracking error signal generation amp output pin.
Combining TEO signal and RFRP signal with TC9490F/FA configures
tracking search system.
RF signal peak detection output pin
AGC/FE/TE amp gain change pin
Reference voltage (VRO) output pin *VRO = 1/2 Vcc when Vcc = 3.3V
Focus error signal generation amp output pin
Focus error signal generation amp negative-phase input pin
Signal amp output pin for track count
Combining RFRP signal TEO signal with TC9490F/FA configures tracking
search system.
Signal generation amp input pin for track count
RF signal amplitude adjustment amp output pin
RF amplitude adjustment control signal input pin
Adjusts RF signal amplitude by eliminating carrier component from PWM
signal (3-state output, PWM carrier = 88.2kHz) output from TC9490F/FA
RFGC pin using RC-LPF and inputting DC.
*RFGC input voltage : GND-Vcc
RF signal amplitude adjustment amp input pin
RF signal generation amp output pin
RF signal generation amp input pin
GND pin
Symbol
Vcc
FNI
FPI
TPI
TNI
MDI
LDO
SEL
TEBC
TEN
TEO
RFDC
GVSW
VRO
FEO
FEN
RFRP
RFRPIN
RFGO
RFGC
AGCIN
RFO
RFN
GND
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
LDOSEL
GND OFF
HIZ
Vcc
ON
ON
Connected to Vcc
through 1k resistor
Control signal output
Control signal output
APC
circuit
ModeGVSW
GND
HIZ
Vcc
CD-RW
CD-DA
CD-DA

1-18
KD-S783M
11
6 20
1
4
10
15
25
13
14
16
12
9
8
5
7
2
22
17
19
18
21
23
24
3
-
+
-
+
-
+
-
+
-
+
-
+
-
+
-
+
IN 1
IN 2
ST BY
Vcc 1/2 Vcc 3/4
OUT 1+
OUT 1-
PWR GND1
OUT 2+
OUT 2-
PWR GND2
R.F
IN 3
IN 4
PRE GND
ON TIME C Muting &
ON Time Control
Circuit
Protective
circuit
Protective
circuit
Mute
circuit
Ripple
Filter
Stand by
Switch
N.C
+
+
0.22 F
2200 F 0.022
F
0.22 F
TA B
+5V
ST ON
+
+
+
+
47 F
0.22 F
0.22 F
22 F
+
Mute 10K
+
3.3 F
OUT 3+
OUT 3-
Low Level
Mute ON
PWR GND3
OUT 4+
OUT 4-
PWR GND4
LA4743K (IC301) : Power amp
1.Block diagram

1-19
KD-S783M
2.Terminal layout
3.Pin function LA4743B
TA B
GND
OUTRR-
STBY
OUTRR+
VCC1/2
OUTRF-
GND
OUTRF+
RIPPLE
INRF
INRR
SGND
INLR
INLF
ONTIME
OUTLF+
GND
OUTLF-
VCC3/4
OUTLR+
MUTE
OUTLR-
GND
NC
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
SymbolPin No. Function
Header of IC
Power GND
Outpur(-) for front Rch
Stand by input
Output (+) for front Rch
Power input
Output (-) for rear Rch
Power GND
Output (+) for rear Rch
Ripple filter
Rear Rch input
Front Rch input
Signal GND
Front Lch input
Rear Lch input
Power on time control
Output (+) for rear Lch
Power GND
Output (-) for rear Lch
Power input
Output (+) for front
Muting control input
Output (-) for front
Power GND
Non connection

1-20
KD-S783M
UPD784215AGC184 (IC701) : Main micon
1.Pin layout
2.Pin functions (1/2)
1
~
25
75
~
51
100 ~ 76
26 ~ 50
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19~21
22
23
24
25
26
27
28
29
30
31
32
33
34,35
36
37
38
39
40
41
42
43
44
45~52
I/O
I
I
I
I
O
O
-
O
-
-
-
-
-
-
I
I
I
I
-
I
-
-
I
I
I
I
I
I
-
I
-
-
-
I
O
I/O
O
O
O
O
O
-
Function
CD mecha sw2
CD mecha sw3
CD mecha sw4
Rest sw
Loading/Eject motor control (Loading side)
Loading/Eject motor control (Eject side)
No use
Antenna remote control
Maicon power supply
GND
Reset detection
CD mecha sw1
J-BUS int
Power save 2, H means STOP mode
No use
Remocon input
A/D converter power supply
A/D reference voltage
Volume encoder pulse input 1
Volume encoder pulse input 2
Key input 0
Key input 1
Key input 2
Level meter input
No use
S.METER input
GND
No use
J-BUS data input
J-BUS data output
J-BUS clock input/output
J-BUS I/O selection output H:output L:input
Data output for LCD driver
CLK output for LCD driver
CE for LCD driver
Buzzer output
No use
Symbol
SW2
SW3
SW4
REST
LM0
LM1
-
ANT CONT
VDD
X2
X1
VSS
XT2
XT1
RESET
SW1
BUS-INT
PS2
-
REMOCON
AVDD
AVREF0
VOL1
VOL2
KEY0
KEY1
KEY2
LEVEL
-
SM
AVSS
-
AVREF
BUS-SI
BUS-SO
BUS-SCK
BUS-I/O
LCD-DA
LCD-SCK
LCD-CE
BUZZER
-