JVC MX-KB4 Service Manual

Page 1
SERVICE MANUAL
COMPACT COMPONENT SYSTEM
MB19620045
MX-KB4
Area suffix
J ---------------------------- U.S.A. C ------------------------- Canada
STANDBY/ON
SLEEP
AUX
FM /AM
FM MODE
CD
CD1CD2CD
3
PROGRAM/RANDOM
REPEAT
TAPE
TAPE
A
B
SOUND
VOLUME
MODE
FADE
MUTING
RHYTHM AX
REMOTE CONTROL
CA-MXKB4SP-MXKB4 SP-MXKB4
TABLE OF CONTENTS
2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21
COPYRIGHT © 2004 VICTOR COMPANY OF JAPAN, LIMITED
No.MB196
2004/6
Page 2
SPECIFICATION
Amplifier Output Power 180 W per channel, min. RMS, driven into 6 at 1kHz, with no more
than 10% total harmonic distortion
Input Sensitivity/Impedance (1 kHz) AUX IN:400 mV/50 k Speaker terminals 6 - 16 Phones 32 - 1 k
Cassette Deck Frequency Response 15 mW/ch output into 32
Type I (NORMAL) 63 Hz - 12 500 Hz
Wow And Flutter 0.15% (WRMS)
CD Player CD Capacity 3 CDs
Dynamic Range 85 dB
Signal-To-Noise Ratio 85 dB
Wow And Flutter Unmeasurable
Tuner FM Tuner Tuning Range:87.5 MHz - 108.0 MHz
AM Tuner Tuning Range:530 kHz - 1 710 kHz
Unit Dimensions 270 mm × 306 mm × 456 mm (W/H/D) (10-11/16" × 12-1/16" × 18")
Mass Approx. 8.6 kg (19.0 lbs)
Speaker Specifications SP-MXKB4 (each unit)
Power Specifications Power Requirements AC 120 V , 60 Hz
Type 3-way bass-reflex type
Speaker Unit Woofer:20 cm (7-7/8") cone × 1
Mid:5cm (2") cone × 1 Tweeter:2 cm (13/16") dome × 1
Power Handling Capacity 180 W
Impedance 6
Frequency Range 45 Hz - 22,000 Hz
Sound pressure level 87 dB/W·m
Dimensions 257 mm × 321 mm × 261 mm (W/H/D) (10-1/8" × 12-11/16" × 10-5/16")
Mass Approx. 4.9 kg (10.9 lbs)
Power Consumption 150 W (power on mode)
22 W (in Standby mode)
Design and specifications are subject to change without notice.
1-2 (No.MB196)
Page 3
SECTION 1
PRECAUTION

1.1 Safety Precautions

(1) This design of this product contains special hardware and
many circuits and components specially for safety purpos­es. For continued protection, no changes should be made to the original design unless authorized in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Services should be per­formed by qualified personnel only.
(2) Alterations of the design or circuitry of the product should
not be made. Any design alterations of the product should not be made. Any design alterations or additions will void the manufacturers warranty and will further relieve the manufacture of responsibility for personal injury or property damage resulting therefrom.
(3) Many electrical and mechanical parts in the products have
special safety-related characteristics. These characteris­tics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by us­ing replacement components rated for higher voltage, watt­age, etc. Replacement parts which have these special safety characteristics are identified in the Parts List of Ser­vice Manual. Electrical components having such features are identified by shading on the schematics and by ( ) on the Parts List in the Service Manual. The use of a substitute replacement which does not have the same safety charac­teristics as the recommended replacement parts shown in the Parts List of Service Manual may create shock, fire, or other hazards.
(4) The leads in the products are routed and dressed with ties,
clamps, tubings, barriers and the like to be separated from live parts, high temperature parts, moving parts and/or sharp edges for the prevention of electric shock and fire hazard. When service is required, the original lead routing and dress should be observed, and it should be confirmed that they have been returned to normal, after reassem­bling.
(5) Leakage shock hazard testing
After reassembling the product, always perform an isola­tion check on the exposed metal parts of the product (an­tenna terminals, knobs, metal cabinet, screw heads, headphone jack, control shafts, etc.) to be sure the product is safe to operate without danger of electrical shock.Do not use a line isolation transformer during this check.
• Plug the AC line cord directly into the AC outlet. Using a "Leakage Current Tester", measure the leakage current from each exposed metal parts of the cabinet, particular­ly any exposed metal part having a return path to the chassis, to a known good earth ground. Any leakage cur­rent must not exceed 0.5mA AC (r.m.s.).
• Alternate check method Plug the AC line cord directly into the AC outlet. Use an
AC voltmeter having, 1,000 per volt or more sensitivity in the following manner. Connect a 1,500 10W resistor paralleled by a 0.15µF AC-type capacitor between an ex-
posed metal part and a known good earth ground. Measure the AC voltage across the resistor with the AC
voltmeter. Move the resistor connection to each exposed metal part, particularly any exposed metal part having a return path to the chassis, and measure the AC voltage across the resistor. Now, reverse the plug in the AC outlet and repeat each measurement. Voltage measured any must not exceed 0.75 V AC (r.m.s.). This corresponds to 0.5 mA AC (r.m.s.).
AC VOLTMETER (Having 1000 ohms/volts, or more sensitivity)
0.15 F AC TYPE
Place this probe on
1500 10W
Good earth ground

1.2 Warning

(1) This equipment has been designed and manufactured to
meet international safety standards.
(2) It is the legal responsibility of the repairer to ensure that
these safety standards are maintained.
(3) Repairs must be made in accordance with the relevant
safety standards.
(4) It is essential that safety critical components are replaced
by approved parts.
(5) If mains voltage selector is provided, check setting for local
voltage.

1.3 Caution

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.

1.4 Critical parts for safety

In regard with component parts appearing on the silk-screen printed side (parts side) of the PWB diagrams, the parts that are printed over with black such as the resistor ( ), diode ( ) and ICP ( ) or identified by the " " mark nearby are critical for safety. When replacing them, be sure to use the parts of the same type and rating as specified by the manufacturer. (This regulation dose not Except the J and C version)
each exposed metal part.
(No.MB196)1-3
Page 4

1.5 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.
1.5.1 Grounding to prevent damage by static electricity
Static electricity in the work area can destroy the optical pickup (laser diode) in devices such as laser products. 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
1M
Conductive material (conductive sheet) or iron palate
(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.

1.6 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.

1.7 Attention when traverse unit is decomposed

*Please refer to "Disassembly method" in the text for the pickup unit.
• Apply solder to the short land sections before the flexible wire is disconnected from the connecto on the servo board. (If the flexible wire is disconnected without applying solder, the pickup may be destroyed by static electricity.)
• In the assembly, be sure to remove solder from the short land sections after connecting the flexible wire.
CD changer
unit
1-4 (No.MB196)
Flexible cable
Soldering
Page 5

1.8 Importance administering point on the safety

Caution: For continued protection against risk of fire, replace only with same type 3.5A/125V for F901 and 1.6A/250V for F902. This symbol specifies type of fast operating fuse.
Precaution: Pour eviter risques de feux, remplacez le fusible de surete de F901 comme le meme type que 3.5A/125V et 1.6A/250V pour F902. Ce sont des fusibles suretes qui functionnes rapide.
^
(No.MB196)1-5
Page 6
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.
1-6 (No.MB196)
Page 7
SECTION 3
DISASSEMBLY

3.1 Disassembly of the main blocks of the set

Replacement of the fuses and the power IC
3.1.1 Replacing the fuses (See Fig.1)
• Prior to performing the following procedure, remove the left
side board. (1) Replace the fuses inside.
Caution:
Be sure to use fuses with the specified ratings.
3.1.2 Replacing the power IC (See Fig.2)
• Prior to performing the following procedure, remove the top
cover. (1) Remove the two screws A from the heat sink between the
power IC.
(2) Remove the solder fixing the power IC.
Fuse (F902)
1.6A 250V
Fig.1
W
Fuse (F901)
3.5A 125V
A
3.1.3 Replacing the heat sink cover (See Fig.3)
(1) Remove four screws B from the rear panel. (2) Pull the heat sink cover outward.
Fig.2
B
Fig.3
(No.MB196)1-7
Page 8
3.1.4 Removing the top cover (See Fig.4 and 5)
(1) Remove six screws C that retain the top cover from the
panel rear of the body.
(2) Remove six screws D that retain the top cover from the two
sides of the body.
(3) Remove the top cover from the body by lifting it toward the
rear.
Top cover
C
CC
Fig.4
Right Front panel assembly
D
D
Left Front panel assembly
D
D
Fig.5
1-8 (No.MB196)
Page 9
3.1.5 Removing the CD changer unit
(See Fig.6 to 9)
• Prior to performing the following procedures, remove the top
cover.
Caution:
Although the CD mechanism unit can be removed without re­moving the CD tray panel, it is still recommended to remove it in order to prevent damage. a. From the front panel side of this set, push in the sections
marked with arrows and pull out the CD tray toward the front.
b. Remove the CD tray panel by pushing both of its extremi-
ties upward in the direction of the arrows. c. Push the CD tray deep into the set. (1) Disconnect the cord wires from the CD board CN703
.
CN203
and
(2) From the rear of the set, remove two screws E, two screws
F and four screws G on the front panel left and right side.
(3) Handle the CD changer unit rear, take out the unit.
CD tray panel
E
Antenna terminal
F
Fig.8
Fig.6
CD tray panel
Fig.7
G
Fig.9
(No.MB196)1-9
Page 10
3.1.6 Removing the front panel assembly (See Fig.10 to 11)
• Prior to performing the following procedures, remove the top
cover.
• Also remove the CD changer unit.
(1) Disconnect the parallel wire and the cord wire from the con-
nectors CN701
(2) Remove one screws H retaining the front panel assembly
onto the bottom of the body.
(3) Remove two screws I on the left and right side of the set re-
taining the panel front from the bottom and then remove then GND lug b that comes from the amp and supply board.
(4) Disengage the claws c on both sides of the front panel as-
sembly and then remove the assembly.
, CN101 on the power amp. PCB.
H
Fig.10
a
Fig.11
GND lugGND lug
b
Claw
c
1-10 (No.MB196)
Page 11

3.2 Disassembly of units and assembly inside this set

3.2.1 Removing the Main board
(See Fig.12 to 13)
• Prior to performing the following procedures, remove the top
cover.
• Also remove the CD changer unit.
(1) Disconnect the wires from CN603A
on the Main board, which is located on the back side of the CD changer unit.
(2) The four screws J that retain the CD board should be re-
moved.
(3) Remove the CD board by pulling it toward the side where
the CN601
(4) Using solder, short the CD pickup to connect to short
round.
Caution:
After re-connecting the wires, be sure to remove the shorting solder from the GND connection.
(5) Disconnect the card wire from the connector CN601
Main board and then remove the Main board.
is located.
, CN603B and CN604
on the
CD PCB
J
PAIN PCB
J
Fig.12
CN601
J
Short round
Fig.13
(No.MB196)1-11
Page 12
3.2.2 Removing the CD changer mechanism assembly (See Fig.14 to 15)
• Also remove the CD changer unit.
(1) Turn the CD changer mechanism cover base and remove
the screws d connecting the unit to the CD changer mech­anism assembly.
(2) Removing four screws e retaining the CD mechanism hold-
er assembly.
Caution:
When replacing the CD changer mechanism assembly, be sure not to mistake the positions of the silver color and copper color spring.
CD changer unit
CD changer mechanism assembly
d
Fig.14
e
( Green color )
e
( Green color )
Fig.15
e
( Red color )
e
( Red color )
1-12 (No.MB196)
Page 13
3.2.3 Removing the CD pickup
r
(See Fig.16)
• Prior to performing the following procedures, remove the top
cover.
• Also remove the CD changer unit.
• Also remove the CD changer mechanism.
(1) Widen the section f. (2) While keeping the section f wide open, push the section g
in the direction of the arrow to remove the shaft, and then remove the CD pickup.
CD pickup
f
3.2.4 Replacing the loading motor and rotor belt of the CD changer
(See Fig .17)
• Prior to performing the following procedures, remove the top
cover.
• Also open the CD changer tray.
(1) Remove the two screws L retaining the CD changer tray
loading motor.
(2) Remove the two screws M retaining the gear plate and take
it out, after remove the rotor belt from the pulley.
g
Shaft
Fig.16
M
L
3.2.5 Replacing the CD turn table and removing the motor
(See Fig.18 )
• Prior to performing the following procedures, remove the top
cover.
• Also remove the CD changer unit.
(1) Remove the one screws retaining the CD (Turn table). (2) Remove the two screws retaining the stopper brackets on
both sides of the CD changer unit.
(3) Remove the stopper brackets from both sides of the CD
changer unit.
(4) Pull out the CD tray from the CD changer unit, all the way
and lift the tray to remove.
(5) Remove the gear and after push out the tray motor locker
and pull out the tray motor from the CD tray.
Fig.17
Turn table motor
Motor locker
Obligue gea
Fig.18
(No.MB196)1-13
Page 14
3.2.6 Removing the cassette deck mechanism (See Fig.19)
• Prior to performing the following procedures, remove the top
cover.
• Also remove the CD changer unit.
• Also remove the front panel assembly.
(1) Remove six screws Z retaining the cassette deck mecha-
nism.
3.2.7 Removing the Key open board & the Key rec board (See Fig.20)
• Prior to performing the following procedures, remove the top
cover.
• Also remove the CD changer unit.
• Also remove the front panel assembly.
(1) Remove two screws P that retains the Key open board. (2) Remove three screws L that retains the Key REC board.
Key open board
P
Front panel assembly
Z
Z
Fig.19
Front panel assembly
Front panel assembly
L
3.2.8 Removing the Display board (See Fig.21)
• Also remove the CD changer unit.
• Also remove the front panel assembly.
(1) Remove six screws Q that retain the Display board from the
back of the front panel unit.
Key REC board
Fig.20
Display PCB
Q
Fig.21
Q
1-14 (No.MB196)
Page 15
3.2.9 Removing the Switch board and sound mode and CD function switch board
y
(See Fig.20 to 23)
• Prior to performing the following procedures, remove the top
cover.
• Also remove the CD changer unit.
• Also remove the front panel assembly.
(1) Pull out the volume control knob from the front of the front
panel assembly.(Fig.22) (2) Remove six screws Q retaining the front panel assembly. (3) Remove the Control/FL board. (4) Remove eleven screws retaining the Switch (key 1)
board.(Fig.20) (5) Remove two screws S retaining the sound mode and CD
function (key 2) switch board.(Fig.21)
Volume knob
Front panel assembl
Fig.22
Front panel assembly
Volume shaft
Fig.23
(No.MB196)1-15
Page 16
3.2.10 Removing the cassette deck main motor, and replacing the main belts
r
(See Fig.19, 24 and 25)
• Prior to performing the following procedures, remove the top cover and both sides board.
• Also remove the CD changer unit.
• Also remove the front panel assembly. (1) Remove six screws Z retaining the cassette deck mecha-
nism. (Fig.19) (2) Remove the cassette deck mechanism. (3) Remove two screws t retaining the main motor from the
front side of the cassette deck.
Caution:
After attaching the main motor, check the orientation of the motor and the polarity of the wires.
(4) From the backside of the cassette deck, remove the main
motor and two main belts.
Caution:
The lengths of the cassette A(playback only) and cas­sette B(record/play) main belts are different. When at­taching the main belts, use the longer belt for cassette A.
Cassette deck mechanism (Back side)
Cassette deck mechanism (Front side)
t
Fig.24
Cassette deck main moto
3.2.11 Removing the leaf switches of the cassette deck mechanism (See Fig. 19 and 26)
• Prior to performing the following procedures, remove the top
cover and both sides board.
• Also remove the CD changer unit.
• Also remove the front panel assembly.
(1) Remove the six screws Z that retain the cassette deck
mechanism. (Fig.19) (2) Remove the cassette deck mechanism. (3) Turn the cassette deck mechanism upside down. (4) Remove the solder from around the leaf switches. (5) Pull out the leaf switches from the front side of the cassette
deck mechanism.
Main belt (For B cassette)
Fig.25
Solder side of leaf switch
Cassette deck mechanism
Fig.26
Main belt (For A cassette)
(Back side)
1-16 (No.MB196)
Page 17
3.2.12 Removing the cassette deck heads (See Fig. 19 and 27)
• Prior to performing the following procedures, remove the top
cover and both sides board.
• Also remove the CD changer unit.
• Also remove the front panel assembly.
(1) Remove six screws Z that retain the cassette deck mecha-
nism. (Fig.19)
(2) Remove the cassette deck mechanism and place it so that
the front side faces up.
(3) Remove the solder from the bottom side of the head termi-
nal and disconnect the wire. (4) Remove screws U that retains the head. (5) Remove screws V that retains the head. (6) Hold the head and slide it in the direction of the arrow to re-
move it.
3.2.13 Removing the 3-pin regulator and bridge diode (See Fig. 28)
• Prior to performing the following procedures, remove the top
cover and both sides board. Remove two screws A that connect the heat sink. (1) Remove two screws A that connect the heat sink. (2) Remove two screws W that connect the heat sink. (3) Remove the solder fixing the the 3-pin terminal regulator
, Q608.
Q604
(4) Remove the solder fixing the 4-pin bridge diode (D614
D615).
PB Head
Cassette deck mechanism (Front side)
V
U
VU
REC/PB Head
Fig.27
W
A
,
Fig.28
(No.MB196)1-17
Page 18
3.2.14 Removing the Power amp and Supply board and the Power trans board
A
(See Fig. 3, 29 to 31)
• Prior to performing the following procedures, remove the top cover and CD changer unit. (1) Remove four screws B from the rear panel. (Fig.3) (2) Pull the heat sink cover outward. (3) Remove four screws AA from the rear panel between the
heat sink holder.
(4) Remove four screws YY that retains the rear panel, and
then remove the rear panel.
(5) Disconnect the parallel wires from the connectors FW951
on the Power trans board.
(6) Remove screws Z that retain the Power amp and Supply
board and then remove the assembly. (7) Remove the clamp of AC power cord from the chassis. (8) Remove four screws that retain the Power trans board and
then remove the assembly.
Fuse (F902)
1.6A 250V
A
Fuse (F901)
3.5A 125V
Fig.29
Rear panel
YY
Fig.30
Power amp and supply board
Chassis
Z
Fig.31
Clamp
1-18 (No.MB196)
Page 19
SECTION 4
ADJUSTMENT

4.1 Measurement Instruments Required for Adjustment

(1) Low frequency oscillator
This oscillator should have a capacity to output 0dBs to
600 at an oscillation frequency of 50Hz-20kHz.
(2) Attenuator impedance : 600
(3) Electronic voltmeter (4) Frequency counter (5) Wow & flutter meter (6) Test tape
VT712 : For Tape speed and wow flutter ( 3kHz) VT703 : For Head angle (10kHz)
(7) Blank tape
TYPE l : AC-225 TYPE ll : AC-514
(8) Torque gauge
For play and back tension forward; TW2111A Reverse; TW2121A Fast Forward and Rewind; TW2231A
(9) Test disc
CTS-1000(12cm) GRG-1211(8cm)
(10) Jitter meter

4.2 Measurement conditons

Power supply voltage AC 120V ~, 60Hz
Measurement output terminal
4.2.1 Radio Input signal
AM modulation frequency 400Hz
Modulation factor 30%
FM modulation frequency 1 kHz
Frequency displacement 22.5kHz
Speaker out TP101 (Measuring for TUNER/ DECK/CD)
Dummy load 6
4.2.2 Standard measurement position of volume and switch
Power Standby
(Light STANDBY Indicator)
Sound Turbo,A,BASS EX OFF
Sound mode OFF
Main VOL. 0 Minimum
Travers mecha set position Disc 1
Precautions for measurement
(1) Apply 30pF and 33k to the IF sweeper output side and
0.082µ F and 100k in series to the sweeper input side.
(2) The IF sweeper output level should be made as low as
possible within the adjustable range.
(3) Since the IF sweeper is a fixed device, there is no need
to adjust this sweeper.
(4) Since a ceramic oscillator is used, there is no need to
perform any MIX adjustment.
(5) Since a fixed coil is used, there is no need to adjust the
FM tracking.
(6) The input and output earth systems are separated. In
case of simultaneously measuring the voltage in both of the input and output systems with an electronic voltmeter for two channels, therefore, the earth should be connect­ed particularly carefully.
(7) In the case of BTL connection amp., the minus terminal
of speaker is not for earthing. Therefore, be sure not to connect any other earth terminal to this terminal. This system is of an BTL system.
(8) For connecting a dummy resistor when measuring the
output, use the wire with a greater code size.
(9) Whenever any mixed tape is used, use the band pass fil-
ter (DV-12).
(No.MB196)1-19
Page 20

4.3 Arrangement of adjusting positions

Cassette deck mechanism (Front side)
4.3.1 Tape recorder section
Items
Cassette Head Azimuth Alignments
Measurement
conditions
Test tape : VT703 (10kHz) Measurement output terminal : Left and Right speaker output (6-ohm loaded) or Headphone Output (32-ohm loaded)
PB Head (Deck-A)
Head azimuth screw
(Forward side)
Head azimuth screw
1. Playback the test tape VT703 (10KHz) or equivalent.
2. Adjust the head azimuth screw to obtain maximum output and both output of L / R is in 3dB.
3. Put on the screw lock paint after alignments.
Head azimuth screw
(Forward side)
(Reverse side)
Measurement method
REC/PB Head (Deck-B)
Head azimuth screw
(Reverse side)
Standard
values
Maximum output
Adjusting positions
Adjust the head azimuth screw only when the head has been changed.
Recording Bias Frequency Alignment
Test tape : TYPE AC-514 Measurement output terminal
1. Insert the recording tape in deck-B.
2. Starting the recording.
3. Adjust the oscillation frequency to 80KHz+/-3KHz by
core of Oscillation coil of L301. : Erase head terminal (CN308 8-Pin)
4.3.2 Tuner section
Items
AM Tracking Alignments
Measurement
conditions
Input signal : 530kHz 600kHz Adjustment point : Antenna coil (L2)
1. Set the Signal Generator signal to 530KHz the feed
to Loop Antenna.
2. Receiving the signal and the adjust the OSC coil (L2)
obtain the V.T is 1.40V +/-0.05V.
3. Change the receiving frequency to 600KHz (603KHz).
4. Adjust the Antenna coil ( L2 ) obtain maximum
sensitivity. (Adjust the SSG output to out of AGC range.)
AM IFT Alignments
Input signal : 530kHz Adjustment point : IFT (T1)
1. Set the receiving frequency to 530KHz.
2. Feed the 450KHz signal to AM antenna input.
3.Adjust the IFT Block T1 obtain to maximum output.
(Adjust the SSG output to out of AGC range.)
Note: The adjustment of CD section is not required.
Measurement method
80kHz+/-3kHz
Standard
values
V. T : 1.40V+/-0.05V
Maximum sensitivity
Maximum output
Use the High­Impedance Probe or Frequency counter input.
Adjusting positions
Adjust the OSC coil only when the AM coil block has been changed.
Adjust the IFT only when the IFT block has been changed.
1-20 (No.MB196)
Page 21
TROUBLESHOOTING

5.1 Flow of functional operation until TOC read

Power ON
Play Key
SECTION 5
Slider turns REST SW ON.
Automatic tuning of TE offset
Check Point
Confirm that the voltage at the pin5 of CN702 is "H"\"L"\"H".
Tracking error waveform at TOC reading
Approx.3sec
Tracking servo off states
Automatic measurement of TE amplitude and automatic tuning of TE balance
VREF
pin 20 of IC611(TE)
Approx
0.3V
Disc states to rotate
Tracking servo on states
Disc to be braked to stop
TOC reading finishes
500mv/div 2ms/div
Fig-1
Laser ON
Detection of disc
Automatic tuning of Focus offset
Automatic measurement of Focus S-curve amplitude
Disc is rotated
Focus servo ON
(Tracking servo ON)
Automatic measurement of
Tracking error amplitude
Automatic tuning of Tracking error balance
Check that the voltage at the pin10 of IC701 is + 0V?
Confirm that the Focus error S-cuve signal at the pin31 of IC701 is approx.2Vp-p
Confirm that the signal from pin26 IC701 is 0V as a accelerated pulse during approx.400ms.
Confirm the waveform of the Tracking error signal. at the pin 29 of IC701 (R729) (See fig-1)
Automatic tuning of Focus error balance
Automatic tuning of Focus error gain
Automatic tuning of Tracking error gain
TOC reading
Play a disc
Confirm the eys-pattern at the lead of Pin 2 of IC 701
(No.MB196)1-21
Page 22

5.2 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.
• The level of RF output (EFM output : ampli tude of eye pattern) will below.

5.3 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)
Is the level of RFOUT under
0.48V 0.1Vp-p?
NO
Replace it.
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.
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
Pin 2 of IC 701
Finish.
1-22 (No.MB196)
Page 23
(No.MB196)1-23
Page 24
VICTOR COMPANY OF JAPAN, LIMITED
AV & MULTIMEDIA COMPANY AUDIO/VIDEO SYSTEMS CATEGORY 10-1,1chome,Ohwatari-machi,Maebashi-city,371-8543,Japan
(No.MB196)
Printed in Japan
WPC
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