Technics SU-X920D User manual

Table of contents

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-

Stereo

Integrated

Amplifier

ORDER

NO.

AD9203073A2

Service

Manual

Amplifier

SU-X920D

Colour

(Ke

a

eens

Black

Type

|

Areas

Suffix

for

Model

No.

|

Area

Colour

(E)

Europe

(EB)

Great

Britain

(K)

(EG)

Germany

and

Italy

Please

file

and

use

this

manual

together

with

the

Service

Manual

for

Model

No.

SU-X902,

Order

No.

AD9103052C2.

eThis

service

manual

indicates

the

main

differences

between

Original

SU-X902

(E).

@

LINE-UP

OF

COMPONENTS

SC-X920D

(EB)

}

|

RS-X920

(EB)

:

Cassette

Deck

SL-PJ38A

(EB)

:_CD

Player

(Made

in

MBV)

SL-

“OB

EE

:

Turntable

SB-CS95

(E

-

Speaker

(Made

in

PAES)

_

SC-X920D

(EF)

ST-X902LA

(

es

:

Tuner

(Made

in

PFS)

SU-X920D

(E)

:

Amplifier

SL-J110R

(E

SB-CS95

(E

ST-X902LA

(

a

SU-X920D

(EB)

RS-X920

(E)

:

Cassette

Deck

Technics

SL-PJ38A

(E)

:

CD

Player

(Made

in

MBV)

SL-J110R(E)

—_:

Turntable

_

SB-CS95(E)

_:_

Speaker

(Made

inPAES)

_

SC-X920D

(El)

RS-X920

(EG)

System

Name

Unit

|

System

Name

;

__Unit

ST-X902LA

(E)

_:

Tuner

|

ST-X902LA(EG)

:

Tuner

SU-

ae

:

Amplifier

|

SU-X920D

(EG):

Amplifier

SC-X920D

(E)

RS-X920

(E

:

Cassette

Deck

_

|

SC-X920D

(EG)

RS-X920

(EG)

-

Cassette

Deck

J

:

CD

Player

|

|

SL-PJ3B8A

(EG):

CD

Player

(Made

in

MBV)

_

:

Turntable

SL-J110R

(EG)

—:

Turntable

;

:

Speaker

(Made

in

PAES)

==

_|

SB-CS95(E)

tS

Speaker

(Made

in

PAES)

:

Tuner

-

“ST-X902LA

(El)

|

:

Tuner

(Made

in

PES)

a

Amplifier

SU-X920D

(EG)

:

Amplifier

:

Cassette

Deck

SL-PJ38A

(EG)

:

CD

Player

(Made

in

MBV)

4

SL-J110R

(EG)

>

Turntable

_|_SB-CS95(E)

-

Speaker

(Made

in

PAES)

_|

SU-X902

(Pages

34~39,

42

of

service

manual.)

CHANGES

@

CHANGE

IN

REPLACEMENT

PARTS

LIST

i

Part

Number

Ret.

No.

‘SU-X920D

Description

Remarks

SU-X902

(E)

(E,

EB,

EG)

TRANSFORMER(S)

r

1

[

RTP1P5E004-W

SLT5P268-W

POWER

TRANSFORMER

2

(EB)

|

JACK(S)

[____Jk902

[

83893338

|

$JS93328

AC

OUTLET

|

4

(EB)

CAPACITORS

f

C709

ECEAIHKA2R2B

|

ECEATHKN2R2B

CAPACITOR

50

V

2.2u

[CABINET

PARTS

3

SJP9205-2Y

$JP9205-2T

[

SHORTING

PIN

RGRO1050-A

REAR

PANEL

“[E)

Type

(A)

RGRO105C-E2

REAR

PANEL

(E)

Type

(B)

RGRO105P-A

REAR

PANEL

(EB)

Type

(A)

:

GROTOSC

A

RGRO105B-C2

REAR

PANEL

(EB)

Type(B}

RGRO1050-B

REAR

PANEL

(EG)

Type

(A)

RGRO105C-F2

|

REAR

PANEL

(EG)

Type

(8)

11

RMAO138

RMA0136-1

PLATE

13

FGLOO94-X

RGLO094-c

PANEL

LIGHT

21

AGUOATAAK

24

$JS9333A

$JS9332A

AC

OUTLET

COVER

(EB)

REMO0020-1

FAN

MOTOR

ASS'Y

Type

(A)

i

SYE

11282

SYE1128-4

|

FAN

MOTOR

ASS'Y

Type

(B)

28-1

=

SHE232-1

|

FAN

Type

(A)

RMQ0209-K

FAN

CASE

Type

(A)

26s

Suser

SHE233-1

(FAN

CASE

Type

(B)

28-5

SHE234

RMQ0208-K

CAP

Type

(A)

=

SJT783

TERMINAL

Type

(B)

28-7

—

|

suss215

CONNECTOR

(2P)

Type

(B)

28-8

[=

—

RMQ0212-K

TERMINAL

CAP

35

RFKGUX902E-K

RFKGUX920DEK

FRONT

PANEL

ASS'Y

40

a

RJS1A7402

T

CONNECTOR

(2P)

Type

(A)

41

a

XTBS3+8JFZ1

|

SCREW

Type

(A)

PACKING

MATERIALS

Pt

RPGO841

RPG1205

|

PACKING

CASE

i

i

P3

SPSD152

—

|

ACCESSORIES

BOX

ACCESSORIES

|

i

Al

ROF1096

—

T

INSTRUCTIONS

MANUAL

ASS'Y

()

RQT1494-B

|

INSTRUCTIONS

MANUAL

(EB)

|

At

REKSUX502E-K

RQT1493-D

~

TINSTRUCTIONS

MANUAL

(EG)

|

|

RFKSCX520DEK

INSTRUCTIONS

MANUAL

€)

i

A2

SJA187

—_

|

AC

POWER

SUPPLY

CORD

4.(E)

|

SU-X920D

SU-X920D

@

CONNECTIONS

OF

EACH

UNIT

.

There

are

two

types

of

the

fan

motor,

i.e:

Types

A

and

B.

Type

A...

The

fan

motor

terminal

is

a

connector

type.

The

“mark

®"”

is

printed

on

the

main

P.C.B.

of

type

A.

(Refer

to

the

diagram

below.)

Connection

diagrams

shown

are

for

connections

to

a

ey

REMOTE;

Turntable

Technics

histi

component

system.

:

Type

B...The

fan

motor

terminal

is

a

lead

wire

type.

SYNCHR

Make:

conriactions:in

the

numbered

sequential

order

‘

Refer

to

the

diagram

below

to

distinguish

type

A

from

type

B.

a

Connect

the

stereo

connection

cables

r

(included

with

the

turntabie,

tuner,

stereo

sound

pro-

Type

(A)

Type

(B)

cessor,

and

cassette

tape

deck),

Stereo

connection

cable

Rear

Panet

Rear

Panel

‘1-1

wey

“GND”

terminal

of

the

amplifier

This

terminal

is

for

use

with

a

turntable

which

has

a

ground

wire.

1-2

:

Fan

Motor

Ass'y

Fan

Motor

Ass'y

Connection

Via

Lead

Wires

Connector

“EXT”

terminals

of

the

amplifier

When

these

terminals

are

not

in

use,

be

sure

to

in-

sert

the

“shorting”

pins

(included).

OUT

EXT

iN

Direct

Connection

Via

Connector

Main

P.C.B.

Connector

Main

P.C.B.

Shorting

pins

Screw

[2]

Connect

the

L-type

cable

(included

with

the

turntable,

tuner,

stereo

sound

processor,

compact

disc

player,

and

cassette

tape

deck),

(2-4)

(Side

View)

(Side

View)

“REMOTE

OUT”

terminal

é

This

terminal

is

used

to

connect

to

the

“REMOTE

IN”

terminal

of

the

Technics

multi-compact

disc

player

(not

included).

Main

221

P.C.B.

“CONTROL”

terminal

Make

a

connection

from

this

terminal

to

the

“CON-

TROL”

terminal

tor

a

cassette

deck

on

a

Technics

multi

compact

disc

player.

(For

detailed

information,

refer

to

the

operating

in-

structions

of

the

Technics

multi

compact

disc

player.)

[3]

Connect

the

optical-tiber

cable

(included

Rear

Panel

Rear

Panel

with

the

compact

disc

player),

(34)

(Top

View)

(Top

View)

“DIGITAL

IN”

(CD,

DAT)

terminals

of

iz

the

amplifier

:

These

terminals

are

protected

by

the

dust-protec-

tion

caps

to

avoid

damage

by

the

dust,

etc.

Remove

the

caps

only

when

the

“DIGITAL

IN"

ter-

minais

are

to

be

used.

When

these

terminals

are

not

being

used,

attach

the

caps

as

shown

in

the

illustration

below.

Stereo

sound

rocess:

P

The

mark

@®

is

printed.

Bs

ee

Motor

)

Ass'y

LINE

OUT®

<

"f

DIGITAL

iT

OUT

out

Dust-protection

cap

22

@

Connect

the

AC

power

supply

cords

and

AC

outlet

See

page

3

of

service

manual

RS-X920,

Order

No.

AD9203069A2.

|

SU-X920D

SU-X920D

|

m

DISASSEMBLY

INSTRUCTIONS

Fat

Ne:

Peat

of

the

Fan

Motor

Ass’y

<=

i

a

Procedure

138-14

Hole

SS

‘

Fan

Case

Terminal

Cap

Projection

.

1.

Release

the

3

claws.

(See

Fig.

1.)

(Fig.

4)

2.

insert

a

screwdriver

at

the

root

of

the

fan.

Force

it

out

of

(Fig.

6)

NS

the

motor

shaft.

(See

Fig.

2.)

3.

Remove

the

cap

by

using

©

screwdriver.

(See

Fig.

3.)

a

\

4.

Remove

the

terminal

cap

in

the

direction

of

arrow.

Motor

I.

A

(See

Fig.

4.)

%

i

\r

)

5.

Remove

the

motor

from

the

fan

case.

(See

Fig.

5.)

I)

a

6.

When

mounting

the

motor,

align

the fan

casing's

we

}

projection

with

the

hole

of

the

motor.

(See

Fig.

6.)

Fan

Case

(Fig.

5)

Procedure

1-814

4

es

:

4

(Fig.

1)

ae

|

Fan

Case

Projection

i

(Fig.

5)

(Fig.

4)

1.

Remove

the

1

connector

(J551).

3.

Insert

a

screwdriver

at

the

root

of

the

cooling

fan.

2.

Release

the

3

claws.

(See

Fig.

1.)

Force

it

out

of

the

motor

shaft.

(See

Fig.

2.)

.

Remove

the

cap

by

using

©

screwdriver.

(See

Fig.

3.)

.

Remove

the

motor

trom

the

tan

casing.

(See

Fig.

4.)

.

When

mounting

the

motor

fan,

align

the

fan

casing’s

projection

with

the

hole

of

the

motor.

(See

Fig.

5.)

NM

m@

CABINET

PARTS

LOCATION

(Type

A)

(Type

B)

Note:

The

different

parts

between

type

A

and

type

B

are

enciosed

by

the

dot

lines

in

the

above

diagrams.

Printed

in

Japan

F920311500FF/YU/TN

SU-X902

m@

CONTENTS

Page

Circuit

board

diagram

2.2...

26...

eee

ee

eee

rece

22~27

Termiani

guide

of

IC's,

transistors

and

diodes

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

27

Wiring

connection

diagram

........

6.2.6

e

cece

ee

eter

eee

28

Function

of

IC

terminais

...........

02

eee eee

eee

ee

eee

29,

30

j

Block

diagram

2.66...

eee

eee

31~33

Digitalization

of

audio

signals

Replacement

parts

list

.....

34~39,

42

Disassembly

instructions

oe

‘

Cabinet

parts

location

.....

Ling

Sb

ds

dee

Beaten

sinaes

40,41

Schematic

diagram

.....

ee

we

a

Packaging

0.0.00...

6.6

e

cece

e

eee

eter

n

een

e

ert

en

eee

42

Description

of

FL

panel

@

BEFORE

REPAIR

(1)

tod

off

the

power

supply.

Using

a

100,

5

W

resistor

connect

both

ends

of

power

supply

capacitors

(C711,

C712,

3300

pF)

in

order

to

discharge

the

voltage.

(2)

Before

turning

the

power

supply

on,

after

completion

of

repair,

slowly

apply

the

primary

voltage

by

using

a

power

supply

voltage

controller

to

make

sure

that

the

consumed

current

at

50

Hz/60

Hz

in

NO

SIGNAL

mode

should

be

shown

below

with

respect

to

supply

voltage

220

V/240

V.

Power

supply

voltage

AC

240

V

Consumed

current

50

Hz

198~463

mA

186~434

mA

Consumed

current

60

Hz

181~422

mA

m@

PROTECTION

CIRCUITRY

The

protection

circuitry

may

have

operated

if

either

of

the

following

conditions

is

noticed:

*No

sound

is

heard

when

the

power

is

switched

ON.

*Sound

stops

during

a

performance.

The

function

of

this

circuitry

is

to

prevent

circuitry

damage

if,

for

example,

the

postive

and

negative

speaker

connection

wires

are

“shorted”,

or

if

speaker

systems

with

an

impedance

less

than

the

indicated

rated

impedance

of

this

unit

are

used.

If

this

occurs,

follow

the

procedure

outlined

below:

1.

Switch

OFF

the

power.

2.

Determine

the

cause

of

the

problem

and

correct

it.

3.

Switch

ON

the

power

once

again.

Note:

When

the

protection

circuitry

functions,

the

unit

will

not

operate

unless

the

power

is

first

switched

OFF

and

then

ON

AGAIN.

m

ACCESSORIES

@AC

power

supply

Cord

2.0...

eect

eet

1

Configuration

of

AC

power

supply

cord

differs

according

to

area.

SJA187

...

For

(E)

(EG)

area

only

SJA188........55

For

(EB)

area

only.

@

LOCATION

OF

CONTROLS

[1]

Power

switch

(POWER)

[2]

Speaker

selectors

(SPEAKERS)

[3]

Muting

indicator

(MUTING)

{4]

Volume-level

indicator

(VOLUME

LEVEL)

[5]

Volume

control

(VOLUME)

[6]

Sampling

frequency

indicators

(SAMPLING

FREQUENCY)

Surround-sound

button/indicator

(SURROUND)

Tone

controls

(BASS/TREBLE)

[9]

Balance

control

(BALANCE)

Volume

preset

button

(VOLUME

PRESET)

[ii]

Input

selectors/indicators

Super

bass

level

control

buttons/indicators

(SUPER

BASS

LEVEL)

[13]

Super

dynamic

sound

button/indicator

(S.

DYNAMIC

SOUND)

Super

bass

button/indicator

(SUPER

BASS)

Headphones

jack

(PHONES)

Active

current

sensor

switch

Phono

input

terminal

Tape

rec

out/playback

terminal

Tuner

input

terminal

[20]

CD

input

terminal

DAT

recout

terminal

VCR

recout/playback

terminal

[3]

EXT

output/input

terminal

(24)

VDP

input

terminal

[25]

MONITOR

terminal

[26]

System

control

IN/OUT

terminal

Control

terminal

(to

turntable)

GND

terminal

VCR

out/in

terminal

[30]

Cooling

fan

Bi]

Surround-sound

speaker

terminal

32]

Main

speaker

A

terminal

[33]

Main

speaker

B

terminal

[4]

CD

digital

input

terminal

[35]

DAT

digital

input

terminal

[36]

AUX

digital

input

terminal

AC

outlet

AC

iniet

SU-X902

m@

CONNECTIONS

2,

conniegions

ta

each

component

the

systetn

by

using

tered:

connection

cable

(not

included)

See

the

operating

instructions

of

the

tuner

(ST-X902L)

for

details.

Stereo

connection

cabie

White

(L)

Red

(R)

=

CONTROL

[SYSTEM

CONTROL

IN|

[SYSTEM

CONTROL

OUT}

Connecting

audio

components

Connect

a

stereo

sound

processor.

Stereo

sound

processor

(not

included)

LUNE

IN

LINE

OUT

©

Note:

When

these

terminalis

are

not

in

use,

be

sure

to

insert

the

“shorting”

pins

(included).

Mi

“SYSTEM

CONTROL

OUT”

terminal

This

terminal

is

used

to

connect

a

Technics

tape

deck

with

the

“SYSTEM

CONTROL

IN”

terminal.

“PHONO”

terminals

Sat

Connect

a

turntable.

®

i)

is

OUTPUT

INPUT

“Shorting”

pins

©

(“TUNER™

terminals

~~

Connect

a

tuner.

Turntabie

(not

included)

Tuner

{not

included)

AS

TCS

LE

SARE

Y

g

:

ait

®@

H

7

0

—

Hi

“GND”

termina!

This

terminal

is

for

use

with

a

turntable

which

has

a

ground

wire.

Mi

“SYSTEM

CONTROL

IN”

terminal

This

terminal

is

used

to

connect

a

Technics

tuner

with

the

“SYSTEM

CONTROL

OUT”

terminal.

@

“CONTROL”

terminal

This

terminal

is

used

to

connect

a

Technics

turntable

with

the

“REMOTE/SYNCHRO

REC"

terminal.

SU-X902

Make

connections

to

each

component

by

using

stereo

connection

cables

(not

included)

and

video

connection

cables

(not

included).

VCR

(not

included)

AUDIO

IN

AUDIO

OUT

input

outrut

LO

woeo

@

=

Rg

e

R)

(O(RALYVIDEO)(VIDEO)

(VIDEO)(VIDEO)

(ROR

Connect

a

TV.

MONI-

TOR

©)

TV

(not

included)

©

(_<vpp”

terminats

Connect

a

video

disc

player.

vor

a

i

{

RM

vo

(VIDEO)

®

&

(video)

4

4

4

3

eeeenene

A

Video

disc

player

(not

included)

AUDIO

OUT

VIDEO

OUT

RG

@t

©

let

(“AC

OUTLE

Do

not

connect

video

equipment

(such

as

a

TV,

etc.)

to

the

AC

outlet

of

this

unit.

(This

outlet

is

intended

for

audio

equipment.)

Do

not

exceed

the

indicated

power

ratings

when

connecting

to

this

outlet.

“UNSWITCHED”

outlet:

Power

is

always

available,

regardless

of

power

switch.

Audio

equipment

rated

up

to

60

W

can

be

connected

here.

Note:

The

configuration

of

the

AC

outlet

differs

according

to

area.

AC

power

supply

cord

Connect

the

AC

power

supply

cord

(included)

after

all

other

cables

and

cords

are

connected.

Notes:

Configuration

of

the

AC

outlet

and

AC

power

supply

cord

differs

according

to

area.

¢

If

this

unit

is

not

to

be

connected

with

the

tuner,

the

cord

is

to

be

connected

to

the

househoid

AC

outlet.

Tuner

(not

included)

[

|

AC

power

supply

cord

(inctuded)

This

unit

(eS)

For

United

Kingdom—————

plug.

Household

AC

outlet

Cut

off

and

dispose

of

the

plug

and

replace

with

a

suitable

;

SU-x902.

|

Connect

a

digital

audio

tape

deck.

Recordings

can

be

made

to

the

digital

audio

tape

deck.

Digita!

audio

tape

deck

{not

included)

Optical-fiber

cable

(not

included)

©)

(

“Aux”

terminal

(DIGITAL)

Connect

a

second

compact

disc

player,

etc.

Second

compact

disc

player

(not

included)

COAXIAL

C)

out

Q

Coaxial

cable

(not

included)

Connect

a

compact

disc

player.

Compact

disc

player

(not

included)

6

Optical-fiber

cable

(not

included)

}

©

Cer"

terminals

ANALOG

—~*S

Connect

a

compact

disc

player.

Compact

disc

player

(not

included)

Wi

“DIGITAL

INPUT”

(DAT,

CD)

terminals

of

this

unit

These

terminals

are

protected

by

dust-protection

caps

to

avoid

damage

by

dust,

etc.

Remove

the

caps

only

when

the

“DIGITAL

INPUT”

terminals

are

to

be

used.

When

these

terminals

are

not

being

used,

attach

the

caps

as

shown

in

the

illustration

at

right.

OPTICAL

C3

our

—

LINE

OUT

()

@

Qo

9

®

—

0

Dust-protection

cap

[ACTIVE

CURRENT

SENSOR]

ACTIVE

ON

“-CURREN

OFF

30

SENSOR

i

SU-X902

SPEAKERS)

\——~

SPEAKERS

(8

~

16

Q)-——

Connection

of

speaker

systems

Three

pairs

of

speaker

systems

(main,

second,

surround-sound)

can

be

connected

to

this

unit.

Speaker

systems

that

can

be

connected

to

any

of

the

speaker

connection

terminals

of

this

unit

are

speaker

systems

with

an

impedance

of

8

to

16

ohms.

Make

connections

to

each

speaker

system

by

using

speaker

cords

(not

inctuded).

Main

speaker

systems

(not

included)

|:

-

Connect

to

the

“A”

terminals.

(right)

Ho

OW

Second

speaker

systems

(not

included)

Connect

to

the

“B"

terminals.

(right)

(left)

Wo Of

Connect

to

the

“SURROUND”

terminais.

Be

sure

to

connect

both

speaker

systems.

If

only

one

side

is

connected,

no

sound

will

be

heard.

(right)

The

selector

is

used

to

enjoy

powerful

super-bass

sound.

ON:

Switch

ON

when

connecting

the

Technics

system

speakers

(SU-X902:

SB-CS90,

SU-X502:

SB-CS90/CS70).

OFF:

Switch

OFF

when

connecting

speakers

other

than

Technics

system

speakers.

Notes:

¢

When

connecting

speakers

other

than

system

speakers,

sound

from

the

speakers

may

not

be

heard

if

the

selector

is

pressed

ON,

because

the

protecting

circuit

on

the

amplifier

becomes

active.

*The

active

current

sensor

activates only

for

the

speaker

systems

connected

to

the

“A”

terminais.

es

connect

cords

to

terminals

————-——_,

@®

Strip

off

the

outer

®

covering,

and

twist

the

center

conductor.

SC

i———-~_

15mm

Twist

@

Tilt

the

fever

back

and

(19/32")

insert

the

cord.

5

*

@:

Close

the

lever

and

pull

ice

the

cord

gentty

to

be

sure

that

it

is

secure.

Note:

Be

sure

to

only

connect

positive

(+)

cords

to

positive

(+)

terminals,

and

negative

(—)

cords

to

negative

(—)

terminals.

Note:

To

prevent

damage

to

circuitry,

never

short-circuit

the

plus

(+)

and

minus

(—)

speaker

wire.

SU-X902

m@

DIGITALIZATION

OF

AUDIO

SIGNALS

MWhy

digitize?

*

Audio

signals

are

analog

signals

with

a

continuous

form.

*

When

these audio

signals

are

subjected

to

repeated

electronic

processing

(recording,

playback,

etc.),

they

become

noisy

and

distortion

occurs,

thus

resulting

in

deterioration

of

the

sound

quality.

«When

these

signals

are

first

digitized

before

processing,

they

have

the

foliowing

advantages

that

prevent

deterioration

of

the

sound

quality:

@

Resistance

to

noise

®

Extremety

low

distortion

®

Fiat,

even

frequency

response

Analog

signals

Original

sound

Deteriorated

signal

Digital

signals

a

i

>

Even

if

noise

occurs

SLU

Processed

as

uniform

series

of

Os

and

1s,

without

distortion.

NUL

+

Original

sound

Digitalization

example

(recording

to

CD

and

play

of

CD)

Recording

to

CD

Analog

signals

XN

<>

CD

play

Compact

disc

player

a>}

Mb

oo

|—

Digital/analog

conversion

Analog

signals

—_—_—_—

Analogidigital

conversion

TULL

Amplifier

ae

W

How

signals

are

digitized

If

it

is

known

to

what

degree

of

minuteness

the

human

ear

can

distinguish

sounds,

it

is

then

possible,

by

using

that

data

as

the

standard

reference,

to

digitize

them

by

dividing

analog

signais

into

minute

pieces,

after

which

they

can

be

transmitted

with

a

high

degree

of

precision,

and

thereafter

recorded

and

played

back

in

the

digitized

format.

Analog

signals

are

sampled,

quantified

and

encoded.

g

23

os

&

&

Time

2

Sampling:

3

cy

i

Analog

signals

are

minutely

sub-

as

divided

on

the

lateral

axis.

Es

qs

o

|}

Quantification:

3

ey

=

Sampled

signals

are

minutely

é

s

sub-divided

on

the

vertical

axis.

o

>

Digital

signals

Recorded

to

CD

"il

—

=

Digital

signals

Speaker

systems

econ

ee

|

Sound

deterioration

may

easily

occur

because

analog

signals

are

sent

to

the

amplifier

through

stereo

connection

cables.

Speaker

systems

This

method

mpact

disc

player

_—

sn

Amplifier

Digital/anaiog

conversion

+4

1]

Sound

deterioration

does

not

easily

occur

tecause

digital

signals

are

sent

to

the

amplifier

through

optical-fiber

cable.

(|

What

the

sampling

frequency

is

)

The

sampling

frequency

expresses

the

degree

of

minuteness

to

which

signals

can

be

cut,

relative

to

a

certain

specified

time

interval,

during

sampling.

For

compact

disc

sound:

Analog

signals

are

cut

44,100

times

(i.e.,

44.1

kHz)

during

one

second.

This

44.1

kHz

is,

therefore,

the

sampling

frequency

for

compact

disc

sound.

(|

What

analog/digital

conversion

is

)

Audio

signals

(analog

signals)

are

taken

out

(sampled)

at

certain

fixed

time

intervals.

The

points

at

which

this

sampling

frequency

occurs

are

digitally

encoded

and

converted

to

digital

signals.

What

digital/analog

conversion

is

)

Each

sampling

frequency

point

is

returned

(converted)

to

voltage.

thus

converting

digital

signais

to

the

analog

signais

that

we

can

hear.

@

DISASSEMBLY

INSTRUCTIONS

|

SU-X902

Removal

of

the

Cabinet

Procedure

Ref.

No.

1

1.

Remove

the

6

screws

(@~

@)-.

2.

Remove

the

cabinet

in

the

direction

of

the

arrow.

Removal

of

the

Power

Switch/Speaker

Select

Switch

P.C.B.

Ref.

No.

3

Procedure

1-2-3

Power

switch/Speaker

select

switch

P.C.B

Remove

the

2

screws

(@,

@).

Procedure

Ref.

No.

2

Removal

of

the

Front

Panel

Unit

12

J501

1.

Remove

the

2

connectors

(J501, J502).

—Removal

of

the

Connector—

\

Fiot

cable

4

Connector

ef

2.

Remove

the

3

screws

(@~®).

3.

Remove

the

front

panel

unit

in

the

direction

of

the

arrow.

Ref.

No.

4

Removal

of

FL

Drive

P.C.B.

Procedure

QO

i

1.

Remove

the

4

knobs

(@~@).

2.

Remove

the

4

nuts

(@~

@)

J63IA

J632A

3.

Remove

the

3

screws

(Q@~

@®).

4.

Remove

the

3

connectors

(J631A,

J632A.

J633A)

i

Len

enna

eRe

NRaREAeE

Nee

Ne

ROE

TAR

AE

an

ot

a

SU-X902

ees

Removal

of

the

Operation

P.C.B.

ee

Removal

of

the

Operation

Buttons

Procedure

Procedure

1245

?

+

rf

1324-56

?

Tens

Button:

“Lens

5

Button

{

:

1.

Remove

the

4

screws

(@~Q).

Lens

2.

Release

the

4

claws

in

the

direction

of

the

arrow.

Pull

out

the

operation

buttons

and

lens.

Ref.

No.

Removal

of

the

Sampling

7

Frequency

Indicator

Lens

Procedure

1-247

@Release

the

2

claws.

Removal

of

the

Rear

Panel

Procedure

18

Procedure

1-9

Release

the

4

claws.

~10-

SU-X902

System

input/output

P.C.B.

Removal

of

the

P.C.B.s

Procedure

®

Removal

of

the

D/A

converter

P.C.B.

1.

Remove

the

screw

(@).

2.

Remove

the

D/A

converter

P.C.B.

in

the

direction

of

the

arrow.

AUX

P.C.B.

S

Video

input/output

@

Removal

of

the

other

P.C.B.

P.C.B.

Remove

the

P.C.B.

in

the

direction

of

the

arrow.

Check

of

the

main

P.C.B.

Procedure

e

111

|

D/A

converter

P.C.B.

1.

Remove

the

7

screws

(~@).

5.

Remove

the

bottom

chassis.

6.

Reinstall

the

front

panel

unit

to

the

main

P.C.B.

3.

Remave

the

3

screws

(@~@®).

4.

Remove

the

front

panei

unit

in

the

direction

of

the

arrow.

“Connect

2

flat

cables

(J501A,

J502).

=

ft

PANA-05251

/

Oruckt

1.

Unsolder

the

power

IC

or

regulator

transistor.

2.

Remove

the

4

screws

(@~Q).

Regulator

When

mounting

the

power

IC,

or

regulator

transistor

apply

silicon

terminat

compound

(SZZOL15)

to

the

rear

of

the

power

IC

or

regulator

transistor.

1.

Remove

the

1

connector

(J209).

2.

Release

the

3

claws.

Removal

of

the

Power

IC

and

Regulator

Transistor

Power

transformer

1.

Remove

the

1

flat

cable

(J701).

2.

Remove

the

4

screws

(Q@~Q).

Projection

Fon

motor

3.

Insert

a

screwdriver

at

the

root

of

the

cooling

fan.

Force

it

out

of

the

motor

shaft.

.

Remove

the

motor

cover

by

used

©

screwdriver.

.

Remove

the

motor

from

the

fan

casing.

6.

When

mounting

the

motor

fan,

align

the

fan

casing’s

projection

with

the

hole

of

the fan

motor.

ae

Some

chassis

components

may

have

sharp

edges.

Be

careful

when

disassembling

and

servicing.

|

ATTENTION

SERVICER”

eReplacement

of

the

Foot.

1.

Remove

the

4

heat

melted

posts

on

the

chassis

with

a

pair

of

nippers

or

similar

tool.

2.

To

repiace

the

foot

(RKA001

1-2)

on

the

chassis,

melt

the

4

posts

with

a

soidering

iron.

Removal

of

the

Power

Transformer

Heat

Melted

Posts

Ls;

/

Ld

Foot

Chassis

te

Wj

\

a

a

sod

|

p——__Foot

(RKAGO1

1-2)

=12>