JVC PC-Y777 B Manuale utente

PC-Y777

B/E/G

=

SERVICE

MANUAL

PC-Y777

sec

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Continental

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West

Germany

Contents

Page

[1]

Safety

Precautions

...............ccccceenee

eee eec

teen

een

eeeee

2

Standard

Schematic

Diagram

......................0600

19

Safety

Precautions

about

PC-Y777

...............:45

3

[11]

Wiring

Connections

............:ccceeeeeeesesseeeeneenens

21

Features

.........ecceseceecnesecseeeeeseeceesentetenesereceeoees

4

Location

of

P.C.

Board

and

Parts

List

................

22

[4]

Specifications

2.0.0.0...

ccc

cece

ce

cece

cence

tent

en ee

eeeeeees

4

[13]

Exploded

View

of

Mechanism

Component

[5]

Name

of

Controls

and

Their

Functions

..............-

5

and

Parts

List

2.2.0.0...

cece

eee

nese

eee

ee

eee

rere

eeeeenene

28

[6]

Location

of

Main

Parts

...........cccceeseeeseeneeetees

7

Exploded

View

of

Enclosure

Assembly

Removal

of

Main

Parts

................ccececeeeeee

eee

eens

10

and:

Parts

List

o.cci0iccctscadewiiv

ected

qetasavae

seeders

saci

30

Main

Adjustments

.................cccceeeeeeeceeeeeeeeeeeees

12

[15]

Packing

Illustration

and

Packing

Parts

List

.........

34

[9]

Block

Diagram

..............c

cece

ccc

cc

nee

ee

eee

e

neces

eeeeee

18

No.

1802

July

1990

PC-Y777

B/E/G

|

2

~|1|

Safety

Precautions

1.

The

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

uniess

authorized

in

writing

by

the

manufacturer.

Replacement

parts

must

be

identical

to

those

used

in

the

original

circuits.

Service

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

manufacturer

or

responsibility

for

personal

injury

or

property

damage

resulting

therefrom.

3.

Many

electrical

and

mechanical

parts

in

the

product

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

(A\)

on

the

schematic

diagram

and

Parts

List

in

Service

Manual.

The

use

of

a

substitute

replacement

which

does

not

have

the

same

safety

characteristics

as

the

recommended

replace-

ment

part

shown

in

the

Parts

List

in

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

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

pro-

duct

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

part

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

0.5

mA

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

2

10

W

resistor

paralleled

by

a

0.15

uF

AC-type

capacitor

between

an

exposed

metal

part

and

a

known

good

earth

ground.

Measure

the

AC

voltage

across

the

resistor

with

the

AC

ET

Were

ons

cea

voltmeter.

or

more

sensitivity.)

Move

the

resistor

connection

to

each

exposed

metal

o

Sl

part,

particularly

any

exposed

metal

part

having

a

return

.

0.15

pF

AC

TYPE

path

to

the

chassis,

and

measure

the

AC

voltage

across

the

resistor.

Now,

reverse

the

plug

in

the

AC

outlet

and

‘

Blake

thiscorebe

repeat

each

measurement.

Any

voltage

measured

must

on

each

etpcaad

not

exceed

0.75

V

AC

(r.m.s.).

1500

2

10

W

metal

part.

This

corresponds

to

0.5

mA

AC

(r.m.s.).

Good

earth

ground

—Warning

.

This

equipment

has

been

designed

and

manufactured

to

meet

international

safety

standards.

.

It

is

the

legal

responsibility

of

the

repairer

to

ensure

that

these

safety

standards

are

mainteined.

.

Repairs

must

be

made

in

accordance

with

the

relevant

safety

standards.

.

It

is

essential

that

safety

critical

components

are

replaced

by

approved

parts.

.

If

mains

voltage

selector

is

provided,

check

setting

for

local

voltage.

oh

WON

=

(No.

1802)

|

PC-Y777

B/E/G

Safety

Precautions

about

PC-Y777

PRECAUTIONS

Prevention

of

damage

to

the

set

1.

Do

not

leave

this

unit

in

direct

sunlight

or

in

extremely

hot

(about

40°C

(104°F))

or

humid

places

or

in

closed

automobiles

in

the

sun.

2.

Exhausted

batteries

in

the

unit

may

cause

damage

due

to

corrosion.

When

the

unit

is

not

used

for

more

than

2

weeks,

remove

the

batteries.

3.

Never

use

benzine

or

thinner

for

cleaning

as

these

will

damage

the

cabinet.

4.

Place

the

unit

as

far

away

from

the

TV

as

possible.

Prevention

of

electric

shock

and

fire

hazards

1.

Even

when

the

POWER

switch

is

set

to

STANDBY,

a

very

small

current

will

flow.

To

save

power

and

for

safety

when

not

using

the

unit

for

an

extended

period

of

time,

disconnect

the

power

cord

from

the

household

AC

outlet.

2.

Do

not

handle

the

power

cord

with

wet

hands.

3.

When

unplugging

the

power

cord,

always

grasp

and

pull

the

plug,

not

the

power

cord.

CAUTION:

|

TO

REDUCE

THE

RISK

OF

ELECTRIC

SHOCK,

4,

Consult

your

nearest

dealer

when

damage,

disconnection

|

DO

NOT

REMOVE

COVER

(OR

BACK).

or

contact

failure

is

found

with

the

cord.

NO

USER-SERVICEABLE

PARTS

INSIDE.

REFER

SERVICING

TO

QUALIFIED

SERVICE

PERSONNEL.

The

lightning

flash

with

arrowhead

symbo!,

The

exclamation

point

within

an

equilateral

within

an

equilateral

triangle,

is

intended

to

triangle

is

intended

to

alert

the

user

to

the

alert

the

user

to

the

presence

of

uninsulated

Presence

of

important

operating

and

main-

“dangerous

voltage”

within

the

product's

tenance

(servicing)

instructions

in

the

litera-

enclosuré

that

may

be

of

sufficient

magni-

ture

accompanying

the

appliance.

tude

to

constitute

a

risk

of

electric

shock

to

persons.

B

Important

management

points

regarding

safety

A

@

(version

‘

only

z

(Items

Demanding

Special

Safety

Precautions)

gaat

:

1.

Make

sure

that

the

soldering

round

does

not

protrude

in

order

to

maintain

a

gap

between

the

primary

circuit

of

the

circuit

board

and

the

pattern

adjoining

the

primary

circuit.

2.

Confirm

that

the

power

transistor

is

provided

with

the

parts

number

‘’VTP57P2-12C/VTP57P2-12CBS"’,

and

to

prevent

the

pattern

from

coming

off,

confirm

that

the

fixation

screw

for

the

circuit

board

is

not

loose.

3.

Confirm

that

the

AC

socket

is

provided

with

the

number

“HSC

1466"

and

that

the

pattern

is

properly

fixed.

4,

Check

that

clamping

has

been

properly

performed

to

pre-

vent

contact

with

heated

parts.

5.

As

D999,

the

heat

sink

IC801,

802,911,

R751, R761,

R723,

R814,

R815,

R28,

Q914

and

0916

are

heated

parts,

make

sure

that

they

do

not

come

in

contact

with

the

wire

and

the

E.

cap.

6.

Confirm

that

fuses

F998

and

F997

‘’T4A”

“’250”

are

properly

maintained,

and

that

the

volume

indication

seal

‘

DTS

Board

ae co

aed

Tuo

d

T4A/125"

is

attached

the

fuse.

‘aprenne

oe

aes

Ti

Ts

7.

In

order

to

prevent

the

tuner

wire

from

contacting

the

Wire

primary

fuse,

check

that

the

wire

is

inseted

into

the

rib

and

that

it

is

fastened

with

bond.

8.

Make

sure

that

all

support

parts

are

bonded

and

fixed

with

spacers.

Amp

Board

(No.

1802)

3

PC-Y777

B/E/G

|

4

Features

1.

MW/LW/FM-stereo

PLL

synthesizer

tuner.

@

20-station

preset

tuning

(FM-10,

MW-5,

LW-5).

@

Seek/manual

tuning.

2.

Double-cassette

mechanism

(Deck

A

for

recording

and

playback,

Deck

B

for

playback).

¢

Dolby*B

Noise

Reduction

system.

Metal

and

CrO,

tape

can

be

played

back

for

superior

tone

quality.

Synchro

start

dubbing

function

(normal/high

speed

dubbing).

e

Relay

playback

(from

Deck

B

to

Deck

A).

3.

“LIVE

EFFEX”

Sound

System

for

the

reproduction

of

an

expanded

sound

field.

4.

Hyper-Bass

Sound

System

with

3D

super

woofer.

.

5-Band

graphic

equalizer

(S.E.A.)

controls.

.

CD

IN

jacks.

ac

*

Dolby

noise

reduction

manufactured

under

license

from

Dolby

Labo-

ratories

Licensing

Corporation.

“DOLBY”

and

the

double-D

symbol

[]{Jare

trademarks

of

Dolby

Labo-

ratories

Licensing

Corporation.

4]

Specifications

<Radio

Section

>

Frequency

:

FM

87.5—

108

MHz

PC-Y777

B

ranges

AM

522—1,629

kHz

e

FM

=

87.5—108

MHz

MW

=

522-—-1,629

kHz

-

SW

6—18

MHz

i

a

LW

144—288

kHz

FM

87.5—108

MHz

MW

=

522—1,629

kHz

:

SW

6—18

MHz

POMEL

LW

144—288

kHz

Antennas

:

Telescopic

antenna

for

FM

Ferrite

core

antenna

PC-Y777

B

for

AM

Telescopic

antenna

ina

eia

ante

(PC-Y777

E/G)

Ferrite

core

antenna

MW

&

LW

<Tape

Recorder

Section>

Track

system

:

4-track

2-channel

stereo

Frequency

:

40—14,000

Hz

response

(with

normal

tape)

Wow

&

flutter:

0.15%

(WRMS)

Fast

wind

time:

Approx.

120

sec.

(Deck

A:

C-60

cassette)

Approx.

120

sec.

(Deck

B:

C-60

cassette)

<General

>

3D

system

:

ASW

(Acoustic

Super

Woofer)

Power

output

10W

(5W

+

5W)

at

62

and

13

W

for

3D

at

8

Q

(Max.)

6

W

(3

W

+

3W)

at

62

and

7

W

for

3D

at

8

Q

(10%

THD)

S.E.A.

:

S.E.A.

center

frequencies:

characteristics

100

Hz/330

Hz/1

kHz/3.3

kHz/

10

kHz

S.E.A.

control

range:

+10

dB

(No,

1802)

“LIVE

EFFEX"”

Sound

System

When

stereo

sources

are

heard

from

the

speakers,

often

the

sound

feels

far

more

restricted

than

in

a

live

performance.

This

is

because

the

stereo

effect

is

degraded

due

to

crosstalk**

between

our

left

and

right

ears.

The

PC-Y999/Y777

removes

this

acoustic

cross-

talk

between

the

ears

using

our

newly

developed

“LIVE

EFFEX”

signal

sound

processor;

with

this,

the

sound

image

extends

beyond

the

speakers,

realizing

a

natural

stereo

sound

field.

**

Crosstalk

is

a

phenomenon

in

which

sound

from

two

channels

is

mixed;

in

addition

to

hearing

sound

from

the

right

speaker,

the

right

ear

hears

sound

from

the

left

speaker,

with

a

slight

time

delay.

Input

jacks

Output

jacks

:CD

IN

xX

2

(440

mV/50

kQ)

:

Speaker

x

2

(Matching

im-

pedance

6

—

16

)

Headphones

x

1

(15

mW/32

Q,

Matching

impedance

16

2—1

kQ)

:

DC

12

V

(8’°R20"'

batteries)

AC

240

V,

50

Hz

(PC-Y777

B)

AC

220

V,

50 Hz

(PC-Y777

E/G)

Ext.

DC

IN

12

V

(Car

battery

via

optional

CN-332

car

adapter)

Power

consumption

:

36

W

(with

POWER

SW

ON)

2.0

W

(with

POWER

SW

STANDBY)

:

650(W)

x

235(H)

x

235(D)

mm

including

knob

Power

supply

Dimensions

Weight

:

Approx.

6.9

kg

(without

batteries)

<

Speaker

Section

>

(each

unit)

Speaker

:10cmx

1

Impedance

7:60

Dimensions

:

155(W)

x

215(H)

x

195(D)

mm

Weight

:

Approx.

1.1

kg

Design

and

specifications

subject

to

change

without

notice.

|

PC-Y777

B/E/G

[5]

Name

of

Controls

and

Their

Functions

@

Front

panel

@

Top

panel

@

Rear

panel

@

Display

window

©

indicators

(for

tuner

operation)

BAND

indicator

(FM1-FM2-MW-LW)

Radio

frequency

display

Preset

station

indicator

STEREO

(FM

stereo)

indicator

@

BAND

button

©

Tuning

control

DOWN

frequency

UP

frequency

©

Preset

station

buttons

Cassette

holder

(Deck

A)

Cassette

hoider

(Deck

B)

@

VOLUME

contro!

®

Cassette

operation

buttons

(Deck

A)

O

REC:

Press

this

button

with

the

B®

PLAY

button

for

re-

cording.

bm»

PLAY:

Press

to

play

the

tape.

@<REW:

Press

to

rewind

the

tape

rapidly.

PP

rF:

Press

to

wind

the

tape

forward

rapidly.

m/SSTOP/EJECT:

Press

to

stop

the

tape.

Pressing

this

button

after

the

tape

stops

opens

the

cassette

holder.

SUPAUSE:

Press

to

stop

the

tape

temporarily.

Press

again

to

release

the

pause

mode.

@

HYPER-BASS

switch

and

3D

indicator

-m=

ON:

Set

to

this

position

to

listen

to

Hyper-Bass

Sound.

OFF:

Set

to

this

position

when

Hyper-Bass

Sound

is

not

required.

®

This

function

does

not

work

while

headphones

are

being

used.

@

LIVE

EFFEX

switch

and

LE

indicator

wm.

ON:

Set

to

this

position

to

listen

to

the

LIVE

EFFEX

sound.

OFF:

Set

to

this

position

when

the

LIVE

EFFEX

sound

is

not

required.

(No.

1802}

5

ih

si

pales

es

rh

ai

igen

ce

eiladllintadtin

PC-Y777

B/E/G

6

@®

Cassette

operation

buttons

(Deck

B)

>

PLAY:

Press

to

play

the

tape.

@<REW:

Press

to

rewind

the

tape

rapidly.

PPFF:

Press

to

wind

the

tape

forward

rapidly.

@/SSTOP/EJECT:

;

Press

to

stop

the

tape.

Pressing

this

button

after

the

tape

stops

opens

the

cassette

holder.

@

TAPE

(FOR

PLAYBACK)/FM

MODE

switch

TAPE

(FOR

PLAYBACK)

:

Set

this

switch

according

to

the

type

of

tape

to

be

used.

«m=.

METAL/CrO,

:

(Playback

only)

Set

to

this

position

to

listen

to

a

metal

(type

IV)

or

chrome

(type

II}

tape.

NORMAL:

Set

to

this

position

to

listen

to

a

normal

(type

|)

tape.

FM

MODE

switch:

-=

MONO:

Set

to

this

position

when

FM

stereo

reception

is

obscured

by

noise.

STEREO:

Set

to

this

position

when

listening

to

or

recording

an

FM

stereo

broadcast.

@

DOLBY

NR

switch

Set

to

ON

{

«=m

)

when

recording

or

playing

back

tapes

using

the

noise

reduction

system.

CONNECTIONS

@

Do

not

switch

the

power

on

until

all

the

connections

are

completed.

FM

outdoor

antenna

@

Headphones

jack

(PHONES)

(3.5

mm

dia.

stereo

mini

jack)

Connect

headphones

(impedance

1692

—

1k)

to

this

jack,

The

speakers

are

automatically

switched

off

when

headphones

are

connected.

@

POWER

switch

@

FUNCTION

switch

TAPE-NORMAL

SPEED

DUBBING:

Set

to

this

position

when

listening

to

a

cassette

or

dub-

bing

at

normal

speed.

TAPE-HIGH

SPEED

DUBBING:

Set

to

this

position

when

dubbing

at

high

speed.

TUNER:

Set

to

this

position

when

listening

to

or

recording

from

the

radio.

CD

IN:

Set

to

this

position

when

listening

to

or

recording

from

the

source

connected

to

the

CD

IN

jacks.

5-BAND

GRAPHIC

EQUALIZER

controls

(S.E.A.)

Memory

backup

battery

compartment

cover

Telescopic

antenna

for

FM

reception

BEAT

CUT

switch

EXT

ANT

terminal

for

FM

(PC-Y999E/Y777E)

@

CD

IN

jacks

Connect

a

CD

player.

@

SPEAKER

terminals

Connect

the

provided

speakers

to

these

terminals.

@

AC

IN

(AC

input)

jack

@®

DC

IN 12

V

jack

(

--®—+

)

(PC-Y999E/Y777E)

@)

Battery

compartment

cover

Signal

cord

provided

with

the

CD

player

{

To

LINE

OUT

jacks

CD

player

(optional)

*

Space

for

speaker

cords

After

connecting

the

speaker

cords,

bundle

any

slack

into

the

space

for

the

speaker

cords

in

the

rear

panel.

@

When

connecting

the

speaker

cords,

connect

the

one

marked

with

a

jine

to

the

‘-”

ter-

minal

first.

—)

®

Marked

with

line

Notes:

1,

Connect

the

connection

cords,

etc,

being

sure

not

to

confuse

channels

or

polarities.

The

wrong

connection

will

degrade

the

sound

quality

and

stereo

effect.

2.

Be

sure

to

connect

the

connection

cords,

etc.

correctly.

Otherwise,

there

will

be

no

sound

or

there

will

be

noise.

(No.

1802)

PC-Y777

B/E/G

o|

Location

of

Main

Parts

Speaker

terminal

Main.

board

CD

IN

jack

©,

Tuner

board

DC

IN

12.

V

Fig.

6-1

Beat

cut

switch

CD

IN

Beat

cut

switch

SEA

board

Tuner

board

TT

i

Main

board

Fig.

6-2

(No.

1802)

7

PC-Y777

B/E/G

|

DTS

board

ass’y

Mechanism

ass’y

Fig.

6-3

Graphic

equalizer

ass’y

Fig.

6-4

8

(No.

1802)

U

o)

1

~<

~J

si ie

wo

mi

Go)

~

Mechanism

[Al

~

Mechanism

[B]

~

RF

clutch

ass’y

RF

clutch

ass’y

t

Supply

reel

disk

Take

up

reel

disk

Supply

reel

disk

Take

up

reel

disk

\

CO.

os

|

A

|

Erase

head

Rec./playback

head

Main

belt

Playback

head

Fig.

6-5

Motor

ass’y

RF

clutch

ass’y

RF

clutch

ass'y

1

|

Flywheel

assy

P.

Kick

lever

(A)

Flywheel

ass’y

Fig.

6-6

(No.

1802)

9

PC-Y777

B/E/G

|

Removal

of

Main

Parts

@

Rear

Cover

1.

Remove

the

battery

cover

(main

battery).

2.

Remove

the

three

screws

@)

retaining

the

RCA

jack

and

top

side

of

the

rear

cover.

3.

Remove

the

five

screws

Q)

retaining

the

rear

cover

from

the

backside.

4.

Remove

the

two

screws

(3)

rataining

the

rear

cover

in

the

battery

box.

5.

Slightly

pull

out

the

rear

cover

and

remove

the

memory

battery

and

the

antenna

wire.

Memory

battery

.....

Preamplifier

circuit

board

Antenna

wire

.........

Tuner

board

@

Tuner Board

Assembly

1.

remove

the

connector

(CN3)

and

the

flat

wire

(CN1)

from

the

DTS

board.

2.

Remove

the

output

cord

from

CN3

of

the

preamplifier

board.

3.

Pull

out

the

tuner

board

assembly.

ks

|

Fig.

7-1

Function

knob

B

Graphic

Equalizer

Assembly

(SEA

assembly)

1.

Pull

the

G.

equalizer

assembly

rearward

and

remove

the

cabinet.

2.

Remove

the

connection

wire

from

CN703

of

the

preamplifier

board.

3.

Remove

the

one

screw

retaining

the

G.

equalizer

board

assembly.

i

:

i

|

3

]

!

{

|

.

@

3D

Assembly

(with

pre-

and

power

board

assemblies)

1.

Remove

the

function

switch

knob.

2.

Remove

the

one

screw

(4)

located

under

the

function

knob.

3.

Remove

the

one

screw

6)

retaining

the

right

side

of

the

cabinet.

4.

Pull

out

the

volume

knob.

.

Remove

the

two

screws

1)

under

the

3D

case.

6.

Release

the

head

wire

and

the

motor/switch

wire

from

the

preamplifier

board.

Motor/switch

wire

Power

amplifier

board

CN802

B.

mechanism

Back

view

oa

Preamplifier

CN701

Remove

the

head

wire

A.

mechanism

connector

.

Preamplifier

CN702

if

necessary

head

wire

7.

Pull

out

the

3D

assembly.

Preamplifier

Board

Assembly

1.

Remove

the

four

screws

6)

retaining

the

preamplifier

board.

2.

Remove

the

board

assembly

wire.

CN804

to

the

power

board.

CN707

to

the

preamplifier

board.

10

(No.

1802)

JVC PC-Y777 B Manuale utente

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