JVC MXJ-170-V Service manual

SERVICE MANUAL

COMPACT COMPONENT SYSTEM

MX-J170V

MX-J170V

SLEEP

L

NTSC/PA

KEY CONTROL

T

REPEA

PROGRAM/SET

CD

DECK A/B TUNING MODEFM MODE

0

T

CD

APE

SELECT

DISC SKIP

PREV

RM–SMXJ170V REMOTE CONTROL

TIMER

ON/OFF

SLOWSINGLE STEP

ECHO

BASS

VOLUME

VOLUME

FADE MUTING

+

7

–

STANDBY

PLAY & EXCHANGER

NTSC/PAL COMPATIBILITY

CLOCK

ACTIVE

COUNTER

SOUND

/TIMER

BASS EX.

RESET

MODE

DEMO

MPX

KEY

/V.REPLACE

CONTROL

/V.MASKING

ECHO

PBC

(MENU)

+

VCD

NUMBER

V. MASKING

–

SOUND MODE

AUX

FM/AM

NEXT

PHONES

MIC LEVEL

MIN

MAX

MIC

AUX FM/AM

PROGRAM/SET

NTSC/PAL

PLAY REC/PLAY

FULL-LOGIC CONTROL

PREV NEXT

CD TAPE

-

VCD NUMBER

VCD NUMBER +

PRESET

CD SYNCHRO RECORDING

CD

2

CD

1

SELECT

OPEN / CLOSE

DISC CHANGE

CD

3

COMPACT

DIGITAL VIDEO

VIDEO CD

VOLUME

+

–

CD REC
START

TAPE A/B

REC/PAUSE

A B

DUBBING

EJECTEJECT

Area Suffix

PlayBack

Control

VIDEO CD

US
U

Singapore

Other Areas

Contents

Safety precautions
Important for laser products
Preventing static electricity
Disassembly method
Adjustment method

COPYRIGHT 2000 VICTOR COMPANY OF JAPAN, LTD.

1-2
1-3
1-4
1-5
1-21

Flow of functional operation
until TOC read
Maintenance of laser pickup
Replacement of laser pickup
Description of major ICs

1-25
1-26
1-26
1-27

No.20859

Nov. 2000

MX-J170V

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 proper ty
damage resulting therefrom.

3. Many electrical and mechanical par ts 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 or iginal lead
routing and dress should be observed, and it should be confirmed that they have been returned
to normal, after re-assembling.

5. Leakage current 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, par ticularly 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.).

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.

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.

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.

1-2

CAUTION

!

Important for laser products

MX-J170V

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.

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.

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.

CAUTION

!

Please use enough caution not to
see the beam directly or touch it
in case of an adjustment or operation
check.

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

DANGER : Invisibie laser radiation
when open and interlock or
defeated.
AVOID DIRECT EXPOSURE TO
BEAM (e)

VARO : Avattaessa ja suojalukitus
ohitettaessa olet alttiina
näkymättömälle lasersäteilylle.Älä
katso säteeseen. (d)

CLASS 1
LASER PRODUCT

VARNING : Osynlig laserstrålning är
denna del är öppnad och spårren är
urkopplad. Betrakta ej strålen. (s)

ADVARSEL :Usynlig laserstråling
ved åbning , når
sikkerhedsafbrydere er ude af
funktion. Undgå udsættelse for
stråling. (f)

1-3

MX-J170V

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

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.

CD changer unit

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.

1-4

Card wire

Pickup unit
connector

Soldering

CD mechanism

Fig.1

Card wire

Pickup unit
connector

Fig.2

MX-J170V

Disassembly method

<Main body>

Removing the top cover and the side
covers (See Fig.1 to 3)

1.

Remove the five screws A on the back of the body
and the both sides of the body.

2.

Remove the top cover upward from behind.

3.

Remove the eight screws B attaching the side
covers on the back of the body and the both side of
the body.

4.

Slide the right and left covers backward and unhook
the two hooks a in the lower part of the side covers
as shown in Fig.2-2.

Hook

A

B

Side cover (L)

A

Fig.1

Top cover

Top cover

A

B

Side cover (R)

A

Hook

Side cover (R)

B

B

A

Hooks a

Fig.2Fig.2-2

Top cover

B

B

B

Hooks a

Fig.3

Side cover (L)

B

1-5

MX-J170V

Removing the CD Tray fitting

(See Fig. 4 to 6)

Prior to performing the following procedure, remove
the top cover and the side covers.

ATTENTION:

1.

Press the POWER button. Press the OPEN/CLOSE
button to eject the CD tray.

2.

Move the CD tray fitting upward and release the joint
b.

3.

Press the OPEN/CLOSE button to insert the CD tray.

Be sure to remove the CD tray fitting
before removing the CD changer unit.

CD tray

OPEN/CLOSE button

POWER button

Fig.4

Joint b

CD tray fitting

Joint b

CD tray

Fig.5

Fig.6

1-6

Prior to performing the following procedure, remove
the top cover and the side covers.

Disconnect the harness from connector PCON1 of
the VCD board.

Remove the four screws W attaching the sealed and
VCD board.

Turn the black loading pulley gear marked c from the
back of the CD changer unit as shown in Fig.8 and
draw the CD tray toward the front.

Move the CD tray fitting upward and release the joint
b.

Push and insert the CD tray manually.

1.

2.

3.

4.

5.

Removing the CD Tray fitting & the VCD
board (See Fig.7 to 10)

Be sure to remove the CD tray fitting
before removing the CD changer unit.

ATTENTION:

- How to eject the CD tray without turning on power -

Fig.9

Fig.10

Joint b

Joint b

CD tray fitting

CD tray

Fig.7

Fig.8

W

VCD board

Sealed

PCON1

Marked c
Loading pulley gear

MX-J170V

1-7

MX-J170V

Removing the CD changer unit

(See Fig.11 to 13)

Prior to performing the following procedure, remove
the top cover, the side covers and the CD Tray
fitting.

1.

Disconnect the card wire from connector SCW1 of
the CD servo board on the back of the CD changer
unit.

2.

Disconnect the harness from connector FW2 on the
inner side of the main board in the body.

3.

Disconnect the harness from connector VCW2 on
the VDC power board .

4.

Remove the two screws C attaching the CD changer
unit on the back of the body.

5.

Draw the CD changer unit upward from behind while
pulling the rear panel outward.

CD servo board

SCW1

Main board

CD changer unit

FW2

Fig.11

VCD power board

VCW2

C

Rear panel

Front panel assembly

CD changer unit

Fig.12

Rear panel

VCD power board

Fig.13

1-8

MX-J170V

Removing the front panel assembly

(See Fig.14 to 16)

Prior to performing the following procedure, remove
the top cover, the side covers, the CD Tray fitting
and the CD changer unit.

There is no need to remove the rear panel.

1.

Disconnect the harness from head wire connector
ECW1,DW1 and DW2 on the inner side of the main
board in the body.

2.

Disconnect the harness from connector HCW1 of the
headphone board on the right side of the body.

3.

Remove the three screws D attaching the front panel
assembly on both sides of the body.
Remove the screw E attaching the earth terminal
extending from the front compartment.

4.

Remove the screw F attaching the front panel
assembly on the bottom of the body.

5.

Release the two joints d on both sides and two joints
e on the bottom of the body using a screwdriver. At
the same time, disconnect the front compartment
from connector CCW1 and CCW2 of the main board.

Front panel assembly

Joint d

D

CCW1

CCW2

E

Fig.14

earth wire

Front panel assembly

D

MIC
/Headphone board
HCW1

Main board

DW1

DW2

ECW1

Joint e

D

Main board

Fig.15

F

Fig.16

Joint d

Joint e

1-9

MX-J170V

Removing the rear panel (See Fig.17)

Prior to performing the following procedure, remove
the top cover, the side covers, the CD Tray fitting
and the CD changer unit.

There is no need to remove the front panel
assembly.

1.

Remove the ten screws G attaching the main board,
the tuner board and the heat sink to the rear panel
on the back of the body.

2.

Remove the three screws H attaching the VCD
power board to the rear panel on the back of the
body.

3.

Remove the four screws I attaching the rear panel on
the back of the body.

Rear panel

H

G

G

G

G

I

Fig.17

Front panel assembly

Removing the main board

(See Fig.18 and 19)

Prior to performing the following procedure, remove
the rear panel.

1.

Disconnect the harness from connector HCW1 of the
MIC/headphone board on the right side of the body.
Release the harness from the clamp in the body.

2.

Disconnect the harness from head wire connector
ECW1,DW1 and DW2 extending to the main board
in the body.

3.

Disconnect the harness from connector RCW1 of the
power transformer.

4.

Remove the screws D attaching the front panel
assembly on both sides of the body.

5.

Remove the screw J attaching the earth terminal to
the base chassis.

6.

Disconnect connector CCW1 and CCW2 connected
to the main board.

CCW2

Clamp

CCW1

D

MIC/
headphone board
HCW1

Main board

Fig.18

DW1

DW2

ECW1

Main board

Tuner board

Heat sink

VCD board

J

RCW1

Fig.19

Power transformer

1-10

MX-J170V

Prior to performing the following procedure, remove
the main board.

Disconnect the harness from connector MJW1 of the
main board.

Remove the three screws K attaching the heat sink
cover plate and cooling fan.

Remove the two screws L attaching the power IC to
the heat sink and the three screws M attaching the
heat sink to the main board.

1.

2.

3.

Removing the heat sink & cooling fan

(See Fig.20 and 21)

The tuner board can be removed even if the main
board is attached.

Release the joint tab f of the tuner board holder and
the main board, and disconnect connector FW1
connected to the main board. Remove the tuner
board assembly (Refer to Fig.21).

Remove the screw N attaching the tuner board
holder. Release the two tabs g outward and remove
the tuner board from the tuner board holder.

1.

2.

Removing the tuner Board

(See Fig.21 to 23)

Fig.23

Fig.22

Fig.21

Fig.20

K

L

Main board

Joint tab f

Tuner board

M

Heat sink

Tuner board

Main board

TWA1

Tuner board

Tab g

Tab g

Tuner board holder

Heat sink cover plate

Heat sink cover plate

N

Cooling Fan

TWA1

MJW1

1-11

MX-J170V

Removing the heat sink & VCD Power
board (See Fig.24 and 25)

Prior to performing the following procedure, remove
the top cover and the side covers.

1.

Remove the two screws O attaching the heat sink
plate.

2.

Remove the two screws P attaching the power IC to
the heat sink and the two screws Q attaching the
heat sink to the VCD Power board.

VCD Power board

Heat sink

O

Q

Heat sink

P

P

O

Fig.24

VCD Power board

Q

Removing the power transformer

(See Fig.26)

Prior to performing the following procedure, remove
the VCD Power board.

1.

Disconnect the power cord from connector RCW2 of
the power transformer.

2.

Disconnect the harness from connector RCW1 of the
power transformer.

3.

Remove the four screws R attaching the power
transformer.

ATTENTION:

Prior to disconnecting the power cord
from the body, remove the rear panel.

RCW1

Fig.25

R

Power transformer

Fig.26

RCW2

Power cord

R

1-12

MX-J170V

Prior to performing the following procedure, remove
the power / CD switch board.

Pull out the volume knob toward the front.
Disconnect the card wire from the mechanism board

of the cassette mechanism assembly.
Remove the nine screws T attaching the front board.

1.

2.

3.

Removing the front board

(See Fig.27 and 28)

Remove the three screws S attaching the power/CD
switch board and release the three tabs h outward.

Disconnect the harness from connector UCW9 of
the power / CD switch board.

1.

2.

Prior to performing the following procedure, remove
the top cover, the side covers, the CD tray fitting and
the front panel assembly.

Removing the power / CD switch board

(See Fig.27)

Disconnect the card wire from the mechanism board
of the cassette mechanism assembly.

Remove the seven screws V attaching the cassette
mechanism assembly.

1.

2.

Removing the cassette mechanism
assembly (See Fig.30)

<Front panel assembly>

Pull out the MIC level knob toward you.
Remove the two screws U attaching the

MIC/headphone board.

1.

2.

Removing the MIC/headphone board

(See Fig.28 and 29)

Prior to performing the following procedure, remove
the front board.

Fig.27

Fig.28

Fig.29

Fig.30

Tab h

Power / CD
switch board

S

T

MIC/
headphone
board

Tab h

Tab h

Cassette mechanism assembly

JW1

S

T

T

T

T

T

Front board

Mechanism board

Front panel assembly

Volume knob

MIC/headphone board

U

Cassette mechanism assembly

Mechanism board

V

V

V

V

UCW9

MIC level knob

1-13

MX-J170V

<CD changer unit>

Prior to performing the following procedure, remove
the CD changer unit.

Removing the VCD board

(See Fig.31)

1.

Disconnect the harness from connector PCON1 of
the VCD board .

2.

Remove the four screws W attaching the Sealed and
VCD board.

Removing the CD tray (See Fig.32 to 34)

1.

Turn the black loading pulley gear marked c 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.

W

PCON1

Shield

Fig.31

W

VCD board

2.

Disconnect the card wire from connector SCW5 of
the CD servo board on the upper side of the CD
changer unit.

3.

Push down the two tray stoppers marked i and pull
out the CD tray.

Loading pulley gear marked c

CD tray

Fig.32

Tray stopper marked i

CD tray

Tray stopper marked i

CD servo board

SCW5

Fig.33

CD tray

1-14

Fig.34

Prior to performing the following procedure, remove
the CD tray.

Release the two tabs j attaching the sensor board on
the under side of the CD tray.

Disconnect the harness from connector CW1 on the
sensor board and release the harness from the two
hooks k. Remove the sensor board.

Remove the screw X attaching the tray turn table.
Detach the tray turn table from the tray.

Pull outward the tab m attaching the tray turn table
motor assembly on the upper side of the tray and
detach the tray turn table motor assembly from the
tray.

1.

2.

3.

4.

Removing the sensor board / the tray
motor (See Fig.37 to 39)

Align the gear-cam with the gear-tray as shown
fig.28, then mount the CD tray.

When assembling the CD tray, take extreme care not
engage with gear - synchro.

1.

2.

Reinstall the CD tray (See Fig.35 and 36)

Fig.35

Gear-convert

Gear-convert

Gear-cam

Gear-tray

Gear-tray

Gear-tray

Gear-cam

timing point

Fig.36

Gear-synchro

CD tray

Fig.38

Fig.37

Fig.39

Tab j

Tab j

Hooks k

Sensor board

CW1

Tray turn table

Tray

X

Tray turn table motor

assembly

Tab m

MX-J170V

1-15

MX-J170V

Removing the belt, the CD servo board
and the switch board (See Fig.40 and 41)

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.

3.

Disconnect the motor wire harness from connector
on the CD mechanism board.

4.

Remove the two screws Y attaching the CD servo
board. First release the n side of the two tabs n and
two tabs o attaching the CD servo board motor to
raise the CD servo board slightly, then release the o
side.

If the tabs n and o are hard to release, it is
recommendable to unsolder the two soldered parts
on the motor terminal of the CD servo board.
Disconnect the terminal CW3 connected to the
switch board and remove the CD servo board.

Tabs p

Fig.40

Y

CD servo board

Belt

CD changer unit

Tabs o

Soldered parts

Motor

Tabs n

5.

Remove the screw Z attaching the CD Changer unit
and release the three tabs p attaching the switch
board outward and detach the switch board.

Z

Switch board

CW3

CD mechanism board

motor connecter

Pickup unit connector

Fig.41

1-16

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.

Remove the screw A 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.

Turn the CD mechanism holder assembly half
around the lift up slide shaft r of the CD mechanism
holder assembly until the turn table is reversed, and
pull out the CD mechanism holder assembly.

1.

2.

3.

Removing the CD mechanism holder
assembly (mechanism included)

(See Fig.42 to 45)

Fig.42

Fig.43

Fig.45

Fig.44

Motor connecter

CD mechanism assembly

CD changer unit

Pickup unit connector

A

CD mechanism holder assembly

Stopper

CD mechanism holder assembly

Lift up slide shaft r

Lift up slide shaft

CD mechanism holder assembly

MX-J170V

1-17

MX-J170V

<CD mechanism section>

•

Removing the CD mechanism holder from the CD
chassis to remove the CD mechanism.
(Refer to "Removing the CD mechanism holder
assembly" (Pag.2-11))

Removing the pickup unit.

1. Loosen the two screws A fixing the chassis.(Fig.1)

2. Removing the feed gear stopper c on the
bottom of the mechanism and pull out the gear.
(Fig.1, Fig.3, Fig.4)

3. Pull out the shaft by opening the pickup shaft
stopper outward to unlock.(Fig.1, Fig.2)

4. Removing the pickup unit.(Fig.1)

Removing the motor board.

1. Unsolder the motor terminal on the motor board.(Fig.3)

2. Remove the motor board.(Fig.3)

Removing the feed motor.

Remove the two motor fixing screws at B and
removing the feed motor.(Fig.1, Fig.3)

Removing the spindle motor.

The spindle motor cannot be removed as a single unit.
When removing the spindle motor, change the chassis
and turntable together as aunit.(Fig.5)

Stopper

A

A

Stopper

Shutter

Pickup unit

B

Fig.1

Fig.2

Shaft

Feed Gear

Shaft

Screw

W

Turn table

Screw

Spindle motor

Motor board

Feed motor

Spindle motor

Unsolder

c

Unsolder

Fig.3

c

1-18

B

Chassis

(Feed gear stopper)

Fig.4Fig.5

MX-J170V

<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.

Fig.1

Fig.2

Fig.3

Fig.4

R/P Head

R/P Head

E. Head

Spring

Stopper

Pinch roller
assembly

A

A

B

B

C

Pinch roller

Pinch roller

stopper

Pinch roller

Pinch roller

spring

Return spring

Return spring

Return spring

1-19

MX-J170V

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. Unsolder the four parts a on the solenoid

coil terminal.(Fig.5)

2. Remove the two screws E fixing the board.(Fig.5)

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

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)

a

E

Drive belt

Mecha.

board

b

Motor

terminal

Motor

Fig.5

E

D

D

Drive belt
Fig.6

Drive belt

b

a

Motor

1-20

Sleeve

Flywheel

c

Washer

Sleeve

d

FR belt

Capstan

washer

Flywheel

Fig.7

FR belt

Fig.8Fig.9

Capstan

washer

Flywheel

Adjustment method

Tuner

MX-J170V

Adjustment Location of Tuner PCB

*

ITEAM

Received FREQ.

Adjustment
point

Output

AM(MW) OSC Adjustment

520~1720 KHz

Adjustment

Non-

1~7.0±0.5V

MAIN
PCB

VT GND

AM(MW) RF Adjustment

590 KHz

MW -ANT

Maximum Output(Fig1-4)

TESTER

Fig 1-4 OSC Voltage

1-21

MX-J170V

FM THD Adjustment

SSG FREQ.

98 MHz

Adjustment
point

FM DETECTOR COIL

(TL3)
Output

60 dB

Minumum Distortion (0.3% below)
(Figure 1-1)

FM Search Level Adjustment
SSG FREQ.
Adjustment

point

(TSR1)

Output

BEACON
SENSITIVITY
SEMI-VR(20K½)

28 dB(±2dB)

98 MHz

Output
GND

FM S.S.G

FM
Antenna
Terminal

Speaker
Terminal

SET

Input

output

Distortion Meter

Figure1-1 IF CENTER and THD Adjustment

FM Antenna

SET

FM IN

FM S.S.G

28 dB

GND

Oscilloscope

Input

Adjust TSR1 so that “TUNED” of FL T
is lighted (Figure 1-2)

*Adjust FM S.S.G level to 28dB

AM(MW) I.F Adjustment

SSG FREQ.
Frequency

450 kHz
520 kHz

Adjustment
point

AM I.F COIL

(TL2)

Maximum output (Figure 1-3)

Figure1-2 FM Auto Search Level Adjustment

60cm

OUTPUT

AM SSG
450KHZ

INPUT

AM ANT
IN

Speaker Terminal

OUTPUT

VTVM Oscilloscope

Figure1-3 AM I.F Adjustment

20 k½

TL2

1-22

1. To adjust tape speed

Cassette deck

(GND)

VTVM

1) Measuring tape: i) MTT -111 (or equivalent)
(Tapes recorded with 3kHz)

ii) MTT-5512 (or equivalent)

2) Connect the cassette deck to the frequency counter

as in figure 1-5.

Notes

NOR
SPEED
Control

1

OUT
(connected
to the frequency
counter)

Turn UVR2 to
left and right
(FRONT PCB)

3KHz

Remark

Standard

To Adjust

Pre-Setup

Item

Step

Pre-Setup
Condition

1) Deck 1:MTT-111

2) Press PLAY
SW button

3) Deck 2:Same
as above

Cassette Deck

output

SPK OUT

Frequency Counter

Figure 1-5

Figure 1-6

SPK OUT

Recording /Play head

FWD PLAY

REVERSE PLAY

AZIMUTH control screw

Figure 1-7

In Out

Cassette Deck

Oscilloscope

±1%
range

Figure 1-8

Audio OSC.

SET
(MAIN PCB)

Oscilloscope

AUX IN

LINE OUT

VTVM

IN

DW2

IN OUT

TP

MX-J170V

1-23

MX-J170V

2. To adjust playback lebel/REC

Notes

1) Before the actual adjustment, clean the play/recording
head.

2) Measuring tape :
i) MTT -114NA(or equivalent 12.5kHz AZIMUTH control)
ii) MTT-5512

3) The cassette deck is connections as shown in figure 1-7.

1 Adjust Deck 1 Play Level

Step

1

Item

AZIMUTH

Pre-Setup
Condition

TP1 OUT
(VTVM is
connected to
the scope)

Pre-Setup

After putting MTT­114NA into Deck 1

- Press FWD PLAY
button.

2 Adjust Deck 2 Play Level/REC BIAS

Step

1

Item

AZIMUTH

Pre-Setup
Condition

TP1 OUT
(VTVM is
connected to
the scope)

Pre-Setup

After putting MTT ­114NA into Deck 2

1)Press FWD PLAY
button.

2)Press REV PLAY
button.

To Adjust

- Turn the control
screw to as shown
in Figure 1-6.

To Adjust

- Turn the control
screw to as shown
in Figure 1-6.

Standard

Max output
and same phase
(both channels)

Standard

Max output
and same phase
(both channels)

Remark

After
adjustment
secure it with
REGION
LOCK.

Remark

After
adjustment
secure it with
REGION
LOCK.

1-24

2

Recording
Bias
Voltage

Fig 1-8

After putting MTT­5512 into Deck 2

1)Press REC PLAY
button.

2)MAIN PCB DCW2,
connectted to VTVM

Turn DVR1,DVR2

to the right and left

7V(±0.5V)