JVC UX-F70MD User manual

1-1
UX-F70MD/UX-F72MD
SERVICE MANUAL
MICRO COMPONENT MD SYSTEM
No.21028
Sep. 2001
COPYRIGHT 2001 VICTOR COMPANY OF JAPAN, LTD.
UX-F70MD
UX-F72MD
UX-F70MD/UX-F72MD
Contents
Safety precautions
Preventing static electricity
Important for laser products
Disassembly method
Adjustment Method 1
(CD/MD section)
Adjustment Method 2
(Cassette mechanism section)
Flow of functional operation
until TOC read (CD)
Flow of functional operation
until TOC read (MD)
Maintenance of laser pickup
Replacement of laser pickup
Maintenance of MD pickup
Procedures of changing
the MD pickup
Description of major ICs
1-2
1-3
1-5
1-6
1-35
1-38
1-40
1-41
1-42
1-42
1-43
1-43
1-44~71
This service manual is printed on 100% recycled paper.
Area Suffix
UB
UF
Hong Kong
China
COLOR
MDGROUP
MDTITLE
IMPUT/EDIT
CLOCK
/TIMER FMMODE
DISPLAY
/CHARA
MDTITLE
SEARCH
SOUND
MODE AHB PRO
SET
CANCEL
CD
DIMMER
1 2 3
ENTER
FM/AM
/AUX
REV.MODE
REPEAT
TAPE
STANDBY/ON
SLEEP
PLAYMODE
BEEP
VOLUME
MD
4 5 6
7 8 9
10 0
+ 10
RM-SUXF70MDU
MARK
STANDBY/ON
COMPACT
DIGITALAUDIO
MICRO COMPONENT MD SYSTEM UX-F70MD
PHONES
COLOR
MDGROUP
MDTITLE
IMPUT/EDIT
CLOCK
/TIMER FMMODE
DISPLAY
/CHARA
MDTITLE
SEARCH
SOUND
MODE
AHB
PRO
SET
CANCEL
CD
DIMMER
1 2 3
ENTER
FM/AM
/AUX
REV.MODE
REPEAT
TAPE
STANDBY/ON
SLEEP
PLAYMODE
BEEP
VOLUME
MD
4 5 6
7 8 9
10 0 + 10
RM-SUXF70MDU
MARK
STANDBY/ON
COMPACT
DIGITALAUDIO
MICRO COMPONENT MD SYSTEM UX-F72MD
PHONES
CA-UXF72MDCA-UXF70MDSP-UXF70MD SP-UXF70MD SP-UXF72MD SP-UXF72MD

1-2
UX-F70MD/UX-F72MD
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 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 eachexposed 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.).
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.
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
!
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.

1-3
UX-F70MD/UX-F72MD
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.
1.1. Grounding to prevent damage by static electricity
Static electricity in the work area can destroy the optical pickup (laser diode) in devices such as DVD players.
Be careful to use proper grounding in the area where repairs are being performed.
1.1.1. Ground the workbench
1. 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.
1.1.2. Ground yourself
1. Use an anti-static wrist strap to release any static electricity built up in your body.
1.1.3. 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.
1.2. Handling the traverse unit (optical pickup)
1. Do not subject the traverse unit (optical pickup) to strong shocks, as it is a sensitive, complex unit.
2. Cut off the shorted part of the flexible cable using nippers, etc. after replacing the optical pickup. For specific
details, refer to the replacement procedure in the text. Remove the anti-static pin when replacing the traverse
unit. Be careful not to take too long a time when attaching it to the connector.
3. Handle the flexible cable carefully as it may break when subjected to strong force.
4. It is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not turn it
Conductive material
(conductive sheet) or iron plate
(caption)
Anti-static wrist strap

1-4
UX-F70MD/UX-F72MD
1.3. Cautions on removing the CD traverse unit
* For removing the CD traverse unit in detail, refer to the "Adjustment Method" section of this manual.
1. Before disconnecting the flexible wire from the connector CN601 on the CD SERVO board, solder the part shown in
the figure below.
(Note:If the flexible wire is disconnected from the CN601 without presoldering, it may cause breakdown of the CD
pickup assembly.)
2. When reassembling the CD traverse unit, be sure to remove the solder from the soldered part after reconnecting the
flexible wire to the CN601.
CD SERVO board
CD SERVO board
Soldering part
CN601
CN601
CN321
CN451
Pickup Soldering part b
MAIN board
CD SERVO board

1-5
UX-F70MD/UX-F72MD

1-6
UX-F70MD/UX-F72MD
Remove the seven 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
Fig.2
Fig.3
Fig.4
Fig.5
A
A
A
A
Antenna terminal
Rear cover
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 a
Joint a
Joint a
Speaker terminal
(Bottom)

1-7
UX-F70MD/UX-F72MD
Prior to performing the following procedure, remove
the rear cover and the side panels.
Remove the two screw Don each side of the body.
Release the joint bon each side of the body and
remove the cassette mechanism assembly section in
the direction of the arrow.
Disconnect the card wires from connector CN705,
CN743 and CN744 on the system control board on
the left side of the body.
1.
2.
3.
Removing the cassette mechanism
assembly section (See Fig.6 and 7)
Prior to performing the following procedure, remove
the rear cover, the side panels, the cassette
mechanism assembly section and the fan assembly.
Disconnect the card wire from connector CN721 on
the system control board.
Disconnect the card wire from connector CN522 on
the underside of the MD mechanism assembly
section.
Remove the four screws Fand the MD mechanism
assembly section upward.
1.
2.
3.
Removing the MD mechanism assembly
section (See Fig.8)
Prior to performing the following procedure, remove
the rear panel and the right side panel.
Disconnect the wire from connector CN907 on the
main board on the right side of the body.
Remove the two screws E attaching the fan
assembly.
1.
2.
Removing the fan assembly (See Fig.6)
Fig.7
Fig.8
Fig.6
Cassette mechanism assembly
Cassette mechanism assembly
E
E
D
Fan assembly
Main board
CN907
CN744
CN743
CN705
D
System control board
CN522
MD mechanism assembly
F
F
F
F
System
control board
CN721
Front panel
Joint b
Joint b

1-8
UX-F70MD/UX-F72MD
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 Hand remove the tuner board
upward while disengaging the three joint 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 cassette
mechanism assembly section.
Remove the screw Gon the left side of the body.
Disconnect the card wire from connector CN701 and
CN721on the system control board.
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
G
CN712 CN711
CN701 CN721
CN709
CN704
CN1 H
Joint c
Tuner board

1-9
UX-F70MD/UX-F72MD
Prior to performing the following procedure, remove
the rear cover, the side panels, the cassette
mechanism assembly section 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 rear cover, the side
panels, the cassette mechanism assembly section,
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.13
Fig.14
Front panel assembly
Front panel assembly
Joint d
Joint d
Headphone jack board
Headphone jack board
Main board
CN804
Plastic rivet

1-10
UX-F70MD/UX-F72MD
Prior to performing the following procedure, remove
the rear cover, the side panels, the cassette
mechanism assembly section, the system control
board, the MD mechanism assembly section and the
main board / the tuner board.
Disconnect the wire from connector CN809 on the
AC jack board.
Remove the screw Kand screw L 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 cassette
mechanism assembly section, the system control
board and the MD mechanism assembly section.
Remove the screw I attaching the main board.
Remove the screw H attaching the grounding
terminal extending from the main board.
Disconnect the wire from connector CN804 on 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 Jattaching 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
Fig.18
Fig.19
CN804
CN803
I
H
Main board
CN805
Main board
Main board
CN803
CN805
CN804
Heat sink
Heat sink J
CN809
AC jack board
AC jack board
AC jack board
CN809
L
K
Power transformer assembly

1-11
UX-F70MD/UX-F72MD
Prior to performing the following procedure, remove
the rear cover, the side panels, the cassette
mechanism assembly section, the system control
board, the MD mechanism assembly section 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 M attaching the power
transformer assembly.
1.
2.
3.
Removing the power transformer
assembly (See Fig.20)
Prior to performing the following procedure, remove
the rear cover, the side panels, the cassette
mechanism assembly section, the system control
board, the front panel assembly section, the MD
mechanism assembly section, the main board / the
tuner board and the AC jack board.
Cut off the band setting the wire on CD mechanism
cover.
Release the wire extending from the headphone jack
board from the three notches of the CD mechanism
cover on the left side of the body.
Remove the four screws Non the left and right side
of the CD mechanism cover. Then remove the CD
mechanism cover upward.
Remove the three screws O attaching the CD
mechanism assembly.
1.
2.
3.
4.
Removing the CD mechanism assembly
(See Fig.21 to 23)
Fig.20
Fig.21
Fig.22
Fig.23
M
AC jack board
CN809
Power transformer
assembly
CD mechanism cover
CD mechanism cover
CD mechanism cover
Band
Band
Band
M
CD mechanism assembly
CD mechanism assembly
CD mechanism assembly
Headphone
jack board
Notches
Notch
N
N
O
O

1-12
UX-F70MD/UX-F72MD
<MD mechanism assembly section>
Removing the MD mechanism assembly
(See Fig.24 to 26)
Remove the four screws Pattaching the brackets
(1) and (2) on the left and right side of the MD
mechanism assembly.
Disconnect the card wire from connector CN521 on
the MD mechanism board.
Remove the MD mechanism bottom cover
downward.
Prior to performing the following procedure, remove
the rear cover, the side panels, the cassette
mechanism assembly section, the fan assembly and
the MD mechanism assembly section.
1.
2.
3.
Fig.24
Fig.25
Fig.26
P
MD mechanism assembly
MD mechanism assembly
MD mechanism assembly
brackets (1)
brackets (2)
P
MD mechanism bottom cover
CN521

1-13
UX-F70MD/UX-F72MD
Prior to performing the following procedure, remove
the relay board.
Remove the four screws R attaching the drive motor
assembly.
1.
<Front panel assembly section>
Removing the drive motor assembly
(See Fig.28)
Disconnect the wire from connector CN906, CN907
and the card wire from CN908 on the relay board
respectively.
Remove the two screws Q.
Prior to performing the following procedure, remove
the rear cover, the side panels, the cassette
mechanism assembly section, the system control
board and the front panel assembly section.
1.
2.
Removing the relay board (See Fig. 27)
Remove the two screws Sattaching the plate.
Remove the belt from the two pulleys.
Remove the two screws Tattaching the drive motor.
1.
2.
3.
Removing the belt and the drive motor
(See Fig.29)
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.27
Fig.28
Fig.29
Q
Relay board
CN906
Q
CN907
CN908
R
R
Door switch board
Drive motor assembly
Drive motor
assembly
Drive motor
Belt
Plate
S
T

1-14
UX-F70MD/UX-F72MD
Prior to performing the following procedure, remove
the relay board.
Loosen the screw U 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 V attaching the lock lever.
Push the part fof the lock lever in the direction of
the arrow as shown in Fig.33-1 / 33-2 and disengage
the LCD section from the front panel assembly.
1.
2.
Removing the door switch board
(See Fig.30 and 31)
Removing the LCD section
(See Fig.32 to 34)
When reattaching the door switch board,
fit it to the joint e and check the
operating state of the switch before
tightening the screw U.
CAUTION:
Because the LCD may come off, hold it
when loosening the screws V.
CAUTION:
Fig.30
Fig.31
Fig.32
Fig.33-1 Fig.33-2
Fig.34
U
Joint e
Joint e
Joint f
Door switch board
Door switch board
U
V
V
Lock lever fLock lever f
Lock lever Lock lever
LCD section
Switch section
Front panel assembly
Front panel assembly
Drive motor assembly

1-15
UX-F70MD/UX-F72MD
Removing the LCD board assembly
(See Fig.35 to 39)
Prior to performing the following procedure, remove
the relay board and the LCD section.
Remove the four screws Wattaching the case
cover.
Remove the four screws Xattaching the LCD panel
on the back of the LCD section.
Remove the LCD cover.
Release the joint gand remove the LCD board
assembly in the direction of the arrow.
1.
2.
3.
4.
Fig.35
Fig.36
Fig.37
Fig.38Fig.39
W
Case cover
W
X
X
LCD section
LCD panel
LCD cover
LCD board assembly
Joint g
W
W

1-16
UX-F70MD/UX-F72MD
Remove the seven screws Y attaching the operation
switch board on the reverse side of the cassette
mechanism assembly.
Prior to performing the following procedure, remove
the rear cover, the side panels and the cassette
mechanism assembly section.
1.
<Cassette mechanism assembly section>
Removing the operation switch board
(See Fig.40)
Remove the four screws Zon the reverse side of the
cassette mechanism assembly.
1.
Removing the cassette mechanism
assembly (See Fig.41)
Fig.40
Fig.41
Cassette amplifier board
Cassette amplifier board
Y
Y
Y
Z
Z
Operation switch board
Cassette mechanism assembly

1-17
UX-F70MD/UX-F72MD
Turn over the body and disconnect the card wire
from connector CN408 and the flexible wire from
CN407 on the main board.
Remove the two screws A attaching the main board.
Slide the main board in the direction of the arrow to
release the two joints a with the single flame.
Solder part b on the pickup in the body. Disconnect
the flexible harness from connector CN321 and
CN451 on the underside of the main board. Then
remove the main board.
1.
2.
3.
Disassembly method
Removing the main board
(See Fig.1 and 2)
Remove the four screws B on both sides of the
body.
Move the mechanism cover toward the front to
disengage the front hook of the mechanism cover
from the internal loading assembly (Joint c). Then
remove the mechanism cover upward.
1.
2.
Removing the mechanism cover
(See Fig.3)
<Main body>
Fig.1
Fig.2
Fig.3
AA
Main board
(Bottom)
CN408
CN321
CN451
Pickup
Joint c
Fook
Joint c
Mechanism cover
Solder part b
CN407
Joint b Joint b
Main board
B
B

1-18
UX-F70MD/UX-F72MD
Move the head lifter on top of the body in the
direction of the arrow and turn around.
Detach the spring from the hook of the body.
Remove the head lifter with the spring.
If necessary, remove the spring from the head lifter.
1.
2.
3.
Removing the head lifter (See Fig.4 to 6)
Remove the screw C on the upper side of the body.
Remove the head assembly while pulling the flexible
harness from the body.
1.
Removing the head assembly (See Fig.7)
Fig.4
Fig.5
Fig.6
Fig.7
C
Head lifter
Spring
Spring
Head lifter
Head assembly
Head lifter

1-19
UX-F70MD/UX-F72MD
Prior to performing the following procedure, remove
the main board, the mechanism cover, the head lifter
and the head assembly.
Remove the three screws D on the upper side of the
body.
Move the loading assembly forward to disengage it
from the traverse mechanism assembly (Joint d).
Then remove it upward.
Remove the traverse mechanism assembly from the
single flame.
1.
2.
3.
Removing the Loading assembly
(See Fig.8 and 9)
The loading assembly, the traverse mechanism
assembly and the single flame will be
removable after removing the loading assembly
from the body.
Ref:
Fig.8
Fig.9
D
Loading assembly
Joint d
D
D
Loading assembly
Traverse mechanism
assembly
Single flame

1-20
UX-F70MD/UX-F72MD
Remove the two screws E on the upper side of the
loading assembly.
Remove the slide base (L) outward. (Release it from
the joint bosses E.)
Remove the slide base (R) outward.
1.
2.
3.
Removing the slide base (L) / (R)
(See Fig.10)
Detach the loading mechanism assembly upward to
release the four pins on both sides from the loading
motor, paying attention to the part e of the loading
mechanism base.
1.
Removing the loading mechanism
assembly (See Fig.11)
Disconnect the harnesses from the wire holder and
from connector CN612 on the cam switch board.
Remove the screw F attaching the loading motor
and release the joint f.
Remove the belt from the loading motor assembly.
Remove the two screws G attaching the loading
motor.
1.
2.
3.
4.
Removing the loading motor
(See Fig.12 and 13)
Loading mechanism assembly
Remove the slit washer attaching the cam gear and
pull out the cam gear.
Disconnect the harness from the wire holder and
from connector CN612 on the cam switch board.
Remove the two screws H and the clamp. Remove
the cam switch board.
1.
2.
3.
Removing the cam gear and the cam
switch board (See Fig.12)
<Loading assembly>
Fig.10
Fig.11
Fig.12
Fig.13
E'
E'
E
E
Loading motor assembly
Loading mechanism
assembly
Loading mechanism base
Slide base (R)
Slide base (L)
F
H
H
Joint f
Part e
CN612
Slit washer
Cam gear
Loading motor
Cam switch board
Wire holder
Belt
G