Kenwood KR-A4010 User manual

AM/FM

STEREO

RECEIVER

KR-A4010

SERVICE

MANUAL

Panel*

Metallic

cabinet

(A20-)

(A01-1746-01)

KENWOOD

ier

sipcness

rnin

Rasxaord

KENWOOD

©

1989-5

PRINTED

IN

JAPAN

B51-3894-00

(O)

3012

Front

glass

(B10-1006-03)

Phone

jack

Knob

(E11-0162-05)

=

(K27-1987-04)

x

2

Lock

terminal

board

*

Bindinng

post

{E20-)

(NO8-0128-35)

FSot*

Phono

jack

(J02-)

x

4

(E13-0446-05)

Slide

switch

*

($31-2136-05)

Phono

jack

(E13-0621-05)

Knob

(K29-3598-04)

X4

Terminal

board

(E20-0823-05)

AC

outlet*

({E03-)

Slide

switch

(S31-2132-05)

(E30-)

Knob

(K29-3597-04)

Knob

(K27-1725-04)

(K29-3632-04)

Slide

switch

*

($31-3010-05)

Power

cord

bushing

(J42-0083-05)

AC

power

cord*

*

Refer

to

parts

list

on

page

38.

KR-A4010

CONTENTS

DISASSEMBLY

FOR

REPAIR

..............::c::seseeeseeeees

3

ADJUSTMENT

....0......ccccescccssesseceeseeeeneeseneenseensees

16

BLOCK

DIAGRAM

............:.:::cccseceeeeeeseeeteeeeeseseneeeenee

5

REGEAGE:

occ.

civcancsccarieceaseseced

caccessce

cdelassssnrostactqeazes

17

CIRCUIT

DESCRIPTION

PABGLEICH

oii

ics

sccesscciecieaceccaacve

ctusecttseeteccdesoeseeseet

18

1.

Description

of

components

............::::cseeeeeseeees

6

ADJUSTMENT/REGLAGE/ABGLEICH

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

19

2.

Microprocessor

uPD7538AC-041

VOLTAGE:

TABLE

oes.

cs.

hcsccscccescbccccneendetediesncestcctes

20

(X11-2650-10

2

1C1)

oo...

ceeeeceeeeeeseeeereeeeeeeseeeenenesenes

7

PC

BORD

(COMPONENT

SIDE

VIEW)

.............06

21

3.

PLL

CX7925B

(X14-2540-10

:

IC2)

.....

ec

eeeeseees

13

PC

BORD

(FOIL

SIDE

VIEW).............ccsscsssrscsersees

25

4.

FM

MPX

AN7470

.(X14-2540-10

:

1C3)

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

14

SCHEMATIC

DIAGRAM

..............:ccsccsessereesersenecsenes

29

5.

STK4171/5

:

Main

amplifier

EXPLODED

VIEW.............::.::ccescccssseeseseeensensneenseennee

37

(X14-2542-71:

1C7)

:

T,

E

type

........::sseseeeeeeees

15

PARTS:

LIST:

ii

silceceses

ees

atieseiiln

asec

rece

aateesa

haste:

38

6.

STK4172/2

:

Main

amplifier

SPECIFICATIONS

............:cssseeeeeeeenenens

BACK

COVER

(X14-2540-XX

:

1C7):

K,

P,

M,

X

type..............006+

15

KR-A4010

DISASSEMBLY

FOR

REPAIR

Befor

repair

work,

take

out

the

case.

1.

Remove

the

five

screws,

then

detach

the

front

panel

(@).

2.

Remove

the

two

screws

then

undo

the

catch

of

the

sub

panel

(@

).

3.

Remove

the

one

screw

(@

).

4.

Undo

the

catch

of

the

PHONES,

then

detach

the

PONES

boad

(X14-)

(B/3)

(@

).

5.

Detach

the

knob

using

a

screwdriver

(@).

6.

Undo

the

catch,

then

the

knob

(@).

7.

Remove

the

one

screw

(@)

and

the

one

hook

(@),

then

detach

the

PCB.

8.

Remove

the

one

screw

(@),

then

detach

the

power

switch.

9.

Remove

the

six

screws

(@)

and

the

twelve

screws

(@

),

then

detach

the

display

board

(X11-)

(A/2).

KR-A4010

DISASSEMBLY

FOR

REPAIR

When

repairing

or

checking

the

main

PC

board

and

power

supply

refer

to

the

following

steps.

1.

Remove

the

five

screws

(@).

2.

Remove

the

six

screws

(Q

).

3.

In

this

way,

the

FM

terminal

mold

will

hit

against

the

chassis.

To

avoid

this,

lift

up

the

main

body

putting

aside

the

rear

panel

in

the

direction

of

an

arrow

(@)(@).

KR-A4010

BLOCK

DIAGRAM

Olt-OvSZ-blLx

|

01-0692-11X

|

Ol-ObG2-b

Lx

;

|

(6)

Avid

|

SS3NQNNO1

|

IdVL

S3NOHd

|

.

|

x)

|

ae

0

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€eS

|

a@

pence

aesa

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amram

acres

O)

O3GIA

A

|

LYA

|

©)

4yO1L9373S

VY

i

SZ

O)

dd

|

vat

IS

o)

SY3nNVadSs

291

2

|

[or

JO

oon

(ATNO

3dVL

169)

AV138

Ly

|

vol

Bens

es

ee

teas

ects

Te

Pes

toe

oN

ne

NS,

Leet

Ay

Ol-OvS2

—

1x

Wd

3d‘71

Z9l

Ss

ee

an

£91

Lol

90

p~lod

KR-A4010

CIRCUIT

DESCRIPTION

1.

Description

of

Components

CONTROL

UNIT

(X11-265X-XX)

0-10:

K,P

0-21:M

2-71:X,T,E

Part

No.

Use/Function

Operation/Condition/Compatibility

IC1

pPD7538AC-041

Micro

computer

IC2

PST529C

Reset

Q2

2SA733

(A)

(Q,P)

Cannel

space

selection

ON

:

9kHz,

50kHz

OFF

:

10kHz,

100kHz

2SA933S

(Q,R)

Q3

2SA733

(A)

(Q,P)

Indication

driver

TUNED

display

I

2SA933

(Q,R)

Q4

2SA733

(A)

(Q,P)

Indication

driver

STEREO

display

2SA933

(Q,R)

Q5

2SC945

(A)

(Q,P)

LED

driver

For

PHONO

2SC1740S

(Q,R)

RECEIVER

UNIT

(X14-254X-XX)

0-10:

K,P

0-21:M

0-71:X

2-71:T,E

Part

No.

Use/Function

Operation/Condition/Compatibility

|

1C1

LA1265

FM/AM

system

IC

FM

IF

amplifier

detection

and

control

:

AM

mixing,

IF

amplifier

and

derection.

IC2

CX-79258

PLL

IC

for

frequency

synthesizer

PLL

for

electronic

tuning.

IC3

AN7470

MPX

IC

MPX

demodulator.

IC4

NJM4558D-A

Equalizer

amplifier

Equalizer

amplifier

for

PHONO

(MM).

M5218P-A

IC5

LC7820

Input

selector

SW

Analog

switch

for

input

selector

switches.

C7

STK4172/2

Main

amplifier

Main

amplifier

(2ch).

(K,P,M,X

type)

1C7

STK4171/5

Main

amplifier

Main

amplifier

(2ch).

(T,E

type)

IC8

PC7812HF

Constant

voltage

power

supply

3-pin

regulator

for

the

+12V

constant

voltage

supply.

Qi

2SK241

RF

amplifier

High-frequency

amplifier.

(K,P,M,X

type)

Qi

2SK73

RF

amplifier

High-frequency

amplifier.

(T,E

type)

Q2

2SC1923

(O)

Mixing

Frequency

converter.

Q3

2SC1923

(R,O)

OSC

Local

oscillator.

Q4

2SC1923

(R,O}

OSC

buffer

OSC

OUT

(oscillator

output)

for

synthesizer.

Q5

2SK161

(Y,GR)

OSC

buffer

For

local

oscillator

input

to

mixer.

(T,E

type)

Q6

2SC1923

(R,O)

FM

IF

amplifier

10.7MHz

amplifier.

Q7

2SC1845

(F,E)

LPF

Low

pass

filter

for

PLL.

Q8

2SC1740S

(Q,R)

LPF

Low

pass

filter

for

PLL.

2SC945

(A}

(Q,P}

ag

25C1740S

(Q,R)

Buffer

for

L6

(T,E

type)

2SC945

(A)

(Q,P}

Q10,11

25C1740S

(Q,R)

Emphasis

switch

ON

for

75s,

OFF

for

501s.

(

M

type)

2SC945

(A)

(O,P)

Q12

DTC124ES

FM

+

B

control

Q13

DTA114ES

FM

+

B

control

Q14

|

DTC124ES

AM

+

B

control

Q15

DTA114ES

AM

+

B

control

Q17,18

25C2878

(B)

Muting

TAPE

REC

OUT

pop

noise

prevention

during

switching

selector

switch.

Q19

2SA933S

(Q,R)

Muting

control

Main

amplifier

pop

noise

prevention

during

switching

selector

switch.

2SA733

(A}

(Q,R)

Q20,21

2S$C2878

(B)

Muting

Main

amplifier

pop

noise

prevention

during

switching

selector

switch.

Q22

2SA933S

(Q,R)

Muting

control

2SA733

{A}

(Q,P)

Q25

2SA933S

(Q,R)

Muting

Main

amplifier

pop

noise

prevention

during

switching

power

switch.

2SA733

{A}

(Q,P)

Q26,27

2SC1845

(F,E)

Protection

Q28

2SA945

(L,K)

Regulator

power

supply

Output

transistor

for

24V

control

voltage

supply.

Q29

2SA933S

(Q,R}

Error

amplifier

-12V

error

amplifier.

2SA733

(A)

(Q,P)

Q30

2SA945

(L,K)

Constant

voltage

circuit

-12V

Q32

2SC2003(L,K)

Regulator

power

supply

Output

transistor

tor

5V

constant

voltage

supply.

CIRCUIT

DESCRIPTION

2.

Microprocessor

1.

PD7538AC-041

(X11-2650-10

:

IC1)

Terminal

connection

diagram

&

key

matrix

connection

KR-A4010

Lil

|

Reset

ves

2

4!

|

|-=e

cli

POO/INTO

33

Ca

|

vest

PO3/S!

(vem)

AUTO

STEREO

P53

P30

or

PHONO/MAIN

2

P52

P31

>

SUB

<7

PSI

P32

Pe

(1)

(>)

MUTE

P50

P33

od

ap

-

ee?

bae

~

©

|

SEG

P40

CX7925S

!

j

A

CLK

3

P2I7POUT

P42

=

9

coveann

«<2

Pi03

P43

=

a

>h

pai

Tuner

«<4

pioz

P80

i!

i

5

i5

28

VIDEO/TEST

<=

PIO!

Pal

fo

|

TAPE/Bilingual

=

P100

P82

=

2

ae

|

To

$0

8

PUB

(ee

P83

25

3

|

Grip

la

>t

Video

(co)

CE

Pil2

P30

4

DATA

=

PI

P9l

24

5.

BUSY

PIO

P92

6

Voo

P93

POWER

LiL

Block

diagram

POO/INTO

ZERO-

CROSS

DETECTOR

CLOCK

CONTROL

TIMER/EVENT

COUNTER

INTERRUPT

CONTROL

P80

PO1/SCK

PO2/SO

SERIAL

INTERFACE

PROGRAM

MEMORY

INSTRUCTION

4096x8

BITS

DECODER

SYSTEM

CLOCK

GENERATOR

STANDBY

CONTROL

CLI

CcL2

Vop

Vss_

«RESET

GENERAL

REGISTERS

STACK

POINTER(8)

DATA

MEMORY

160x4

BITS

Bond Bond

fo)

|

PO3/S1

-_

Band

2

"8

Vere

VioAD

|

lee

POO-PO3

PORT2

LATCH

BUFFER

P2I-P23

PTOUT/P2!

LATCH

BUFFER

PORT4

K_

LATCH

K

4

pao-pa3

BUFFER

PORTS

LATCH

BUFFER

PORTS

LATCH

BUFFER

PORTS

LATCH

BUFFER

|

4)

P90-P93

PORTIO

LATCH

BUFFER

K"4_)

P100-P103

PORTI1

LATCH

BUFFER

K

4)

PO-PH3

KR-A4010

CIRCUIT

DESCRIPTION

Function

of

the

diode

switch

1.

Models

for

each

designated

area

and

function

setting

switches

Model

for

desig-

Set

switch

Receiving

Channel

Reference

Middle

nated

area

Band

3|/Band

2/Band

1

frequency

range

spacing

frequency

87.5

~

108

MHz

100

kHz

50

kHz

10.7

MHz

530

~

1610

MHz

10

kHz

10

kHz

450

kHz

4

87.5

~

108

MHz

50

kHz

50

kHz

10.7

MHz

531

~

1602

kHz

9

kHz

9

kHz

450

kHz

163

~

281

kHz

1

kHz

1

kHz

450

kHz

0 0

K

type

or

E

type

(without

LW)

Band

3

H

Overseas

L

Domestic

(Japan)

Band

2

H

FMch

space

50

kHz

&

AMch

space

9

kHz

L

FMch

space

100

kHz

&

AMch

space

10

kHz

Band

1

H

Without

auto

tuning

function

only

for

LW

broadcast

Band

0

H

With

LW:

Indication

(FM,

MW,

LW)

L

Without

LW:

Indication

(FM,

AM)

LW

key

is

not

accepted.

2.

Stop

frequency

select

switch

for

auto

tuning

in

LW

@

Setting

of

this

switch

can

be

changed

without

reception

resetting

(unplugging/plugging

the

AC

cord.)

This

switch

is

used

to

set

the

frequency

which

intakes

the

SD

signal

in

LW

band

reception.

For

both

manual

and

auto

tuning,

the

tuning

frequency

is

changed

up

or

9N-+

2

|Frequency/Channel|Reference|

Middle

Stop

/9N

range

spacing

|

frequency

|

frequency

down

in

1

kHz

step,

however,

in

auto

tuning

mode,

the

153

~

155,

164

.....

ae

1

281

kHz

|

1

KHz

1

kHz

450

kHz

|

525587

KH

receiving

frequency

stops

at

the

following

frequency

=

:

163

~

153,

162...

selected

by

this

switch.

|

o

|

281

kHz

450

kHz

|

950979

KHe

3.

Auto

tuning

4.

Others

Auto

tuning

Auto

tuning

function

Auto/Mono

KEY

Function

Preset

16

Preset

20

1

|

Not

available

Mono/Stereo

function

only

0

Available

This

key

is

also

used

as

the

Auto/Man-

ual

tuning

mode

key

Set

switch

6)

1

KR-A4010

CIRCUIT

DESCRIPTION

Port

allocation

Function

Key

return

signal

input

Key

return

signal

input

Key

return

signal

input

Key

return

signal

input

PLL

IC

(CX7925B)

Function

SW

(LC7820)

Data

output

PLL

IC

(CX7925B)

LAT

output

PLL

IC

(CX7925B)

CLK

output

oO}

w

FL

display

segment

output:

nN

Tyr}

rT

{Tz}

TT

TTT

a

T

Function

SW

(LC7820)

Key

strobe

signal

output.

Key

strobe

signal

output,

FL

display

segment

output:

Key

strobe

signal

output.

FL

display

segment

output:

Key

strobe

signal

output.

FL

display

segment

output:

-1O}W!/N

xrjxrjrl/t

Key

strobe

signal

output,

Key

strobe

signal

output.

FL

display

segment

output:

FL

display

segment

output:

(0)

|

oOo

|

H

i)

pa

ef

Key

strobe

signal

output,

FL

display

segment

output:

Key

strobe

signal

output,

FL

display

segment

output:

TFIO;T/MDIQl

o;T]o

Key

strobe

signal

output

oO

FL

display

segment

output

FL

display

digit

control

pin:

GRID

1

FL

display

digit

control

pin:

GRID

2

FL

display

digit

control

pin:

GRID

3

<

—-}O!}a

NIN

w

ames)

oO

bf

t

T

lox

Ke)

x

}Tl/TyryTt

.|

Power

supply

input

(5V)

FL

display

digit

control

pin:

GRID

4

FL

display

digit

control

pin:

GRID

5

FL

display

digit

control

pin:

GRID

6

Input

port:

TV

mode

“Bilingual”

(H)

Output

port:

Receiver

selector

“TAPE”

Input

port:

TEST

(H)

Output

port:

Receiver

selector

“VIDEO”

Receiver

selector

“TUNER”

Receiver

design:

Receiver

selector

“CD”

System

component

design:

Band

data

output

(UHF:

H)

Serial

signal

BUSY

Serial

signal

DATA

Back

up

detection

Station

detection

for

auto

tuning

mode

OWN}

-|O]

w

=

Muting

signal

TV

SUB

Receiver

design:

Receiver

selector

“PHONO”

System

component

design:

TV

MAIN

Stereo

(L)

MONO/SST

key

to

control

Mono

(H)

Reset

signal

Clock

Power

supply

for

FL

display

pre-driver

Power

supply

for

FL

display

driver

(—

30V)

KR-A4010

10

CIRCUIT

DESCRIPTION

Key

matrix

layout

POO

(41)

PO1

(40)

PO2

(39)

PO3

(38)

P30

(37)

UP

DOWN

AUTO

MONO

Preset

P31

(36)

Scan

P32

(35)

——_--+

P33

(34)

|

P40

(33)

Sound

multiplex

P42

(31)

i

cD

*

Auto

tuning

P41

(32)

*16

Preset

20

Preset

P43

(30)

Receiver

@

Values

in

brackets

(

*

Band

1

*Band

3

*Band

2

)

shows

the

number

of

P80

(29)

microcomputer.

@

items

with

an

asterisk

(")

shows

the

diode

switch.

Others

are

momentary

switches.

@

LW

(9N+2/9N)

is

the

slide

switch

on

the

rear

panel.

@

Key-intake

is

active

high.

Tuner

function

1.

Manual

tuning

Each

time

the

UP/DOWN

key

is

pressed,

the

tuning

frequency

is

varied

one

step

higher

or

lower.

When

this

key

is

kept

pressed

for

more

than

0.5

seconds,

the

frequency

is

changed

up

or

down

at

approx.

128

msec/step

(approx.

224

msec/step

for

TV

reception)

until

the

key

is

released.

.

Auto

tuning

When

the

AUTO/MONDO

switch

is

set

to

AUTO,

press-

ing

the

UP/DOWN

key

starts

auto

tuning.

The

tuning

frequency

is

changed

up

or

down

at

approx.

128

msec/step

(approx.

224

msec/step

for

TV

reception)

until

the

high-level

signal

is

input

to

the

SD

pin.

When

the

high-level

signal

is

input,

auto

tuning

operation

stops.

.

Preset

memory

Up

to

16

or

20

frequencies

(the

maximum

number

of

preset

stations

is

set

by

the

diode

switch)

can

be

preset

randgmly

for

FM,

MW

(AM)

and

LW

(TV)

stations.

a)

How

to

preset

When

the

MEMORY

key

is

pressed,

the

MEMORY”

indicator

lights

and

the

unit

is

set

to

the

write-enable

Status.

Writing

to

memory

is

possible

for

approx.

5

seconds

after

the

MEMORY

key

is

pressed.

During

this

time,

pressing

any

of

the

numeric

key

(1

—

10)

will

write

the

currently-received

frequency

into

memory

corre-

sponding

to

the

key

pressed.

b)

How

to

recail

When

the

tuner

functions,

pressing

any

of

the

preset

keys

will

recall

the

stored

contents

corresponding

to

the

key

pressed.

.

Preset

scan

When

the

PRESET

SCAN

key

is

pressed,

the

SD

goes

high

level.

A

preset

channel

is

received

for

5

Test

frequency

530

|

630

|

@

Test

mode

set-up:

:

FM

87.5

89.1

AM

ee

1440/1602]

153

Set

the

test

(P15)

to

high

level,

and

invert

it

to

low

level

after

turning

the

power

ON.

(The

entire!

FL

display

will

light

except

for

MEMORY.)

seconds,

then

the

receiving

frequency

is

changed

to

the

channel.

When

the

SD

is

low

level,

the

receiving

channel

is

changed

to

the

channel

after

one

second.

a)

Key

processing

during

scanning

@

Preset

key:

Stops

the

scanning

operation

and

receives

the

frequency

of

the

designated

preset

channel.

@

UP/DOWN

key:

Stops

the

scanning

operation

and

processes

the

UP/DOWN

function.

Kenwood KR-A4010 User manual

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