JVC UX-A52 User manual

1-1
UX-A52
SERVICE MANUAL
MICRO COMPONENET SYSTEM
No.21074
Feb. 2002
COPYRIGHT 2002 VICTOR COMPANY OF JAPAN, LTD.
UX-A52
UX-A52
Area Suffix
US ----------------- Singapore
UJ ---------------- U.S.Military
UP ----------------------- Korea
UW ------ Brazil,Mexico,Peru
Safety precautions
Preventing static electricity
Important for laser products
Disassembly method
Adjustment Method
Contents
Flow of functional operation
until TOC read (CD)
Maintenance of laser pickup
Replacement of laser pickup
Description of major ICs
1-2
1-3
1-4
1-5
1-24
1-28
1-29
1-29
1-30~48
STANDBY/ON
COMPACT
DIGITALAUDIO
MICRO COMPONENT SYSTEM UX-A52
PHONES
COLOR
CLOCK
/TIMER FM MODE
DISPLAY
SOUND
MODE
AHB
PRO
SET
CANCEL
CD
DIMMER
FM/AM
REV.MODE REPEAT
TAPE
STANDBY/ON
SLEEP
PLAYMODE
BEEP
VOLUME
RM-SUXA52U
AUX/MD
10
123
456
789
0
+ 10

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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.).
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.
Good earth ground
Place this
probe on
each exposed
metal part.
AC VOLTMETER
(Having 1000
ohms/volts,
or more sensitivity)
1500 10W
0.15 F AC TYPE
!
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 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.
(This regulation does not correspond to J and C version.)

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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
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.
(caption)
Anti-static wrist strap
Conductive material
(conductive sheet) or iron plate
CN601 on
mechanism
board
Shorting round
Shorting round
Flexible wire

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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
laserradiation and is equipped with safety switches
whichprevent 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.
VARNING : Osynlig laserstrålning är denna del är öppnad
och spårren är urkopplad. Betrakta ej strålen.
VARO : Avattaessa ja suojalukitus ohitettaessa olet
alttiina näkymättömälle lasersäteilylle.Älä katso
säteeseen.
ADVARSEL : Usynlig laserstråling ved åbning , når
sikkerhedsafbrydere er ude af funktion. Undgå
udsættelse for stråling.
ADVARSEL : Usynlig laserstråling ved åpning,når
sikkerhetsbryteren er avslott. unngå utsettelse
for stråling.
REPRODUCTION AND POSITION OF LABELS
WARNING LABEL
CLASS 1
LASER PRODUCT
!
CAUTION
Please use enough caution not to
see the beam directly or touch it
in case of an adjustment or operation
check.

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Remove the nine screws A on the back of the body.
Remove the two screws B on the bottom of the
body.
Unlock the speaker terminal and the antenna
terminal, then remove the rear cover backward with
releasing the hooks.
1.
2.
3.
Disassembly method
<Main body>
Removing the rear cover
(See Fig.1 and 2)
Prior to performing the following procedure, remove
the rear cover.
Remove the two screws C attaching the side panels
on the bottom of the body.
Remove each side panel backward while releasing
the eight joints a as shown in Fig.4 and 5.
1.
2.
Removing the side panels
(See Fig.3 to 5)
Fig.1
A
A
A
A
Antenna terminal
Rear cover
Speaker terminal
Fig.2
Fig.3
Fig.4 Fig.5
Side panel (R)
Side panel (L)
Side panel (L)
Rear cover
B
B
Side panel (R)
Side panel (R)
Side panel (L)
C
C
Joint a
Joint aJoint a
Joint a
(Bottom)

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Prior to performing the following procedure, remove
the rear cover and the side panels.
Remove the two screws Don each side of the body.
Release the two joints bon each side of the body
and remove the top panel in the direction of the
arrow.
Disconnect the card wires from connector CN705 on
the system control board on the left side of the body.
1.
2.
3.
Removing the top panel (See Fig.6 and 7)
Prior to performing the following procedure, remove
the rear cover, the side panels and the top panel.
Disconnect each wire from connector CN706, CN715
and CN716 on the system control board on top of the
body.
Remove the four screws Eretaining the cassette
mechanism assembly section on top of the body.
1.
2.
Removing the cassette mechanism
assembly section (See Fig.8)
Reference: If necessary, remove the
spacer marked hand the wire from the
Cassette mechanism assembly section.
REFERENCE:
Fig.7
Fig.8
Fig.6
Top panel
Top panel
D
CN705
D
System control board
CN715
System control board
CN706
E E
Joint b
Joint b
CN716
E
h (spacer)
Cassette mechanism section

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Prior to performing the following procedure, remove
the rear cover and the right side panel.
Disconnect the card wire from connector CN1 on the
tuner board on the right side of the body.
Remove the screw Gand remove the tuner board
upward while disengaging the three joints c.
1.
2.
Removing the tuner board (See Fig.10)
Prior to performing the following procedure, remove
the rear cover, the side panels and the top panel.
Disconnect the card wire from connector CN701 and
the wire from connector CN706, CN715, CN716 on
the system control board.
Remove the screw Fon the left side of the body.
Disconnect connector CN709, CN711 and CN712 on
the system control board from the body outward.
Disconnect the card wire from connector CN704 on
the underside of the system control board.
1.
2.
3.
4.
Removing the system control board
(See Fig.9)
Fig.9
Fig.10
System control board
F
CN712 CN711 CN701
CN709
CN704
CN1
G
Joints c
Tuner board
CN715
CN716
CN706

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UX-A52
Prior to performing the following procedure, remove
the rear cover, the side panels, the top panel and the
system control board.
Release the two joints don the lower right and left
sides of the front panel assembly, then remove the
front panel assembly toward the front.
1.
Removing the front panel assembly
(See Fig.11 and 12)
Prior to performing the following procedure, remove
the rear cover, the side panels, the top panel, the
system control board and the front panel assembly
section.
Disconnect the wire from connector CN804 on the
main board.
Remove the plastic rivet fixing the headphone jack
board.
1.
2.
Removing the headphone jack board
(See Fig.13 and 14)
Fig.11
Fig.12
Fig.14
Front panel assembly
Front panel assembly
Joint d
Joint d
Headphone jack board
Fig.13
Headphone jack board
Main board
CN804
Plastic rivet

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Prior to performing the following procedure, remove
the rear cover, the side panels, the top panel, the
cassette mechanism assembly section and and the
system control board.
Disconnect the wire from connector CN804 on the
main board.
Remove the five screws H attaching the cassette
mechanism bracket.
Remove the screw G attaching the grounding
terminal extending from the main board.
Disconnect connector CN805 on the main board
from the AC jack board while pulling out it. Remove
the main board in the direction of the arrow and
disconnect the wire from connector CN803 on the
reverse side of the main board.
Remove the three screws Iattaching the heat sink
on the reverse side of the main board.
1.
2.
3.
4.
5.
Removing the main board / the heat sink
(See Fig.15 to 17)
Fig.15
Fig.16
Fig.17
H
Main board
CN805
CN803
Tuner board
Heat sink I
H
G
Main board
CN804
Cassette mechanism bracket
Main board
CN804

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Prior to performing the following procedure, remove
the rear cover, the side panels, the top panel, the
cassette mechanism assembly section, the system
control board and the main board / the tuner board.
Disconnect the wire from connector CN809 on the
AC jack board.
Remove the screw Jand screw K attaching the AC
jack board.
1.
2.
Removing the AC jack board
(See Fig.18 and 19)
Prior to performing the following procedure, remove
the rear cover, the side panels, the top panel, the
cassette mechanism assembly section, the system
control board and the main board.
Disconnect the wire from connector CN809 on the
AC jack board.
Cut off the band setting the wire on the CD
mechanism cover.
Remove the four screws L attaching the power
transformer assembly.
1.
2.
3.
Removing the power transformer
assembly (See Fig.20)
Fig.18
AC jack board
CN809
K
J
Fig.19
AC jack board
CN809
Power transformer assembly
Fig.20
L
AC jack board
CN809
Power transformer
assembly
Band
L

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Prior to performing the following procedure, remove
the rear cover, the side panels, the top panel, the
cassette mechanism assembly section, the system
control board, the front panel assembly section, the
main board / the tuner board and the AC jack board.
Cut off the band setting the wire on the CD
mechanism cover.
Release the wire extending from the headphone jack
board from the spacer and the three notches of the
CD mechanism cover on the left side of the body.
Remove the four screws Mon the left and right side
of the CD mechanism cover. Then remove the CD
mechanism cover upward.
Remove the three screws N attaching the CD
mechanism assembly.
1.
2.
3.
4.
Removing the CD mechanism assembly
(See Fig.21 to 23)
Fig.23
CD mechanism assembly
Fig.22
CD mechanism cover
Band
CD mechanism assembly
M
N
N
Fig.21
CD mechanism cover
Band
CD mechanism assembly
Notches
Notch
M
Spacer

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Prior to performing the following procedure, remove
the relay board.
Remove the four screws P attaching the drive motor
assembly.
1.
<Front panel assembly section>
Removing the drive motor assembly
(See Fig.25)
Disconnect the wire from connector CN906, CN907
and the card wire from CN908 on the relay board
respectively.
Remove the two screws O.
Prior to performing the following procedure, remove
the rear cover, the side panels, the top panel, the
system control board and the front panel assembly
section.
1.
2.
Removing the relay board (See Fig. 24)
Remove the two screws Qattaching the plate.
Remove the belt from the two pulleys.
Remove the two screws Rattaching the drive motor.
1.
2.
3.
Removing the belt and the drive motor
(See Fig.26)
The belt and the drive motor can be
removed respectively without removing the
drive motor assembly from the front panel
section.
REFERENCE:
When removing the drive motor only,
remove the belt from the drive motor
pulleys in advance.
REFERENCE:
Fig.24
Fig.25
Fig.26
O
Relay board
CN906
O
CN907
CN908
P
P
Door switch board
Drive motor assembly
Drive motor
Belt
Plate
Q
R

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Prior to performing the following procedure, remove
the relay board.
Loosen the screw S attaching the door switch.
Remove the door switch board while releasing it from
the joint e.
1.
2.
Prior to performing the following procedure, remove
the relay board.
Loosen the two screws T attaching the lock lever.
Push the part fof the lock lever in the direction of
the arrow as shown in Fig.30-1 / 30-2 and disengage
the LCD section from the front panel assembly.
1.
2.
Removing the door switch board
(See Fig.27 and 28)
Removing the LCD section
(See Fig.29 to 31)
When reattaching the door switch board,
fit it to the joint e and check the
operating state of the switch before
tightening the screw S.
CAUTION:
Because the LCD may come off, hold it
when loosening the screws T.
CAUTION:
Fig.27
Fig.28
Fig.29
Fig.30-1 Fig.30-2 Fig.31
S
Joint e
Joint e
Joint f
Door switch board
Door switch board
S
T
T
Lock lever fLock lever f
Lock lever Lock lever
LCD section
Switch section
Front panel assembly
Front panel assembly
Drive motor assembly
Joint f

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Removing the LCD board assembly
(See Fig.32 to 36)
Prior to performing the following procedure, remove
the relay board and the LCD section.
Remove the four screws Uattaching the case cover.
Remove the four screws Vattaching the LCD panel
on the back of the LCD section.
Remove the LCD cover.
Release the three joints gand remove the LCD
board assembly in the direction of the arrow.
1.
2.
3.
4.
Fig.32
Fig.33
Fig.34
Fig.35 Fig.36
UCase cover
U
V
V
LCD section
LCD panel
LCD cover
LCD board assembly
Joint g
U
U
Joint g
Joint g

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Remove the seven screws W attaching the
operation switch board on the reverse side of the top
panel.
Prior to performing the following procedure, remove
the rear cover, the side panels and the top panel.
1.
<Top panel section>
Removing the operation switch board
(See Fig.37)
Fig.37
Cassette amplifier board
W
W
W
Operation switch board

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Note: When drawing out the tray, shift down the
TRAMECHA assembly to the position where
the tray does not contact the T-T assembly
of the TRAMECHA assembly.
Note: When reinstalling the tray:
Turn the idle gear so that the part b of the
tray gear is positioned in the part c shown in
Fig. 4. (Eject position)
Engage the right and left hooks d and e of
the tray with the right and left grooves of the
TRAMECHA assembly respectively for
retaining the tray.
<CD Mechanism Assembly>
Removing the CL. Base Assembly and Tray
(Refer to Figs. 1 to 5.)
1. Remove the two screws A fastening the CL. base
assembly from the top of the CD mechanism
assembly.
2. Move the CL. base assembly diagonally upwards
as indicated by the arrow to release it from the two
hooks a.
3. Turn the idle gear in the arrow-marked direction
from the upper side of the CD mechanism
assembly. Accordingly, the TRAMECHA assembly
moves downwards.
4. Draw out the tray frontwards for removing it.
Fig. 1
Fig. 2
Fig. 3
Fig. 4Fig. 5
A
CL. base assembly
A
Hook a
Hook a
Idle gear
TRAMECHA
assembly
Tray
TRAMECHA assembly
Idle gear
Tray
Tray gear
Part c
Idle gear
Tray gear
Hook d
Hook d
Tray Part b

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Reference: The TRAMECHA assembly can be
removed without removal of the
mechanism board.
Note: When reinstalling the TRAMECHA assembly:
Check to see if the spring is properly
engaged with groove of the CH. base
assembly in the part g of the TRAMECHA
assembly.
After making sure that the three insulators of
the TRAMECHA assembly are properly set
on the bosses of the L. base assembly's
guide, fasten them with the screws.
Removing the TRAMECHA Assembly
(Refer to Figs. 6 to 9.)
Remove the CL. base assembly and tray.
1. If the TRAMECHA assembly is lowered and it is
located out of the PLAY position, turn the idle gear
in the arrow-marked direction so that the hole in the
part f of the tray gear meets the hole on the CL.
base assembly. (Set the TRAMECHA assembly at
the PLAY position.)
2. Remove the three screws B fastening the
TRAMECHA assembly and then remove the
TRAMECHA assembly upwards from the front side.
3. At the same time, remove the spring from the groove of
the CH. base assembly in the part g of the TRAMECHA
assembly.
Fig. 6
Fig. 7
Fig. 8
Fig. 9
BB
Idle gear
TRAMECHA
assembly
B
Tray gear
Part g
Tray gear
Part f
L. base assembly
Spring
Part g
Spring
Groove of CH. base assembly

1-18
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Reference:The mechanism board can be removed
without removal of the TRAMECHA
assembly.
Note: Before disconnecting the flexible wire coming
from the pickup from the connector, be sure to
solder its shorting round.
If the flexible wire is connected without
soldering, it may cause breakdown of the
pickup.
Removing the Mechanism Board
(Refer to Fig 10.)
1. Solder the shorting round of the flexible wire
connected with the mechanism board from the back
of the mechanism assembly.
2. Disconnect the flexible wire from the connector
CN601 on the mechanism board.
3. Remove the three screws C fastening the
mechanism board.
4. Unsolder the two points of the part h and one point
of the part i of the mechanism board. Then, remove
the mechanism board upwards.
Note: When reinstalling the mechanism board,
connect the flexible wire coming from the
pickup to the connector first and then remove
the solder from the shorting round of the
flexible cable.
Fig. 10
C
CC
CN601 on
mechanism
board
Flexible wire
Shorting round
Soldered
part h
Soldered part i

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Reference: The pickup can be removed without
removal of the mechanism board.
Note: Before disconnecting the flexible wire coming
from the pickup from the connector, be sure to
solder its shorting round.
If the flexible wire is connected without
soldering, it may cause breakdown of the
pickup.
Removing the Pickup
(Refer to Figs. 11 to 14.)
Remove the CL. base assembly and tray.
Remove the TRAMECHA assembly.
1. Solder the shorting round of the flexible wire
connected with the mechanism board from the back
of the TRAMECHA assembly.
2. Disconnect the flexible wire from the connector
CN601 on the mechanism board.
3. Turn the idle gear in the arrow-marked direction from
the top of the TRAMECHA assembly so that the
pickup assembly is shifted to the reverse side of the
T-T assembly.
Move the pickup assembly until the part j of the rack
plate in the lower part of the pickup assembly comes
out of the CH. base assembly.
4. Remove the two screws D retaining the shaft of the
pickup assembly. Next, disengage the hook k from
the CH. base assembly and then remove the pickup
assembly together with the shaft.
5. Pull the shaft out of the pickup.
6. Remove the two screws E fastening the rack plate
from the pickup.
7. Remove the screw F retaining the P.S. spring from
the pickup.
Fig. 11
Fig. 12
Fig. 13
Fig. 14
D
D
Pickup assembly
Flexible wire
Shorting round
CN601 on
mechanism
board
Pickup assembly
T-T assembly
CH. base
assembly
Part j of
rack plate
Idle gear
Part k
CH. base
assembly
Shaft
E
Pickup
P.S. spring
F
Part j
Rack plate

1-20
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Reference: Refer to the explanation of "Removing
the Pickup" on the preceding page.
Note: When reinstalling the pickup assembly,
remove the solder from the shorting round
after connecting the flexible wire coming from
the pick to the connector CN601.
Reinstalling the Pickup Assembly
(Refer to Figs. 15 and 16.)
1. Fit the P.S. spring and rack plate to the pickup.
2. Insert the shaft into the pickup.
3. Engage the hook k of the pickup assembly with the
CH. base assembly first, and set the part j of the
rack plate in the opening I next. Then, reinstall the
pickup assembly while shifting it to the T-T side
(inward) so that the part m of the rack plate is
positioned as shown in Fig. 16.
4. Move the pickup assembly to the center position
and fasten the shaft with the two screws D. (Make
sure that the part n of the rack plate is correctly
engaged with the middle gear.)
5. After passing the flexible wire coming from the
pickup through the opening of the CH. base
assembly, connect it to the connector CN601.
Removing the Feed Motor Assembly
(Refer to Fig. 17.)
Remove the CL. base assembly and tray.
Remove the mechanism board.
Remove the two screws E fastening the feed motor
assembly from the top of the mechanism assembly.
Fig. 15
Fig. 16
Fig. 17
Part k
Part j
Pickup
assembly
Part I CH. base
assembly
Middle gear
Part n
Rack plate
Part m
Feed motor assembly
E