JVC MXG-500-UW Service manual

SERVICE MANUAL
COMPACT COMPONENT SYSTEM
MX-G500
STANDBY/ON
SLEEP
AUX
FM/AM
RM–SMXG500 U REMOT
12
456
78
10
T
APE
CD
MX-G500
Area suffix
UY ---------------- Argentina
STANDB
Y
STANDBY/ON
3
CD
MX-G
500
3
SUBWOOFER
L
EVE
L
S
O
UND
M
O
DE
9
FM MODE
+10
O
ECH
KARAOKE
FADE T
APE A/B
MUTIN
G
DISC SKIP
+
VOL
UME
VOL
UME
E CONTROL
EXTENDED SUPER BASS
AUX
PHONES
FM
CD
/ AM
PROGRAMRANDO
M
R
EPEAT
REC STAR
T
C
D REC
DUBBING
/STO
P
START
FULL - LOGIC CONTROL
T
APE
A
DISPLAY
TAPE BTAPE
COMPU PLAY CONTROL
CD SYNCHRO RECORDIN
SP-MXG500 SP-MXG500CA-MXG500
DISC CHANGE
3
2
1
D
D
D
C
C
C
CD-R/RW PLAYBAC K
SOUND
M
ODE
CLOCK /TIMER
MIC
LEVEL
MIN MAX
SUBWOOFER
LEVEL
MIC
G
Contents
Safety Precautions Preventing static electricity Important for laser products Disassembly method Wiring connection Adjustment method
1-2 1-3 1-4 1-5 1-19 1-20
Flow of functional operation until TOC read Maintenance of laser pickup Replacement of laser pickup Trouble shooting Description of major ICs
COPYRIGHT 2002 VICTOR COMPANY OF JAPAN, LTD.
1-24 1-25 1-25 1-26 1-29~44
No.21126
Sep. 2002
MX-G500
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 manufacturer`s 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 re-assembling.
5. Leakage currnet check (Electrical shock hazard testing) After re-assembling 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 ohms per volt or more sensitivity in the following manner. Connect a 1,500 10W resistor paralleled by a 0.15 F AC-type capacitor between an exposed 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 meausre 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.).
0.15 F AC TYPE
1500 10W
Good earth ground
AC VOLTMETER (Having 1000 ohms/volts, or more sensitivity)
Place this probe on each exposed metal part.
!
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 m ust 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.
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.
In regard with component parts appearing on the silk-screen pr inted 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.
(This regulation does not correspond to J and C version.)
1-2
Preventing static electricity
MX-G500
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
In the equipment which uses optical pick-up (laser diode), optical pick-up is destroyed by the static electricity of the work environment. 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 (conductive sheet) or iron plate
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
Attention when CD mechanism assembly is decomposed
*Please refer to "Disassembly method" in the text for pick-up and how to detach the CD mechanism assembly.
1. Remove the CD changer unit.
2. Remove the CD changer mechanism.
3. Solder is put up before the card wire is removed from the pickup unit connector on the CD mechanism assembly. (When the card wire is removed without putting up solder, the CD pick-up assembly might destroy.)
4. Please remove solder after connecting the card wire with the pickup unit connector when you install picking up in the substrate.
Card wire
Picup unit connector
Soldering
Fig.2
CD changer unit
Fig.1
Card wire
Picup unit connector
CD changer mechanism
1-3
MX-G500
Important for laser products
1.CLASS 1 LASER PRODUCT
2.DANGER : Invisible laser radiation when open and inter
lock failed or defeated. Avoid direct exposure to beam.
3.CAUTION : There are no serviceable parts inside the Laser Unit. Do not disassemble the Laser Unit. Replace the complete Laser Unit if it malfunctions.
4.CAUTION : The compact disc player uses invisible laser radiation and is equipped with safety switches which prevent emission of radiation when the drawer is open and the safety interlocks have failed or are de feated. It is dangerous to defeat the safety switches.
5.CAUTION : If safety switches malfunction, the laser is able to function.
6.CAUTION : Use of controls, adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure.
!
Please use enough caution not to see the beam directly or touch it in case of an adjustment or operation check.
Position of labels
CLASS 1 LASER PRODUCT
WARNING LABEL
1-4
MX-G500
Disassembly method
Removing the metal cover (See Fig.1)
1.
Remove the three screws A attaching the metal cover on the back of the body.
2.
Remove the six screws B attaching the metal cover on both sides of the body.
3.
Remove the metal cover from the body by lifting the rear part of the cover.
ONE POINT
How to eject the CD tray (see fig.2)
Although it will end if the OPEN/CLOSE button is pushed when a power supply can be taken, when that is not right, CD tray will be opened manually. Turn the loading pulley gear at the bottom of the CD changer unit as shown in Fig.2 and draw the CD tray toward the front.
Metal cover
A
B
(both sides)
Fig.1
Loading pulley gear (See <CD changer unit>fig.1)
Removing the CD tray fitting
(See Fig. 3)
Prior to performing the following procedure, eject the CD tray.
After drawing the lower part of the tray fitting toward
1. the front, remove the five claws. Then, while moving the tray fitting upward, remove it.
Removing the CD changer unit
(See Fig.4 to 7)
Prior to performing the following procedure, remove the metal cover and CD tray fitting.
1.
Remove the card wire attached to CD changer unit on the adhesion tape.
2.
Disconnect the card wire from the connector CW105 on the CD board.
3.
Disconnect the harness from the connector RCW6 on the main board and CW107 on the CD board.
4.
Remove the two screws C attaching the CD changer unit to the rear panel.
Fig.2
Joint
CD tray fitting
Claw
Fig.3
Card wire
CD changer unit
5.
Remove the two screws D attaching the CD changer unit to both sides of the front panel assembly.
6.
Draw the CD changer unit upward from behind while pulling the rear panel outward.
Adhesion tape
Fig.4
1-5
MX-G500
CW105 CW107
Fig.5
CD board
CD changer unit
Main board
RCW6
Front panel
assembly
D
(both sides)
C
Rear panel
Fig.6
CD changer unit
Rear panel
Fig.7
Removing the front panel assembly
(See Fig.8 to 10)
Prior to performing the following procedure, remove the metal cover and CD changer unit.
1.
Disconnect the card wire from the connector FCW3 on the main board.
2.
Disconnect the harness from the connector ECW1, JCW1, JCW2 and HCW3 on the main board.
3.
Remove the screw E attaching the earth terminal extending from the cassette mechanism assembly.
4.
Remove the two screws F attaching the front panel assembly to both sides of the body.
5.
Remove the screw G attaching the main board to the front panel assembly.
6.
Remove the screw H attaching the front panel assembly to bottom of the body.
7.
Release the two joints1 and two joints2, and detach the front panel assembly toward the front.
Front panel
assembly
Joint1 (both sides)
(both sides)
FCW3
F
Main board
JCW2
ECW1
JCW1
HCW3
E
(fixing the earth wire)
Fig.8
Main board
Voice board
ACW1 ACW2
Amp. board
Front panel assembly
G
1-6
Fig.9
Joint1 (both sides)
F
(both sides)
MX-G500
)
Removing the heat sink & amp. board
(See Fig.8, 11 and 12)
Prior to performing the following procedure, remove the metal cover and CD changer unit.
1.
Disconnect the card wire from the connector ACW1 and the harness from the connector ACW2 on the amp. board.
2.
Remove the four screws I attaching the heat sink cover to the rear panel. Remove the heat sink cover.
3.
Remove the four screws J attaching the heat sink and two screws K attaching the speaker terminal to the rear panel.
4.
After moving the heat sink upward, remove the claws. Then pull out the heat sink & amp. board inward. If the voice board is removed at this time, it will be able to work comfortably.
H
Heat sink
cover
Joint2
Fig.10
(Bottom side
Rear panel
I
I
Fig.11
Removing the tuner board (See Fig.12 and 13)
Prior to performing the following procedure, remove the metal cover.
1.
Disconnect the card wire from the connector CON01 on the tuner board.
2.
Remove the two screws L attaching the tuner board to the rear panel.
Removing the rear panel (See Fig.12)
Prior to performing the following procedure, remove the metal cover, CD changer unit, heat sink & amp. board and tuner board.
1.
Remove the two screws M, screw N and three screws O attaching the rear panel.
J
Claws
Heat sink
J
O
Main board
Fig.12
CON01
Rear panel
L
M
K
Speaker terminal
N
Rear panel
Tuner board
Fig.13
1-7
MX-G500
k
Removing the main board (See Fig. 14)
Prior to performing the following procedure, remove the metal cover, CD changer unit and rear panel.
1.
Disconnect the card wire from the connector FCW3 and the harness from the connector ECW1, JCW1, JCW2 and HCW3 on the main board.
2.
Disconnect the harness from the connector PCW1 on the fuse board.
3.
Remove the screw G attaching the main board to the front panel assembly. (See Fig.9)
4.
Remove the two screws P attaching the heat sink to the bottom chassis.
5.
Pull out the voice board, if needed.
Removing the power cord (See Fig. 14)
Prior to performing the following procedure, remove the metal cover, CD changer unit and rear panel.
1.
Disconnect the power cord from the connector RCW2 on the trans. board and pull up the power cord stopper upward.
ECW1
HCW3
Fuse board
PCW1
RCW2
Power cord
Power cord
stopper
Bottom chassis
FCW3
JCW2
JCW1
Main board
Voice board
Heat sin
P
Trans. board
Fig.14
Power ICs solder point
Heat sink
Amp. board (reverse side)
Removing the power ICs
(See Fig.15 and 16)
Prior to performing the following procedure, remove the metal cover, CD changer unit and heat sink & amp. board.
1.
Unsolder the power ICs solder points.
2.
Remove the four screws Q attaching the power ICs to the heat sink.
Removing the power transformer
(See Fig .17)
Prior to performing the following procedure, remove the metal cover, CD changer unit and heat sink & amp. board.
1.
Remove the screw N attaching the trans. board to the rear panel (see fig.12).
2.
Disconnect the power cord from the connector RCW2 on the trans. board.
R
Fig.15
Q
Fig.16
Power transformer
Heat sink
Amp. board
Fuse board
PCW1
Trans. board
3.
Disconnect the harness from the connector PCW1 on the fuse board.
4.
Remove the four screws R attaching the power transformer on the bottom chassis.
1-8
Bottom chassis
RCW2
Fig.17
MX-G500
<Front panel assembly>
Prior to performing the following procedure, remove the front panel assembly.
Removing the CD switch board (See Fig.1)
1.
Disconnect the card wire from the connector UCW1 on the CD switch board.
2.
Remove the five screws A attaching the CD switch board.
Removing the front board (See Fig.1)
1.
Disconnect the card wire from the connector UCW3, UCW4, UCW5 and UCW6 on the front board.
2.
Remove the six screws B attaching the front board.
3.
Disconnect the card wire from the connector UCW2 on the front board.
Removing the headphone jack board (See Fig.3)
Prior to performing the following procedure remove the front board.
1.
You can pull out the headphone jack board.
Removing the front key board with the mic board (See Fig.2 and 3)
Prior to performing the following procedure, remove the front board.
B
UCW2 UCW3
B
UCW4
Front panel assembly (inner side)
A
CD switch board
UCW1
Front board
UCW5
UCW6
Fig.1
Sound mode knob
Volume knob Mic level knob
Subwoofer level knob
Pull out the sound mode knob, volume knob,
1. subwoofer level knob and mic level knob from front side.
Remove the twelve screws C attaching the front key
2. board.
Remove the front board releasing the two tabs1.
3. Remove the mic board releasing the two tabs2.
4. Disconnect the card wire from the connector UCW7
5. on the front key board, if needed.
Mic board
Tab2
Removing the cassette mechanism assembly (See Fig.3)
1.
Disconnect the card wire from the connector on the mecha. board.
2.
Remove the six screws D attaching the cassette mechanism assembly.
C
UCW7
Tab1
Tab1
D
Mecha.
board
D
(fixing the earth wire)
Fig.2
Front panel assembly (inner side)
Front key board
Cassette mechanism
Connector
Fig.3
C
Headphone
jack board
D
assembly
1-9
MX-G500
<CD changer unit>
Prior to performing the following procedure, remove the CD changer unit.
Removing the CD tray (See Fig.1 and 2)
1.
Turn the black loading pulley gear on the under side of the CD changer unit in the direction of the arrow and draw the CD tray toward the front until it stops.
2.
Disconnect the card wire from connector CW103 on the CD board.
3.
Push down the two tray stoppers marked a and pull out the CD tray.
Loading pulley
gear
CD changer uint (reverse side)
CD tray
CD board
CW103
Fig.1
a (Tray stopper)
Reinstall the CD tray (See Fig.3 and 4)
1.
Align the gear-cam with the gear-tray as shown fig.3, then mount the CD tray.
2.
When assembling the CD tray, take extreme care not engage with gear - synchro.
Gear-cam
Gear-convert
Gear-cam
timing point
CD tray
a
(Tray stopper)
CW103 (on the CD board)
Fig.2
Gear-tray
Gear-synchro
Gear-convert
1-10
Gear-tray
CD tray
Gear-tray
Fig.3 Fig.4
MX-G500
Removing the sensor board (See Fig.5)
Prior to performing the following procedure, remove the CD tray.
1.
Remove the screw A attaching the sensor board on the CD tray.
2.
Remove the sensor board releasing the two tabs a.
3.
Disconnect the harness from the connector CW1 on the sensor board.
Removing the turn tray motor (See Fig.6 and 7)
Prior to performing the following procedure, remove the CD tray and sensor board.
1.
Remove the screw B attaching the turn tray. Detach the turn tray from the base tray.
2.
Pull outward the tab b attaching the turn tray motor on the base tray and detach the turn tray motor.
CD tray (reverse side)
A
CW1
Tab a
Sensor board
Fig.5
Turn tray
Introductory notes: Base tray + Turn tray = CD tray
Base tray
B
Fig.6
Turn tray motor
Base tray (upper side)
Tab b
Fig.7
1-11
MX-G500
Removing the belt, the CD board and the switch board (See Fig.8 and 9)
Prior to performing the following procedure, remove the CD tray.
1.
Detach the belt from the pulley on the upper side of the CD changer unit (Do not stain the belt with grease).
2.
Disconnect the card wire from the pickup unit connector on the under side of the CD changer unit.
Attention : Solder is put up before the card wire is removed from the pick-up unit connector on the CD mechanism assembly. (When the card wire is removed without putting up solder, the CD pick-up unit assembly might destroy.)
3.
Disconnect the motor wire harness from connector on the CD board.
4.
Remove the screw C attaching the switch board and release the two tabs e attaching the switch board outward and detach the switch board.
5.
Remove the two screws D attaching the CD board. First release the two tabs f and two tabs g attaching the motor, then release the CD board.
If the tabs f and g are hard to release, it is recommendable to unsolder the two soldered parts on the motor terminal of the CD board.
Tabs e
C
Switch board
CW3
CD changer unit
Fig.8
CD board
D
Tabs g
Soldered parts
CD mechanism board
motor connecter
Pickup unit connector
Card wire
Belt
Motor
Tabs f
1-12
Soldering
Picup unit connector
Fig.9
Removing the CD mechanism holder assembly (mechanism included)
(See Fig.10 to 13)
1.
Disconnect the harness from connector on the CD mechanism board in the CD mechanism assembly on the under side of the CD changer unit. Disconnect the card wire from the pickup unit connector.
Attention : Solder is put up before the card wire is removed from the pick-up unit connector on the CD mechanism assembly. (Refer to Fig.9) (When the card wire is removed without putting up solder, the CD pick-up unit assembly might destroy.)
MX-G500
Motor connecter
CD changer unit
CD mechanism holder assembly
Pickup unit connector
2.
Remove the screw E attaching the shaft on the right side of the CD mechanism holder assembly. Pull outward the stopper fixing the shaft on the left side and remove the CD mechanism holder assembly from behind in the direction of the arrow y.
3.
Turn the CD mechanism holder assembly half around the lift up slide shaft h of the CD mechanism holder assembly until the turn table is reversed, and pull out the CD mechanism holder assembly.
Lift up slide shaft
Fig.10
E
Stopper
CD mechanism holder assembly
Fig.11
Lift up slide shaft n
CD mechanism holder assembly
Fig.13
y
CD mechanism holder assembly
Fig.12
1-13
MX-G500
<CD mechanism section>
Removing the CD mechanism holder from the CD chager unit. (Refer to "Removing the CD mechanism holder assembly" )
Removing the pickup unit (
1. Removing the cut washer on the feed gear sleeve and pull out the feed gear.
2. Remove the two screws A fixing the pickup shaft.
3. Removing the pickup unit.
Removing the motor board
1. Unsolder the motor terminal on the motor board.
2. Remove the moter board.
Removing the feed motor (
Remove the two motor fixing screws at B and removing the feed motor.
See Fig.1)
(See Fig.2)
See Fig.1)
A
Motor board
Shutter
Cut washer
B
Fig.1
Unsolder
Pickup unit
Feed motor
Shaft
A
Feed Gear
Removing the spindle motor
The spindle motor cannot be removed as a single unit. When removing the spindle motor, change the chasis and turntable together as aunit.
Spindle motor
Unsolder
Fig.2
1-14
MX-G500
<Cassette mechanism section>
Removing the record/playback mechanism.
Removing the R/P head.
1. Remove the screw A on the right side of the R/P head.(Fig.1, Fig.2)
2. Remove the screw B on the left side of the
R/P head.(Fig.1, Fig.2)
Remove the erase head.
Remove the screw C fixing the erase head.(Fig.1)
Removing the pinch roller.
1. Pull out the pinch roller by opening the pinch roller stopper outward to unlock .(Fig.3)
2. When reassembling the pinch roller, refer to fig. 4 to hook up the spring.
R/P Head
E. Head
Stoppsr
A
B
C
Fig.1
B
Pinch roller assembly
A
Spring
Pinch roller
Return spring
R/P Head
Fig.2
Pinch roller
Fig.3
Pinch roller
stopper
Pinch roller
spring
Return spring
Return spring
Fig.4
1-15
MX-G500
Removing the motor.
1. Remove the two screws D fixing the motor. Be careful to grease's splash when the drive belt comes off.(Fig.5, Fig.6)
2. Unsolder the motor terminal.(Fig.5)
Removing the mechanism board.
1.
coil terminal.(Fig.5)
2. Remove the two screws E fixing the board.(Fig.5)
capstan shaft, then remove the flywheel. When reassembling the flywheel, be sure to use new washers as they cannot be reused.(Fig.8, Fig.9)
Unsolder the four parts a on the solenoid
3. Unhook the three parts b from the board.(Fig.5)
4. Remove the mechanism board.(Fig.5)
Removing the flywheel.
Remove the cut-washers at c and d from the
Mecha.
a
Drive belt (Flat)
board
E
b
Motor
Motor
terminal
D
D
Fig.5
Drive belt
Fig.6
E
Drive belt
Motor
b
a
1-16
Sleeve
Flywheel
c
Washer
Fig.9
Sleeve
d
FR belt
Capstan
washer
Flywheel
Fig.7
FR belt
Fig.8
Capstan
washer
Flywheel
MX-G500
< Speaker section >
It is exchange in a unit. Please do not decompose as much as possible.
Removing the side panel (See Fig. 1)
1.
Remove the five screws A attaching the side panel and remove the side panel.
NOTES : It will be good to use the tool with a flat tip, since a boss's portion is pasted with adhesives. Please take care not to damage the cabinet at this time.
Removing the side speaker (See Fig. 2 and 3)
A
(long wood screw)
Side panel
A
(short wood screw)
Fig.1
Side speaker
Boss and adhesion
A(long screw)
Boss and
adhesion
Front panel
Prior to performing the following procedure, remove the side panel.
1.
Remove the four screws B attaching the side speaker.
2.
Pull out the side speaker and remove the speaker cord from the speaker terminal.
B
Fig.2
Side speaker
Speaker terminal
Fig.3
1-17
MX-G500
Removing the front panel (See Fig. 4 and 5)
Prior to performing the following procedure, remove the side panel.
1.
Remove the four bosses and remove the front panel.
Notes: It will be good to use the tool with a flat tip, since it is hard to remove. Please take care not to damage the cabinet at this time.
ONE POINT
First, it is from here. This crevice is used.
Removing the tweeter (See Fig. 5)
Prior to performing the following procedure, remove the side panel and front panel.
Remove the cord from the speaker terminal.
1. Remove the two screws C attaching the tweeter on
2. the front panel (inner side).
The tool with
a flat tip
Front panel
Fig.4
C
Tweeter
Code
Speaker terminal
Removing the woofer (See Fig. 5 and 6)
Prior to performing the following procedure, remove the side panel and front panel.
Remove the four screws D attaching the woofer and
1. remove the woofer.
Remove the cord from the speaker terminal.
2. Remove the packing.
3.
1-18
D
Woofer
Fig.5
Woofer (reverse side)
Fig.6
Boss
Front panel
Code
Speaker terminal
Packing
MX-G500
Wiring connection
Amp. board
0
0
UCW7
9
3809-001315
9
MCW1
9
Mic board
0
9
MCW2
Front key board
AH39-00246A
ACW2
ACW1
3809-001224
CD switch board
UCW1
AH39-00245A
MCW3
0
AH39-00248A
9 0
AH39-00244A
UCW2
UCW3
Front board
RCW2
PCW1
RFS3
RFS5
RFS6
UCW4
RFS4
RFS7
UCW6
UCW5
RFS8
RFS2
Power transformer
3809-001121
CD mechanism
AH39-20561P
CW2
3809-001185
AAN1
CW1
CW3
AH38-12001A
CW102
9
0
Color codes are shown below. 1 Brown 2 Red 3 Orange 4 Yellow 5 Green 6 Blue 7 Violet
0
9
8 Gray 9 White 0 Black
0
2
0
2
CW103
CW105
9
CW107
0
CD board
CW3
CW101
CW104
CW106
3809-001034
2
0
9
AH39-20025S
AH39-00096B
3809-001228
3809-001184
3809-001222
0
CW302
2
9
0
CW301
Voice board
FCW1
OCW
9
0
RCW6
FCW2
KCW2KCW1
HCW3
Tuner board
JCW1
CON01
Main board
JCW2
FCW3
ECW1
0
0
9
RW2
9
0
0
9
RW1
2
0
2
9
0
HCW2
AH39-00247A
9
Headphone J.board
AH39-00022A
9
2
0
0
9
88
9
0
AH39-20002D
9
0
9
0
9
0
9
2
0
8
2
8
2
9
1-19
MX-G500
Adjustment method
1. Tuner
Received FREQ.
Adjustment point
Output
* Adjustment Location of Tuner PCB
AM(MW) OSC Adjustment
9kHz step : 531~1602kHz 10kHz step : 530~1710kHz
MO
1~7.0V 0.5V
MAIN PCB
VT
GND
AM(MW) RF Adjustment ITEAM
594 KHz 600 KHz
MA
Maximum Output(Fig.1)
TESTER
1-20
Fig.1 OSC Voltage
FM THD Adjustment
MX-G500
SSG FREQ.
98 MHz
Adjustment point
FM DETECTOR COIL
(FM DET) Output
60 dB
Minumum Distortion (0.4% below) (Fig.2)
FM Search Level Adjustment
SSG FREQ. Adjustment
point
(SVR1)
BEACON SENSITIVITY SEMI-VR(20K
98 MHz
Output GND
FM S.S.G
FM Antenna Terminal
SET
Oscilloscope
Input
Speaker Terminal
output
Input
Distortion Meter
Fig.2 IF CENTER and THD Adjustment
28 dB
)
FM Antenna
SET
Output
28 dB(
2dB)
Adjust SVR1 so that "TUNED" of FLT is lighted (Fig.3)
*Adjust FM S.S.G level to 28dB
AM(MW) I.F Adjustment
SSG FREQ. Frequency
450 kHz 522 kHz
Adjustment point
AM IF
Maximum output (Fig.4)
FM S.S.G
GND
FM IN
Fig.3 FM Auto Search Level Adjustment
60cm
OUTPUT
AM SSG 450KHZ
AM ANT IN
20 k
AM IF
Speaker Terminal
INPUT
VTVM Oscilloscope
OUTPUT
Fig.4 AM I.F Adjustment
1-21
MX-G500
2. Cassette Deck
To adjust tape speed
Notes
1) Measuring tape: i) VT-712/MTT-111(or equivalent) (Tapes recorded with 3kHz) ii) AC-225/MTT-5512(or equivalent)
2) Connect the cassette deck to the frequency counter as in fig.1.
Cassette Deck
SPK OUT
Frequency Counter
output
Fig.1
Pre-Setup Condition
NOR
1 3KHz
SPEED Control
OUT (connected to the frequencycounter)
1) Deck 1:VT-712
2) Press PLAY SW button
To Adjust
Turn VSR1 to left and right (FRONT PCB)
3) Deck 2:Same as above
To adjust plabyback level/REC
Notes
1) Before the actual adjustment, clean the play/recording head.
2) Measuring tape : i) VT-703/MTT-114N(or equivalent 10kHz AZIMUTH control)
ii) AC-225/MTT-5512(or equivalent)
3) The cassette deck is connections as shown in fig.2.
Cassette Deck
SPK OUT
(GND)
Fig.2
VTVM
In Out
RemarkStandardPre-SetupItemStep
1%
range
Oscilloscope
1. Adjust Deck 1 Play Level
Pre-Setup Condition
AZIMUTH1 SPK OUT
(VTVM is connected to the scope)
1-22
After putting VT-703 into Deck 1
- Press FWD PLAY button.
To Adjust
Turn the control screw to as shownin Fig.3.
Max output and same phase (both channels)
RemarkStandardPre-SetupItemStep
After adjustment secure it with REGION LOCK.
2. Adjust Deck 2 Play Level/REC BIAS
MX-G500
2
AZIMUTH1
Recording Bias Voltage
Pre-Setup Condition
SPK OUT (VTVM is connected to the scope)
Fig.4
Recording /Play head
After putting VT-703 into Deck 2
1)Press FWD PLAY button.
After putting AC-225 into Deck 2
1)Press REC PLAY button.
2)MAIN PCB JCW3, connectted to VTVM
To Adjust
Turn the control screw to as shown in Fig.3.
Turn JSR2L, JSR2R to the right and left
Max output and same phase (both channels)
7mV(
0.5mV)
RemarkStandardPre-SetupItemStep
After adjustment secure it with REGION LOCK.
AZIMUTH control screw
Audio OSC.
Fig.3
AUX IN
SET (MAIN PCB)
LINE OUT
IN
TP
JCW3
Fig.4
VTVM
IN OUT
Oscilloscope
1-23
MX-G500
Flow of functional operation until TOC read
Power ON
Play Key
RESET a CD LSI
Check Point
Confirm that the voltage at the pin17 of KB9226(IC101) is "L" "H".
LIMIT SW ON
SET Default value of TE gain, TE balance
Automatic adjusting of
focus bias
Automatic adjusting of
FE offset
Automatic adjusting of
TE offset
LASER power ON
Detection of disk
Confirm that the voltage at the pin33 of KB9226(IC101) is "H" "L" "H".
Confirm that the voltage at the pin37 of KB9226(IC101) is 3.5V.
Tracking error waveform at TOC reading
Pin 34 of KB9226 (IC101)
2.50V
Approx
0.4V
Disc states to rotate
Approx.3.7sec
Disc is rotated
Automatic adjusting of
TE balance
Automatic adjusting of
TE gain
TOC reading
Play a disc
Confirm that the signal from pin24 of KB9226(IC101) is 3.5V as a accelerated pulse during approx.1.96s.
Confirm the waveform of the Tracking error signal at the pin 34 of KB9226(IC101).
Confirm the eye-pattern at the pin2 of KB9226(IC101).
1-24
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