Akai GX4000D Guía de solución de problemas

Otros manuales para GX4000D

1

Este manual sirve para los siguientes modelos

1

Tabla de contenidos

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SERVICE

MANUAL

PARTS

LIST

nooo.

ADO

BESS

ALSO

APPLICABLE

TO

BLACK

PANEL

MODEL

AKAI

STEREO

TAPE

DECK

voor.

GX-4000D/DB

ALSO

APPLICABLE

TO

BLACK

PANEL

MODEL

SECTION

1

SERVICE

MANUAL

........-.-----0

252

e

eee

3

SECTION

2

PARTS

LIST

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

2-002

s

ceteris

33

SECTION

3

SCHEMATIC

DIAGRAM

......--.----+--+--5-

59

II.

II.

VIE.

VUE.

SECTION

1

SERVICE

MANUAL

TABLE

OF

CONTENTS

TECHNICAL:

DATA

33:57.

220

bel

cao

aaa

ee

ae

Fea

4

Is,

“MODEL

‘GX-4Q00D

5.

i2s.0

Bon

ee

fp

avetain

ates

we

yet

4

2.

‘MODEL

-GX-4000DB

-.

».

025600

4

ecg

ets

aan

ee

adiae

gy

Hoe

0s

5

DISMANTLING

OF

UNIT...

0...

ee

eens

6

CONTROLS:

(feet

fn

susie

aiden

geal

a

inet

tare

wh

4

ae

eae

ks

8

PRINCIPAL

PARTS

LOCATION

........

0.0.0.0.

0

cee

eee

eens

10

MECHANISM

ADJUSTMENT

..........

0.000.

c

eee

ee

eee

11

1.

PINCH

ROLLER

PRESSURE

MEASUREMENT

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

il

2.

REEL

TABLE

BLOCK

ADJUSTMENT

..........

00000000

eeu

1}

3.

DRIVE

BELT

POSITION

ADJUSTMENT

..............-.0005-

13

4.

FLYWHEEL

LOOSE

PLAY

ADJUSTMENT

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

0.00000

13

5.

AUTOMATIC

SHUT-OFF

OPERATING

POINT

ADJUSTMENT

......

13

HEAD

ADJUSTMENT

............0

0c

c

eee

cece

eee

eens

14

1.

HEAD

HEIGHT

ADJUSTMENT

....... 0.0.0.0

0.

000

cee

eee

14

2.

HEAD

AZIMUTH

ALIGNMENT

ADJUSTMENT

.............00.

I4

3.

HEAD

ANGLE

ALIGNMENT

ADJUSTMENT

...........-..00-.

15

AMPLIFIER

ADJUSTMENT

.........

00.00.00

ce

cece

eee eee

es

16

Ts,

MODEL

GX4000D

12865

oss

ig

s

song

ah

Ee

peal

Se

eS

2s

16

2,

“MODEL:.GX-4000DB:..

022-3

fa

ade

ee

ata

alee

ees

2

aes

18

DC

RESISTANCE

OF

VARIOUS

COILS

...........

00-0000

002

eee

20

CLASSIFICATION

OF

VARIOUS

P.C

BOARDS

.........2...-.0-45

20

1.

P.C

BOARD

TITLE

AND

IDENTIFICATION

NUMBER

...........

20

2.

MODEL

GX-4000D

COMPOSITION

OF

VARIOUS

P.C

BOARDS.....

ak

3.

MODEL

GX-4000DB

COMPOSITION

OF

VARIOUS

P.C

BOARDS

....

26

For

basic

adjustments.

measuring

methods.

and

operating

principles,

refer

to

GENERAL

TECHNICAL

MANUAL.

ve

1.

TECHNICAL

DATA

1.

MODEL

GX-4000D

TRACK

SYSTEM

4

track,

2

channel

stereo/monaural

system

REEL

CAPACITY

Up

to

7”

reel

TAPE

SPEED

wow

&

FLUTTER

7-1/2

and

3-3/4

ips

Less

than

0.08%

WRMS

FREQUENCY

RESPONSE

DISTORTION

(1,000

Hz

“0”

VU)

30

to

24,000

Hz

+3

dB

at

7-1/2

ips

30

to

16,000

Hz

+3

dB

at

3-3/4

ips

SIGNAL

TO

NOISE

RATIO

Less

than

1.0%

at

7-1/2

ips

Better

than

60

dB

(measured

via

tape

with

peak

recording

level)

ERASE

RATIO

Better

than

70

dB

BIAS

FREQUENCY

100

kHz

HEADS

(3):

One

GX

Recording

head,

one

GX

Playback

head,

one

Erase

head

MOTOR

(1):

4-pole

induction

motor

FF

&

REWIND

TIME

200

sec

using

1,200

ft.

tape

OUTPUT

JACKS

Line

(2):

0.775V

(“0"

VU)

Required

load

impedance:

more

than

50

kohms

Phone

(1):

100

mV/8

ohms

INPUT

JACKS

Microphone

(2):

0.25

mV

Required

microphone

impedance:

600

ohms

Line

(2):

70

mV

DIN

JACK

SEMICONDUCTORS

DIMENSIONS

WEIGHT

POWER

REQUIREMENTS

Input:

2

mV/10

kohms,

Output:

0.3V

Transistors:

24.

Diodes:

13,

FETs:

2,

IC:

1

440(W)

x

315(H)

x

230(D)

mm

(17.3

x

12.4

x

9.1")

13.2

kg

(29.1

Ibs)

100V,

50/60

Hz

for

Japan

120V,

60

Hz

for

Canada

&

U.S.A.

220/240V,

50 Hz

for

European

Countries

&

Australia

110/120/220/240V

(Switchable),

50/60

Hz

for

the

other

Countries

a

2.

MODEL

GX-4000DB

TRACK

SYSTEM

REEL

CAPACITY

4

track,

2

channel

stereo/monaural

system

Up

to

7”

reet

TAPE

SPEED

BI

7-1/2

and

3-3/4

ips

WOW

&

FLUTTER

Less than

0.08%

WRMS

FREQUENCY

RESPONSE

|

30

to

24,000

Hz

+3

GB

at

7-1/2

ips

30

to

16,000

Hz

+3

dB

at

3-3/4

ips

DISTORTION

(1,000

Hz

“0”

VU)

Less

than

1.0%

at

7-1/2

ips

SIGNAL

TO

NOISE

RATIO

Better

than

60

dB

(measured

via

tape

with

peak

recording

level)

__|

Dolby

Switch

ON:

Improves

up

to

10

dB

above

5

kHz

ERASE

RATIO

Better

than

70

dB

BIAS

FREQUENCY

r

100

kHz

HEADS

(3):

One

GX

Recording

head,

one

GX

Playback

head

one

Erase

head

MOTOR

+

(1):

4-pole

induction

motor

FF

&

REWIND

TIME

200

sec

using

1,200

ft

tape

OUTPUT

JACKS

Line

(2):

580

mV

“0”

VU)

Required

load

impedance:

more

than

100

kohms

Phone

(1):

100

mV/8

ohms

INPUT

JACKS

DIN

JACKS

SEMICONDUCTORS

DIMENSION

WEIGHT’

POWER

REQUIREMENT

Microphone

(2):

0.25

mV

Required

microphone

impedance:

600

ohms

Line

(2):

70

mV

Input:

2

mV/10

kohms

Output:

0.3V

Transistors:

21,

Diodes:

21,

FETs:

2,

ICs:

5

440(W)

x

315(H)

x

230(D)

mm

(17.3

x

12.4

x

9.4")

13.2

kg

(29.1

Ibs)

120V,

60

Hz

for

Canada

&

U.S.A.

220/240V,

50

Hz

for

European

Countries

&

Australia

e

‘:

pels

é

f

For

improvement

purposes.

specifications

and

design

are

subject

to

change

without

notice.

110/120/220/240V

(Switchable),

50/60

Hz

for

the

other

Countries

*

For

improvement

purposes.

specifications

and

design

are

subject

to

change

without

notice.

*

“Dolby”

and

the

Double

D

symbol

are

trademarks

of

Dolby

Laboratories.

(Manufactured

under

license

from

Dolby

Laboratories.)

ll.

DISMANTLING

OF

UNIT

In

case

of

trouble,

etc.

necessitating

dismantling,

please

dismantle

in

the

order

shown

in

the

photographs.

Reassemble

in

reverse

order.

SiDE

BCARD

SCREWS:

SCREWS

PiNCH

ROLLER

CAl

BACK

BCAA

UPCER

COVER

~d

Hl.

CONTROLS

@eeeeeeeees

Seaeeoeseeoense

eevseeseosr

eeeccece

st

Oh

OUR

NS

PINCH

ROLLER

CAPSTAN

REEL

RETAINER

(Left)

SUPPLY

REEL

TABLE

HEAD

COVER

TAPE

GUIDE

INDEX

COUNTER

&

RESET

BUTTON

TRACK

SELECTOR

VU

METERS

(Left

&

Right)

OUTPUT

VOLUME

.

HEADPHONE

JACK

RECORDING

INDICATOR

LAMP

.

RECORDING

SAFETY

BUTTON

.

AUTOMATIC

STOP

LEVER

REEL

RETAINER

(Right)

.

TAKE-UP

REEL

TABLE

.

RECORDING/PLAYBACK

LEVER

18,

19.

20,

21.

22.

23.

24,

25.

26.

27.

28.

29.

30.

31.

32.

33.

34,

Fig.

1

Controls

FAST

FORWARD/REWIND

LEVER

PAUSE

LEVER

START

BUTTON

POWER

MONITOR

SELECTOR

SWITCH

(Tape

&

Source)

$.0.S.

(Sound-On-Sound)

BUTTON

MICROPHONE

JACKS

(Left

&

Right)

MICROPHONE

RECORDING

LEVEL

CONTROLS

LINE

RECORDING

LEVEL

CONTROLS

TAPE

SELECTOR

SWITCH

EQUALIZER

SWITCH

DIN

JACK

LINE

OUTPUT

JACKS

(Left

&

Right)

LINE

INPUT

JACKS

(Left

&

Right)

DOLBY

N.R.

INDICATOR

LAMP

$.0.S.

SWITCH/LINE

RECORDING

LEVEL

CONTROLS

DOLBY

N.R.

SWITCH

IV.

PRINCIPAL

PARTS

LOCATION

V.

MECHANISM

ADJUSTMENT

TENTION

SWITCH

Sw902

PAUSE LEVER

3

"

:

9

th

START

SUTTON

TRACK

SELECTOR

; :

7

ats

y

swi

:

or

ae

POWER

SWITCH

Swi

MEADPHON

: :

ao

By

:

HEADPHONE

VACK

eS

Pe

:

a

H

a

me

&

é

Le,

a

oe

4

ma

MACK

Bree

Fig.

4

Pinch

Roller

Pressure

Measurement

MONITOR

Sw

-1

OUTPUT

VRO

$08

$w4.2

—_—

MIS

REC

LEVEL

VR?

1

INE

REC

LEVEL

vee

£9

Sw4-3

Lo

rape

SELECTOR

Swa-4

Fig.

2

Front

View

(GX-4000D)

1.

PINCH

ROLLER

PRESSURE

MEASUREMENT

(Refer

to

Fig.

4)

!

Set the

recorder

in

the

PLAY

Mode.

Pull

the

pinch

‘

roller

1~2

mm

away

from

the

capstan

with

the

spring

¢90!

3

gauge

as

shown

in

Fig.

4.

Slowly

release

and

take

the

spring

gauge

reading

when

the

pinch

roller

touches

the

capstan

and

begins

to

rotate.

The

specified

pinch

roller

pressure

is

1

150~1

200g.

(Tape

speed:

7-1/2

ips)

POWER

TRINSFORMER

Te0r

tee

gee

MoroR

M901

2.

REEL

TABLE

BLOCK

ADJUSTMENT

(Refer

to

Figs.

5,

6)

*

Necessary

points

when

measuring

the

tension

Wind

the

tape

onto

a

5”

empty

reel

until

there

is

a

diameter

of

60

mm

of

tape.

(See

Fig.

5).

Make

the

end

of

the

tape

into

a

loop

and

put

onto

the

spring

gauge.

:

*

Lug

E

gh

cult

ddieo

ee

oe

RINE_QUTPUT.

JACKS

LINE

INPUT

JACKS

DIN

JACK

Fig.

3

Rear

View

(GX-000D)

|

i

A.

SUPPLY

REEL

TABLE

BLOCK

ADJUSTMENT

1)

RWD

Tension

Adjustment

A

spring

gauge

reading

of

400~500g

in

the

RWD

Mode.

To

adjust,

increase

or

decrease

the

number

of

(1)

washers.

2)

PLAY

Mode

Back

Tension

Adjustment

A

spring

gauge

reading

of

100~120g

in

PLAY

Mode.

To

adjust,

increase

or

decrease

the

number

of

(2)

washers.

3)

FF

Free

Tension

Adjustment

A

spring

gauge

reading

of

15~20g

in

the

FF

Mode.

To

adjust.

move

the

position

of

puiley

(3)

back-

wards

and

forwards.

B.

TAKE-UP

REEL

TABLE

BLOCK

ADJUSTMENT

1)

FF

Tension

Adjustment

A

spring

gauge

reading

of

400~500g

in

the

FF

Mode.

To

adjust.

increase

or

decrease

the

number

of

(1)

washers.

2)

PLAY

Tension

Adjustment

A

spring

gauge

reading

of

150~180g

in

the

PLAY

Mode.

To

adjust,

increase

or

decrease

the

number

of

(2)

washers.

3)

RWD

Free

Tension

Adjustment

A

spring

gauge

reading

of

15~20g

in

the

RWD

Mode.

To

adjust.

move

the

position

of

pulley

(3)

back-

wards

and

forwards.

SUPPLY

REEL

TAGE

%

eLcock

TAKE-UP

REEL

TAGLE

O8LOCK

Fig.

6

LUTLIL

EAU

ATLLILLLUT

DIMEN

LAT

OLY

LECT

ULLLL

L

RULLILEAS

AOJUSTMENT

WASHER

Fig.

7

3.

DRIVE

BELT

POSITION

ADJUSTMENT

(Refer

to

Fig.

7)

Adjust

position

of

drive

belt

so

that

it

comes

to

the

center

of

the

motor

pulley

by

inserting

a

washer

(or

washers)

between

the

motor

prop

and

mechanism

chassis

as

shown

in

Fig.

12.

4.

FLYWHEEL

LOOSE

PLAY

ADJUSTMENT

(Refer

to

Fig.

8)

With

a

minus

screw

driver,

turn

bearing

to

left

and

right

and

adjust

so

that

when

the

flywheel

is

moved

as

indicated

by

the

arrow

mark

in

the

figure,

the

gap

between

the

steel

ball

and

flywheel

supporting

plate

is

0.3

mm

as

shown

in

Fig.

8.

Fix

at

this

position

with

nut.

MICRO

SWITCH

ADJUST

WITH

DRIVER

LELELLLSUS

TSO

LMLE

ACAD

LALIT

S

MECHANISM

CHASSIS

Fig.

8

A

LEVER

SHAFT———e{),

ot

5.

AUTOMATIC

SHUT-OFF

OPERATING

POINT

ADJUSTMENT

(Refer

to

Fig.

9)

Loosen

screws

(a)

and

(b)

and

adjust

installed

posi-

tion

of

Micro

Switch

so

that

when

AS

Lever

is

lowered

as

a

result

of

the

Power

Switch

being

set

to

SHUT-OFF

position,

the

gap

between

AS

Lever

is

about

5

mm.

i

se

eS

SS

Se

Vi.

HEAD

ADJUSTMENT

A

EL

REC

ANGLE

PS

ANGLE

tea)

a)

Ga

3.

HEAD

ANGLE

ALIGNMENT

if

|

|

ADJUSTMENT

(Refer

to

Fig.

10)

1)

Playback

Head

a.

Connect

a

High

Sensitivity

AC

Voltmeter

to

the

left

and

right

channel

Output

Terminals

of

the

tape

deck.

b.

Set

the

Track

Selector

to

STEREO

and

set

the

machine

to

7-1/2

ips

tape

speed.

c.

Playback

an

8,000Hz

3-3/4

ips

alignment

adjustment

test

tape.

d.

Loosen

screw

(j).

Adjust

PB

angle

in

the

direc-

tion

of

the

arrow

and

change

the

angle

of

the

head-to-tape

contact.

Fix

the

PB

head

at

a

position

where

the

output

level

is

not

effected

by

an

additional

tension

to

the

supply

reel.

TAPE

(e.g.

slightly

touching

the

supply

reel).

2)

Recording

Head

a.

Connect

an

Audio

Frequency

Oscillator

to

the

z

line

input

through

an

Attenuator,

and

connect

es

200

"pe-20ir

4-240

(=

a

High

Sensitivity

AC

Voltmeter

to

the

line

output.

Then

load

a

blank

test

tape.

Fig.

10

b.

Set

the

Monitor

Switch

to

SOURCE

and

supply

ig.

a

16,000Hz

sine

wave

signal.

Adjust

the

Attenuator

or

the

Line

Recording

Level

Con-

trols

to

obtain

a

—20

dBm

High

Sensitivity

AC

Voltmeter

indication.

c.

Reset

Monitor

Switch

to

TAPE

and

set

deck

to

recording

mode.

1,

HEAD

HEIGHT

ADJUSTMENT

2.

HEAD

AZIMUTH

ALIGNMENT

d.

Loosen

screw

(i).

Adjust

REC

angle

in

the

(Refer

to

Fig.

10)

ADJUSTMENT

(Refer

to

Fig.

10)

direction

of

the

arrow

and

change

the

angle

of

1)

Erase

Head

1)

Playback

Head

the

head-to

tape

contact.

Loosen

screws

(a)

and

(b)

shown

in

Fig.

10

and

adjust

erase

head

height.

Tighten

screws

at

posi-

tion

at

which

the

upper

edge

of

the

tape

is

0.1

mm

lower

than

the

upper

edge

of

the

left

channel

head

core

of

the

erase

head.

2)

Recording

Head

Adjust

head

height

adjustment

screws

(c)

and

(d)

shown

in

Fig.

10

so

that

the

upper

edge

of

the

tape

and

the

upper

edge

of

left

channel

head

core

of

the

recording

head

are

the

same

height.

3)

Playback

Head

Adjust

head

height

adjustment

screws

(f)

and

(g)

shown

in

Fig.

10

so

that

the

upper

edge

of

the

tape

and

the

upper

edge

of

left

channel

head

core

of

the

playback

head

are

the

same

height.

a.

Connect

a

High

Sensitivity

AC

Voltmeter

to

the

left

and

right

channel

Output

Terminals

of

the

tape

deck.

b.

Set

the

Track

Selector

to

STEREO

and

set

the

machine

to

7-1/2

ips

tape

speed.

c.

Playback

an

8,000Hz

3-3/4

ips

alignment

adjustment

test

tape.

d.

Adjust

adjustment

screw

(h)

to

obtain

max-

imum

High

Sensitivity

AC

Voltmeter

indication

on

both

channels.

2)

Recording

Head

a.

Connect

an

Audio

Frequency

Oscillator

to

the

line

input

through

an

Attenuator,

and

connect

a

High

Sensitivity

AC

Voltmeter

to

the

line

output.

Then

load

a

blank

test

tape.

b.

Set

the

Monitor

Switch

to

SOURCE

and

supply

a

16,000Hz

sine

wave

signal.

Adjust

the

Attenuator

or

the

Line

Recording

Leve!

Con-

trols

to

obtain

a

—20

dBm

High

Sensitivity

AC

Voltmeter

indication.

c.

Reset

Monitor

Switch

to

TAPE

and

set

deck

to

recording

mode.

d.

Adjust

adjustment

screw

(e)

to

obtain

max-

imum

High

Sensitivity

AC

Voltmeter

indication

on

both

channels.

Fix

the

REC

head

at

a

position

where

the

out-

put

level

is

not

effected

an

additional

tension

to

the

supply

reel.

(e.g.

slightly

touching

the

supply

reel).

NOTES:

1.

As

head

adjustment

greatly

affects

tape

deck

performance,

be

sure

that

these

adjustments

are

carried

out

properly.

.

Be

careful

not

to

use

magnetized

tools

near

the

heads.

.

As

the

level

of

old

tape

varies

greatly.

use

new

tape.

4.

Demagnetize

heads

before

and

after

head

adjustment.

i)

wW

Vil.

AMPLIFIER

ADJUSTMENT

HIGH

SENSITIVITY

ene

AC

VOLTMETER

OSCILLATOR

OUT

IN

FREQJENCY

COUNTER

Fig.

11

Instruments

Connection

1.

MODEL

GX-4000D

‘ee

®)

VES

23mH

REC

AMP

BIAS

FILT|

CtaRT

SAS

FER

YRE_5KB

\U

METER

SENS

(RIGHT)

VR4

5KB

REC

LEVEL

1

2,

23

ni

AMP

BIAS

FILT

IGHT)

6

FireR

VL4

23m

REC

AMP

BIA!

igus

PUTER

RESPONSE

wag

7

a

ey

raton

me

{RIGHT}

Be

LeveL

VU

to

WL

Adjust

from

the

oppose

sae

(@)

Fig.

12.

Amp

P.C

Board

LE-5801A

(GX-4000D)

Step

|

Adjustment

Test

Tape

\

Adjustment

Item

{Supply

Signal

Mode

Point

Result

Remarks

Playback

|

700

H

L

Level

|

7-1/2

-

VR2

50

kB(L)

haar

i

;

f

2

ied

+

Monitor

Switch

to

Adjustment

eae

a

vrs

50

BR)

proce

“TAPE

:

i

|

|

|

(0.778V)

APE”.

VU

Meter

700

Hz

i

|

2

Sensitivity

7-1/2

ips

pray

|

WR3

5

KB(L)

|

OVU

Adjustment

|

Test

Tape

VR6

5S

KB(R)

indication

|

SCOTCH

#2

re

Frequency

tape

1,000

.

(Bae

3

|

Response

ipod

Ha

|

RECE

|

MCL

ZORL)

Py

GGL.

4

|

SARC

SRE

ate

ee

aeer:

Adjustment

-20

VU

pre

See

sR

|

aa

ica

ine

recording

4

poets

ci

SCOTCH

#211

ood

tape

1,000Hz

|

REC/

|

REC

Volume

i

oe

Set

Monitor

Switch

to

’

ecording

|

0

VU

recording

PLAY

|

(VRB

SOKA)

|

775yy_

|

“TAPE”

eve.

:

Adjustment

SCOTCH

#211

[

REC/

|

VRI

Sk

O.dbm

tape

1,000

Hz

B(L)

2

Set

M

i

4

;

+0.5

dB

onitor

Switch

to

OVUrecording

|

PEAY]

VR4

SBR)

|g

azsyy_|

“SOURCE™

oe

an

ae

5

re

cant

5

Adjustment

Test

Tape

Adjustment

|

Step

lied

Supply

Signal

|

moi

Paint

Result

Remarks

os

ae

Distortion

1,000

Hz

5

Factor

0

VU

REC/

Less

than

(Refer

to

NOTE

5)

‘

2

A

PLAY

1.0%

j]

eA

recording

a

PB

Amp

Bias

100

kHz

Minimum

Set

Monitor

Switch

to

6

Filter

from

an

REC

as

=

aes

AC

Voltmeter

|

“TAPE”.

Adjustment

oscillator

7

m™

indication

(Refer

to

NOTES

6,

7)

T

.

:

REC

Amp

Bias

100

kHz

Minimum

Set

Monitor

Switch

to

7

Filter

from

an

REC

bot

5

aay

AC

Voltmeter

|

to

“SOURCE”.

Adjustment

oscillator

"

indication

(Refer

to

NOTES

6,

7)

|

=e

ack

os

a

Chart-1

NOTES:

1.

Output

Level

Control

should

be

at

maximum.

2

3

4

5

6

d,

.

Except

for

Step

3,

set

tape

speed

to

7-1/2

ips.

.

Set

tape

selector

to

Low

Noise

position.

.

(L)

=

Left

Channel,

(R)=

Right

Channel.

_

If

it

does

not

comply

with

the

specifications,

repeat

Steps

3,

4

and

re-adjust.

.

Unless

the

core

is

moved

intentionally

this

adjustment

is

not

necessary.

.

Adjust

the

oscillator’s

frequency

to

give

a

frequency

counter

reading

of

100

kHz.