Jvc KD-S783-M Service Manual
SERVICE MANUAL
CD RECEIVER
KD-S783M
KD-S783M
KD-S783M
Contents
Safety precaution
Preventing static electricity
Disassembly method
Adjustment method
COPYRIGHT 2002 VICTOR COMPANY OF JAPAN, LTD.
1-2
1-3
1-4
1-11
Area Suffix
UF China
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
No.49764
Nov. 2002
1-1
KD-S783M
Safety precaution
!
!
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
KD-S783M
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.
(caption)
Anti-static wrist strap
Conductive material
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.
(conductive sheet) or iron plate
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
CD mechanism ass’y
Damper bracket
Attention when traverse unit is decomposed
*Please refer to "Disassembly method" in the text for pick-up and how to
detach the substrate.
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.
Front bracket
Feed motor ass’y
FD screw
CD mechanism
control board
Soldering
FD gear
Pickup unit
1-3
KD-S783M
Disassembly method
<Main body>
Removing the front panel assembly
(See Fig.1)
1.
Press the eject button in the lower right part of the
front panel. Remove the front panel assembly from
the body.
Front panel assembly
Eject button
Fig.1
Removing the front chassis assembly
(See Fig.2, 3)
Prior to performing the following procedure, remove
the front panel assembly.
1.
Release the four joint tabs a on both sides of the
front chassis assembly and remove the front chassis
assembly toward the front.
Tab a
Tab a
Front chassis assembly
Heat sink
Fig.2
Tab a
1-4
Fig.3
Tab a
Front chassis
assembly
Removing the heat sink (See Fig.4)
g
1.
Remove the three screws A on the left side of the
body.
KD-S783M
Removing the bottom cover
(See Fig.5, 6)
Prior to performing the following procedure, remove
the front panel assembly, the front chassis assembly
and the heat sink.
1.
Turn the body upside down.
2.
Insert a screwdriver to the two joints b and two joints
c on both sides of the body and the joint d on the
back of the body, then detach the bottom cover from
the body.
CAUTION:
When disengaging the joint d using a
screwdriver, do not damage or break the
board.
A
Joint d
Joint b
Heat sink
Fig.4
Rear panel
Fig.5
A
Bottom cover
Joint c
Bottom cover
Joint b
Rear panel
.6
Fi
Joint c
Joint d
1-5
KD-S783M
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 and the bottom cover.
1.
Remove the screw B, the four screws C and the
three screws D attaching the rear bracket on the
back of the body. Remove the rear panel.
2.
Remove the two screws E attaching the main board
on the bottom of the body. Disconnect connector
CN501 on the main board in the direction of the
arrow.
D
E
C
Rear panel
C
D
Fig.7
Main board
B
C
D
E
Removing the CD mechanism section
(See Fig.9)
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.
1.
Remove the three screws F attaching the cassette
mechanism section on the back of the top chassis.
CN501
F
Fig.8
CD mechanism section
F
Fig.9
F
Top chassis
1-6
KD-S783M
g
Removing the control switch board
(See Fig.10 ~ 12)
Prior to performing the following procedure, remove
the front panel assembly.
1.
Remove the four screws G attaching the rear cover
on the back of the front panel assembly.
2.
Unjoint the eleven joints e with the front panel and
the rear cover.
3.
Remove the control switch board on the back of the
front panel.
Joint e
Front panel
G
G
Rear cover
Fig.10
Joint e
G
G
Joint e
Front panel
Joint e
Fig.11
Fi
.12
Rear cover
Control switch board
1-7
KD-S783M
<CD mechanism section>
Removing the CD mechanism control
board (See Fig.1 and 2)
1.
Unsolder 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.
Remove 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.
Disconnect 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
Shift the lock
Removing the loading motor
(See Fig.3 to 5)
Prior to performing the following procedure, remove
the CD mechanism control board.
1.
Remove the two springs f attaching the CD
mechanism assembly and the front bracket.
2.
Remove the two screws B and the front bracket
while pulling the flame outward.
3.
Remove the belt and the screw C from the loading
motor.
Loading motor
C
FD gear
f
B
Loading motor
Pull outward
Fig.2
CD mechanism control board
f
B
Front bracket
Fig.3
Front bracket
Pull outward
1-8
Fig.5
Belt
Flame
Fig.4
KD-S783M
Removing the CD mechanism assembly
(See Fig.1, 6 to 9)
Prior to performing the following procedure, remove
the CD mechanism control board and the front
bracket (loading motor).
1.
Remove the three screws D and the damper
bracket.
2.
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.
3.
Remove the CD mechanism assembly and the two
springs h attaching the flame.
4.
Remove the two screws E and both sides rear
damper brackets from the dampers. Detach the CD
mechanism assembly from the left side to the right
side.
ATTENTION:
The CD mechanism assembly can be
removed if only the rear damper
bracket on the left side is removed.
CD mechanism
h
Front bracket
CD mechanism
D
Flame
assembly
D
assembly
h
D
Damper bracket
D
A
Fig.5
e
b
Damper bracket
D
Fig.6
a
h
c
D
d
CD mechanism
control board
h
Fix plate (L)
g
Fix arm (R)
D
Fig.7
Rear damper bracket
g
Fig.8
Rear damper bracket
E
Fix plate(R)
E
Fix arm (L)
Damper
Damper
g
g
Fig.9
1-9
KD-S783M
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) and the CD mechanism assembly.
1.
Remove the two screws F and the feed motor
assembly.
Removing the pickup unit
(See Fig.10 and 11)
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.
1.
Detach the FD gear part of the pickup unit upward.
Then remove the pickup unit while pulling out the
part i of the FD screw.
Feed motor assembly
F
FD gear
Nut push spring plate
FD screw
Pickup unit
Fig.10
Part i
Part j
Pickup unit
G
Pickup mount nut
Pickup unit
ATTENTION:
2.
Remove the screw G attaching the nut push spring
plate and the pickup mount nut from the pickup unit.
Pull out the FD screw.
When reattaching the pickup unit,
reattach the part j of the pickup unit,
then the part i of the FD screw.
Removing the spindle motor
(See Fig.12 and 13)
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.
1.
Turn up the CD mechanism assembly and remove
the two springs k on both sides of the clamper arms.
Open the clamper arm upward.
2.
Turn the turn table, and remove the two screws H
and the spindle motor.
k
FD screw
Spindle motor
Fig.11
k
Fig.12
H
1-10
H
Fig.13
Adjustment method
KD-S783M
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
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
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.
EXTGS004-26P
1-11
KD-S783M
Acceleration
Flow of functional operation until TOC read
Power ON
• When the pickup correctly moves
to the inner area of the disc
Set Function to CD
• When the laser diode correctly
emits
Microprocessor
commands
FMO
TC9462 "53"
FEED MOTOR
+TERMINAL
TERMINAL
IC581 "5"
REST SW
• When correctly focused
Focus Servo Loop ON
Disc inserted
Pickup feed to the inner area
Laser emitted
Focus search
Disc rotates
RF signal eye-pattern
remains closed
Tracking loop closed
RF signal eye-pattern
opens
TOC readout
YES
YES
Microprocessor
commands
"No disc"
display
• When the disc correctly rotates
Microprocessor
commands
Spindle
motor (-)
IC581 "7"
Acceleration
Acceleration
0.5 Sec
Rough
Servo
0.5 Sec
Servo CLV
1-12
Jump to the first track
Play
Tracking Servo Loop ON
• RF signal
Rough Servo Mode
CLV Servo Mode
(ProgramArea)
CLV Servo Mode
(Lead-In Area;
Digital: 0)
Feed Section
Is the voltage output at
IC521 pin "53" 5V or 0V?
YES
Is 4V present at both
sides of the feed motor?
YES
NO
Is the wiring for IC521
(90) ~ (100) correct?
NO
Is 6V or 2V present at
IC581 "5" and "6"?
NO
YES
YES
Is 5V present at IC581
pin "11"?
YES
Check the vicinity of
IC521.
Check the feed motor
connection wiring.
NONO
KD-S783M
Check CD 9V
and 5V.
Check the feed motor.
Focus Section
When the lens is
moving:
4V
Does the S-search
waveform appear at
IC581 pins "17" and "18"?
Spindle Section
Is the disk rotated?
YES
Does the RF signal
appear at TP1?
YES
Check IC581.
NO
YES
NO
NO
Check the circuits in
the vicinity of IC581
pins "15" ~ "18".
Check the pickup and
its connections.
Is 4V present at IC581
pins "7" and "8" ?
Check the spindle motor
and its wiring.
YES
YES
NO NO
Is 4V present at IC521
pin "55" ?
YES
Check the vicinity of
IC581.
Check IC501 and
IC521.
Is the RF waveform at TP1
distorted?
YES
Proceed to the Tracking
section
Tracking Section
When the disc is rotated
at first:
Is the tracking error signal
output at IC501 "12"?
Check IC521.
NO
Approx. 1.2 V
YES
Check the circuits in the
vicinity of IC501 "19" ~
"24" or the pickup
Check the circuit in the
vicinity of IC501 pins
"2" ~ "12".
YESYES
Check the pickup and
its connections.
1-13
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.
Is RF output
1.0 0.35Vp-p?
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.
NO
Replace it.
Replacement of laser pickup
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.
1-14
Play a disc.
Check the eye-pattern at TP1.
Finish.
Description of major ICs
TB2118F-X (IC31) : PLL
1. Terminal layout
2423222120191817161514
KD-S783M
13
2. Block diagram
osc
2
1
XO
24
XI
FM VCO
AMVCO
IFC
CE
DIN
DOUT
DIMM
15
16
13
3
4
5
6
123456789
Buff.
ON/OFF
OSC circuit
AMP
AMP
AMP
Serial
Interface
101112
Reference Counter
Prescaler
20-bit BINARY COUNTER
Resistor 1
Resistor 2
I/O PORT
Swallow counter
Phase
Comparator
4-bit
12-bit
Programmable counter
22-bit
40bit shift register
OUTPUT PORT
Constant
power supply voltage
switch
Vdd
switch
Vcc
AM CP.
20
+
+
-
REG.
22
19
vt
18
FM cp
3. Pin function
Pin
Symbol I/O Function
No.
XOUT
10
11
12
1
2
3
4
5
6
7
8
9
OSC
CE
DI
CK
DOUT
SR
I/01
I/02
OUT1
OUT2
VDD2
Crystal oscillator pin
O
Non connect
Chip enable input
I
Serial data input
I
Clock input
I
Serial data output
O
Register control pin
O
I/O ports
I/O
I/O ports
I/O
Non connect
Non connect
Single power supply for REF. frequency block
-
7
SL
8
9
I/O -2I/O -1
10 11
12
out-2out-1
vdd2
Pin
Symbol I/O Function
No.
IFC
13
VDD
14
FMIN
15
AMIN
16
DGND
17
FMCP
18
VT
19
AMCP
20
VCC
21
RF
22
AGND
23
XIN
24
17
14
IF signal input
I
Power pins for digital block
FM band local signal input
I
AM band local signal input
I
Connect to GND (for digital circuit)
Charge pump output for FM
O
Tuning voltage biased to 2.5V.
Charge pump output for AM
O
Power pins for analog block
Ripple filter connecting pin
I
Connect to GND (for analog circuit)
Crystal oscillator pin
I
21
23
a-gnd
vccd-gndvdd
1-15
KD-S783M
TA2147F-X (IC521) : RF amp.
1.Terminal layout
2.Block diagram
VRO
FEO
FEN
RFRP
RFRPIN
RFGO
RFGC
AGCIN
RFO
RFN
13GVSW
14
15
16
17
18
19
20
21
22
23
10pF
40k
30k
20k 20k
20k
20k
BOTTOM
3k
15k
50 A
12k
12k
PEAK
20k
180k
40pF
20k
20k
PEAK
1.3V
240k
180k
40k
240k
15pF
15pF
40pF
60k
40k
60k
50k
2k
20 A
20k
60 A
50k
14k
k
1
80k
x0.5
x0.5
80k
20k
20k
15k
x2
x2
1k
2k
1.75k
10pF
12 RFDC
11
TEO
10
TEN
TEBC
9
8
SEL
7
LDO
MDI
6
5
TNI
4
TPI
3
FPI
2
FNI
1-16
GND
24
3k
1
Vcc
3.Pin function
KD-S783M
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
Symbol
Vcc
FNI
FPI
TPI
TNI
MDI
LDO
SEL
TEBC
TEN
TEO
RFDC
GVSW
I/O
I
I
I
I
I
O
I
I
I
O
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.
APC
circuit
GND OFF
HIZ
Vcc
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
Connected to Vcc
through 1k resistor
Control signal output
ON
Control signal output
ON
LDOSEL
14
15
16
17
18
19
20
21
22
23
24
VRO
FEO
FEN
RFRP
RFRPIN
RFGO
RFGC
AGCIN
RFO
RFN
GND
ModeGVSW
GND
HIZ
Vcc
Reference voltage (VRO) output pin *VRO = 1/2 Vcc when Vcc = 3.3V
O
Focus error signal generation amp output pin
O
Focus error signal generation amp negative-phase input pin
I
Signal amp output pin for track count
O
Combining RFRP signal TEO signal with TC9490F/FA configures tracking
search system.
Signal generation amp input pin for track count
I
RF signal amplitude adjustment amp output pin
O
RF amplitude adjustment control signal input pin
I
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
I
RF signal generation amp output pin
O
RF signal generation amp input pin
I
GND pin
-
CD-RW
CD-DA
CD-DA
1-17
KD-S783M
F
LA4743K (IC301) : Power amp
1.Block diagram
IN 1
TA B
IN 2
+
0.22 F
+
0.22 F
11
1
12
Vcc 1/2 Vcc 3/4
6 20
-
+
Protective
circuit
-
+
2200 F 0.022
+
9
7
+
OUT 1+
OUT 1-
PWR GND1
8
+
OUT 2+
5
-
OUT 2-
3
PWR GND2
2
ST BY
R.F
47 F
IN 3
PRE GND
IN 4
+5V
ST ON
+
0.22 F
N.C
+
0.22 F
4
Stand by
Switch
Mute
10
+
Ripple
Filter
Mute
22
circuit
3.3 F
+
15
-
+
-
17
19
10K
+
OUT 3+
OUT 3-
Low Level
Mute ON
25
18
21
23
PWR GND3
OUT 4+
OUT 4-
13
14
Protective
circuit
-
+
+
-
1-18
ON TIME C
22 F
Muting &
16
+
ON Time Control
Circuit
PWR GND4
24
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