Panasonic SU-373 User manual

Service

Man

Stereo

Integrated

Amplifier

ORDER

NO.

HAD87051

20C1

Amplifier

SU-373

Color

(K)...Black

Type

SPECIFICATIONS

(IHF’

78)

M@

AMPLIFIER

SECTION

Rated

minimum

sine

wave

RMS

power

output

20

Hz~20

kHz

both

channels

driven

0.09%

total

harmonic

distortion

100W

per

channel

(8

ohms)

1

kHz

continuous

power

output

both

channels

driven

0.09%

total

harmonic

distortion

105W

per

channel

(8

ohms)

Dynamic

headroom

1.1

dB

(8

ohms)

Total

harmonic

distortion

half

power

at

1

kHz

0.09%

(8

ohms)

SMPTE

intermodulation

distortion

0.09%

(8

ohms)

Note:

Frequency

response

PHONO

RIAA

standard

curve

+0.8

dB

TUNER,

CD/AUX,

TAPE

1,

TAPE

2/EQ

10:

A270

KHZ;

—3:dB

Total

harmonic

distortion

is

measured

by

the

digital

spectrum

analyzer

(H.P.

3045

system).

Specifications

are

subject

to

change

without

notice

for

further

improvement.

Mi

CONTENTS

SAFETY

PRECAUTION

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

PROTECTION

CIRCUITRY

.........-

BEFORE

REPAIR......-++

+2

sees

HOW

TO

CONNECTION.......-...-:

LOCATION

OF

CONTROLS........

DISASSEMBLY

INSTRUCTIONS

......

BLOCK

DIAGRAM

......++++++:5

Panasonic.

Matsushita

Services

Company

50

Meadowland

Parkway,

Secaucus,

New

Jersey

07094

Panasonic

Hawaii,

Inc.

91-238,

Kauhi

St.

Ewa

Beach

P.O.

Box

774

Honolulu,

Hawaii

96808-0774

Tone

controls

BASS

TREBLE

Loudness

control

(volume

at

~

30

dB)

50

Hz.

+10

dB~

-10

dB

20-KH2,.

4

10:

dB==—10'

dB

Input

sensitivity

50

Hz,

+9

dB

PHONO

0.4

mV

(2.5

mV,

IHF

'66)

Output

voltage

TUNER,

CD/AUX,

TAPE

1,

TAPE

2/EQ

TAPE

1,

TAPE

2/EQ

REC

OUT

150

mV

15

mV

(150

mV,

IHF

'66)

Low

frequency

damping

factor

50

(8

ohms)

S/N

(IHF,

A)

Load

impedance

PHONO

71

dB

(73

dB,

IHF

'66)

MAIN

or

REMOTE

8~16

ohms

TUNER,

CD/AUX,

TAPE

1,

TAPE

2/EQ

MAIN

and

REMOTE

8~16

ohms

75

dB

(94

dB,

IHF

'66)

@

GENERAL

Maximum

input

voltage

;

PHONO

128

mV

(135

mV,

1

kHz)

Power

consumption

360W,

470

VA

Input

impedance

power

supply

|

AC

120V,

60

Hz

PHONO

A?

ionic

Dimensions

(WxHxD)

430

x

oe

x

240

mm

TUNER,

CD/AUX,

TAPE

1,

TAPE

2/EQ

TO:

eee

a

opciones

Weight

7.0

kg

(15.4

Ib.)

Page

roe

tee

2

CIRCUIT

BOARD

AND

WIRING

soe

eee

2

CONNECTION

DIAGRAM....

9~

12

ee

Sa

ee

S

2

SCHEMATIC

DIAGRAM

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

13

™~

16

soe

ee

3

RESISTOR

&

CAPACITORS

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

17

ses

4

REPLACEMENT

PARTS

LIST..............

18

Dee

5,6

EXPLODED

VIEWS...............+.....

19,

20

eee,

Ghana

rs

7,8

Panasonic

Sales

Company,

Division

of

Matsushita

Electric

of

Puerto

Rico,

Inc.

Ave.

65

De

Infanteria,

KM

9.7

Victoria

Industrial

Park

Carolina,

Puerto

Rico

00630

Mi

SAFETY

PRECAUTION

mh

wWhHND

prevent

the

customer

from

being

exposed

to

a

shock

hazard.

e

INSULATION

RESISTANCE

TEST

(This

‘safety

precaution”

is

applied

in

U.S.A.)

.

Before

servicing,

unplug

the

power

cord

to

prevent

an

electric

shock.

.

When

replacing

parts,

use

only

manufacturer’s

recommended

components

for

safety.

.

Check

the

condition

of

the

power

cord.

Replace

if

wear

or

damage

Is

evident.

.

After

servicing,

be

sure

to

restore

the

lead

dress,

insulation

barriers,

insulation

papers,

shields,

etc.

.

Before

returning

the

serviced

equipment

to

the

customer,

be

sure

to

make

the

following

insulation resistance

test

to

1.

Unplug

the

power

cord

and

short

the

two

prongs

of

the

plug

with

a

jumper

wire.

2.

Turn

on

the

power

switch.

3.

Measure

the

resistance

value

with

ohmmeter

between

the

jumpered

AC

plug

and

each

exposed

metal

cabinet

part,

such

as

screwheads

antenna,

control

shafts,

handle

brackets,

etc.

Equipment

with

antenna

terminals

should

read

between

3MQ

and

5.2M2Q

to

all

exposed

parts.

all

exposed

parts.

(Fig.

B)

Note:

Antenna

terminal

Exposed

2

Exposed

metal

Ch

metal

part

|

Ohmmeter

(Fig.

A)

Resistance

=

3M2—5.2MQ

(Fig.

A)

Equipment

without

antenna

terminals

should

read

approximately

infinity

to

Some

exposed

parts

may

be

isolated

from

the

chassis

by

design.

These

will

read

infinity.

(Fig.

B)

Resistance

=

Approx

oo

4.

|f

the

measurement

is

outside

the

specified

limits,

there

is

a

possibility

of

a

shock

hazard.

The

equipment

should

be

repaired

and

rechecked

before

It

is

returned

to

the

customer.

Mi

PROTECTION

CIRCUITRY

The

protection

circuitry

may

have

operated

if

either

of

the

following

conditions

is

noticed:

@

No

sound

is

neard

when

the

power

is

turned

on.

@

Sound

stops

during

a

performance.

The

function

of

this

circuitry

is

to

prevent

circuitry

damage

if,

for

example,

the

positive

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.

Mi

BEFORE

REPAIR

If

this

occurs,

follow

the

procedure

outlines

below:

1.

Turn

off

the

power.

2.

Determine

the

cause

of

the

problem

and

correct

It.

3.

Turn

on

the

power

once

again

after

one

minute.

Note

When

the

protection

circuitry

functions,

the

unit

will

not

operate

unless

the

power

is

first

turned

off

and

then

on

again.

Disconnect

AC

power,

Discharge

both

Power

Supply

Capacitors

C703

and

C704

through

a

102,

5W

resistor

to

ground.

DO

NOT

SHORT-CIRCUIT

DIRECTLY

(witha

screwdriver

blade,

for

instance),

as

this

may

distroy

solid

state

devices.

After

repairs

are

completed,

restore

power

gradually

using

a

variac,

to

avoid

overcurrent.

Current

consumption

at

120V,

60Hz

in

NO

SIGNAL

mode

should

be

250

~

500mA.

e

Accessories

@AC

power

supplycord

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

1

e

Flat

cable

for

remote-control

(SJA172—1)

operation

....

1

(SWKUV96KM)

eBatteries..........

2

(UM—3NEP)

@

Remote-control

@

HOW

TO

CONNECT

Note:

Be

sure

to

use

the

power

cord

included

with

each

unit,

because

some

power

cords

are

polarized

and

some

are

non-

polarized

(plug

shapes

are

different).

foretaTar-xeaccelame)

mer:

le)

(-1-3

Connection

of

AC

power

supply

cords

This

turntable’s

ground

wire

connection

is

not

required

for

this

system.

(Ground

wire

is

not

included.)

Turntable

|

Turntable

(SL-H309U

)

(L)

Household

AC

outlet

AC

po

F

(AC

120V/60

Hz)

wer

Supply

cor

(Included

in

turntable)

-{@)

Tuner

QUTPUT

AC

power

supply

(ST-373)

|

REMOTE

cord

B)

g

CONTROL

(Included

in

tuner)

O

aa

[see]

ria

Tuner

eer

rae

connection

cable

{(pL

A\

To

prevent

overheating

of

the

stereo

amplifier,

only

the

tuner

should

be

placed

on

top

of

it.

AC

power

»

Stereo

connection

supply

cord

AS

cable

(Short)

(Included

ry

in

amplifier)

(R)(L)(R)(L)

Fiat

cable

for

remote-control

Amplifier

. .

ipl

e78!

|

rTAPE)

——

-TAPE2/EQy

[=|

H

7

REC

PLAY

REC

PLAY

PRE

MAIN

|

Amplifier

CD/AUX

OUT

BACK

cp,

OUT

BACK

OUT

IN

:

TAPE1

maria

©

C2

le

TAPE1

we

©

©|6O@

GND

PHONO

TUNER

:

(TUNER)

aa

(R)(L)

(R)(L)(R)(

This

terminal

can

be

:

used

if,

in

the

future,

a

turntable

with

a

ground

wire

is

connected

to

this

amplifier.

L)

{

(R)(L)

(R)

(L)

=

___

Stereo

connection

cable

(Short)

Graphic

Perutagee

Graphic

equalizer

coke

equalizer

(SH-253)

o

oa

|

Flat

cable

for

AC

power

supply

cord

Stereo

connection

cables

remote-control

(option)

(Short)

Tape

deck

m

Tape

deck

(RS-373)

|

LINE

IN.

LINE

OUT

REMOTE

Zz

=

Connection

cable

for

Pe

3

,

Stereo

connection

=

remote-control

|

ee

supply

cor

cable

(option)

R)

(

i

:

(option:

SJP2257T)

(Included

in

cassette

tape

deck)

Compact

Connect

this

cord

to

the

AC

outlet

of

disc

player

the

amplifier

if

the

compact

disc

is

not

(option)

connected

Compact

disc

player

(option)

Mi

LOCATION

OF

CONTROLS

Power

switch

(power)

(volume/balance)

Volume-controls

(volume)

Loudness

switch

(loudness)

Headphones

Tape-monitor

selector/indicator

Balance

controls

jack

(phones)

(tape

2/EQ)

(balance)

Speaker

selectors

(speakers)

Input

selectors/indicators

(input

selector)

Tone

controls

(bass/treble)

CD/tapel

output

Tuner

connector

Playback

TAPE

IL

Playback

a

ah

L-TAPE2

/

EXT

Rec

out

Switched}——-AC

outlets

Main

speaker

terminal

AC

inlet

(+)(—)(—

ine

Lt

«tech

Remote

speaker

terminal!

Rech

Main

in

Ground

Phono

TUNER

CD/

aux

Pre

out

Tape

deck

connector

®

Phono

input

capacitance

is

about

100pF.

fi.

DISASSEM

BLY

INSTRUCTIONS

|

use

No.

How

to

remove

the

main

P.C.B.

How

to

remove

the

front

panel

ATTEN

TOME

Ce.

.

|

Procedure

SOME

CHASSIS

COMPONTS

MAY

HAVE

SHARP

i

(paramos

ane

tO

Meus

(‘O

~

ri0)

.

ene

|

EDGES.

BE

CAREFUL

WHEN

DISASSEMBLING

DO

Pamaveshe

mane

CB

a

1.

Remove

the

top

cabinet.

AND

SERVICING.

.U.D.

2.

Pull

out

the

2

knobs

(@,@).

3.

Remove

the

3

screws

(@

~@

).

4.

Remove

the

2

nuts

(@,

@)

5.

Remove

the

connector.

Removing

the

knob

Connector

(lOpin)

Wind

cellophane

tape

around

the

knob

and

put

it

the

direction

of

the

arrow

as

shown

in

Fig.

1.

Front

panel

Fig.

1

Fig.

2

|

eee

How

to

remove

the

power

amplifier

IC.

How

to

remove

the

P.C.B.

Procedure

3

4

1.

Unsolder

the

power

IC.

1.2

1.

Remove

the

7

screws

(Q@

~

@).

.

a

2.

Remove

the

2

screws

(@,

@).

2.

Remove

the

LED

P.C.B.

:

3.

Remove

the

sub

heat-sink.

4.

Remove

the

2

screws

(@,

@).

LED

PCB

@

When

mounting

the

power

IC,

apply

silicon

thermal

compound

(SZZOL15

or

equivalent)

to

the

rear

of

the

power

'C.,

3.

Remove

the

power

switch

knob.

4.

Remove

the

1

screw

(

@).

Fig.

3

5

Remove

the

power

switch

P.C.B.

a?

6.

Remove

the

1

tab.

Procedure

7.

Remove

the

headphones

P.C.B.

5

Knob

Headphones

PC.B

Power

switch

PC.B

Remove

the

knob

by

pushing

it

Fig.

4

from

behind

the

panel

as

shown

in

Fig.

4.

Hi

BLOCK

DIAGRAM

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2

3

4

5

6

7

8

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CIRCUIT

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DIAGRAM

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(PLAYBACK)

(TAPE)

(TUNER)

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transformer

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guide

of

transistors,

diodes

and

IC's

M50720407SP

|

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TC9163N

TC9177P

SVI3105B

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M5218L

M5238L

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MA165

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R294

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D262

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M50720-408SP

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LNO78328P

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608,610

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11

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switch.

°

5,

S5

:

Loudeness

switch.

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6.S6

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Input

selector,

‘’Tape2/ext”’

switch.

Q257,258

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7.S7

:

Input

selector,

‘‘Tape

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switch.

ey

8.S8

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Input

selector,

‘’‘CD/aux’’

switch.

Q258

9.S9

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selector,

‘“Tuner”’

switch.

yo"

cso2@rs02

10.S10_

:

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selector,

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switch.

cat

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speakers

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position.

has

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12.514

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Remote

speakers

switch

in

‘‘off’’

position.

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switch

in

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position.

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I

8

|

.

7

)

bensos

the

unit

measured

by

the

DC

electronic

circuit

tester

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DRIVE}

(high-impedance)

with

the

chassis

taken

as

standard.

is

x

Therefore,

there

may

exist

some

errors

in

the

voltage

|

i

g

2

values,

depending

on

the

internal

impedance

of

the

Gs

ere

DC

circuit

tester.

Measurement

condition:

Input

selector

—

phono

(no

signal)

Volume

—

Minimum

Loudness

—

off

15;

mm

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Positive

(+B)

voltage

lines

16,

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Negative

(—B)

voltage

lines

17,

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Signal

lines

(L

channel)

18.

Impedance

safety

notice:

|

I

Components

identified

by

A,

mark

have

special,

Lene

ES

RE

f

characteristics

important

for

safety.

When

replacing

any

of

these

components,

use

only

manufacturer’s

specified

parts.

R552

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|

Q255

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111

MUTING

CONTROL

C405

0.01

—

C406

0.01

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R602

470K

(LOUDNESS)

*

Coution!

IC

and

LSI

are

sensitive

to

static

electricity.

Secondary

trouble

can

be

prevented

by

taking

=

care

during

repair.

‘S)

ole

*

Cover

the

parts

boxes

made

of

plastics

with

|

aluminum

foil.

oo

*

Ground

the

soldering

iron.

2

Te

METER

AMP.

CIRCUIT

1C602

BA6I44

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SPEAKERS

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150K

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one

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work

table.

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legs

of

IC

or

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with

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i

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608,610

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3%

3

Cautions:

2p

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>

zy

-

@

The

|1C203

microcomputer

is

to

be

modified

or

S

.

|

7

3

halfway

under

production.

5.7V

.

e

:

[RefNo

|

Old

|New

Gy

0601,603,

607,

5

o

60,603,605

607,603

S

3

IC203

M50720—407SP

|

M50720—408SP

oa

:

@

The

new-type

microcomputer

is

interchangeable

.

a

2

with

the

old

one,

So

the

new

ones

are

shipped

as

replacement

part

for

the

products

already

supplied,

2SD1265

BOF.

sain

ak

os

4

REGULATOR

@

|n

the

circuit

diagram

and

replacement

parts

list

is

described

the

new-type

microcomputer.

—15-

=

Tb

Panasonic SU-373 User manual

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