Hitachi CMT2988-981 User manual

HITACH!|

=e

|

CMT2988

-051

SERVICE

MANUAL

-081

PALISECAMINTSG

|

AIPLSChassis

He

15

NICAM

TELETEXT

981

fp

=o

|

owe)

TO.

adapter

=oat

[o@a

[oO

|

ix

:

USERRA

OLN,

BIEN

ROAM

MERRIE

“RAS

LATA)

BIR”

R

“SARE

LAER”

PER.

.

CAUTION:

Before

servicing

this

chassis,

it

is

important

that

the

service

technician

read

the

‘Safety

Precau-

tion”

and

“Product

Safety

Notices”

in

this

service

Manual.

BR

CONTENTS

ABUZZ

LAUPER

ccereeteeeee

eee

tee

ees

2

Safety

precautions

..........ssessserevereneeesers

5

ABW

BLS

LE

BOTE

RB

cee

9

Product

safety

notice

...........ssseeseeereeetee

5

Ay

FR

G_LEBOE

ESB

cee

eeeeteeeeeeeeeee

3

Technical

cautions

.........:.:ssereereeeeeseerers

6

FARR

Fcc

r

ee

cereseee

cece

eeeeneeeeeresttneersceeens

3

Technical

specifications

.......sserrrerees

6

TE

BBB

Bec

ereccec

tees

teeeeerteereeeseneeeannerees

3

Main

features

..........:..ceseeeeneeeeeeeereseeees

6

FE

Es

Ga

OE

ee

4

Names

of

controls

........essecccesseeseeseeeeees

7

Bee.

4

Remote

control

unit

......0.:cssseseeeeeeeeeeeees

7

ASABE

eee

cece

teeeeeeeeeeeenernneeeeeeseneeteenees

8

Wiring

diagram

.......ccccsecseeseecetceneesceeees

8

FRAC

PA

RAUB]

cccceeeeceeeeeereeeereeneeneeeeeetens

11

Basic

circuit

diagram

............+:sessereeeee

il

EYURU

BR

BE

Bl

ccecceeceee

cee

eeeececeteeeeetereeteees

20

Printed

wiring

board

..........++0esesseeeeeees

20

PR

ARTE

PE

ee

eec

ce

cceeceeeneaeeeteererseees

renee

95

i

Replacement

parts

list...........cseeeseereeeee

25

ARERR,

RASERANS

ALR

RM.

SPECIFICATIONS

AND

PARTS

ARE

SUBJECT

TO

CHANGE

FOR

IMPROVEMENT

5

Bite

COLOUR

TELEVISION

September

1992

Consumer

Electronics

Division

CMT2988

ARMAELHRARR

BG:

AR

ea

(FS

ee

A

a

in

ESE

HE,

Pr

LAA

AR

ASS

A

Se

eS

PP

RY

FRG

Ta

BA

PARED

A

EK

Ee

RS

as,

BRE

WAGE

SF

P

ITA

BIR

1.

Bese

AL

FC

BY

pe

BR

BAR

ER

7A

it

EB

FaVPA

re

BB

Re

RRR

SS

ai

i

od

BY

AAT

BSE,

BUR

EER

ERERA

A

HBS

2.

Ae

ae

A

Se,

A

Be

AR.

FESR

AVIS,

7).

38

Be

BM]

28

PA,

AREAS ERD

+

ES

es

RRS

3.

PARE

ZARB

RRS

Ree.

CE

Fe

TE

ER

FE

BA BB

is

Be

AMV,

ZR

IE

HEBD

5

|

te

ELE

4.

BERRISHE—

se

(ie

FA

Bik

MTHS

HO

Ee

TUTE

LB

EA

RT,

BE

PETRIE

EE

BT

HEA

TT

(8

A

RR

HS

PR

RE

BR,

LAR

a

AR

et

FEZ

BB

ACHR,

5.

SREB

oe

ibe

SSS

Le

RAAT

LAT,

BRS

A

RB

aK

UR

AR

a

LR

EERE,

LAER

BERR,

ICEBAR

ARES

A

ERAS

eRe

RE

Uae

8

EB

12

7A

REM

KE

Hes

Li

BB,

BBA

RRR

TUT

SRR

,

LRA

A

CRRA

EIZS

,

te

ik

SE

UR

fib

BEE

YY

BS

He

BY

i

J

BZ

Pd

BY

AI

ERA

ANP)

9S

7

SSB

RE

CTL

ELIE

OO

TK

FEB

FF).

2,

FEE

URE

RR

EY

BY

Hj

BY

eB

ZA

4

FRAY

BC

TAC

EE

(1

ay)

i

A

RES,

AST

DA

BE

A:

Pia

BA

BLE

X

St

ie

HUGE:

ss ah

PRAT

Ee

OY

XR,

FL

BEBO

UREA

ES.

Arse

ah

En

RAT

BR

EE

A

widacat,

HX

ARR.

FT

ReARARDH

Ik

XP

REE

IL,

BEACH

RR

A

Rp

as

—~

ae

58

FB

2

Be

AY

Ae

BURE

REA

RRL

BIA

ERO

EPRRGHRER

MLLER,

ERR

PP

RAS31

SFR,

MRT

FE

ee

es

BY

BRR

HDRES

,

BRE

HED

7c)

AU

Ee

pc)

ap

Ye

{RHS31.

SF

KR.

Rian

Ein

ARE

p

BER,

mA

AY

(

—

)

Siig

FS

Be

WS

i

Re

sm,

(AF)

SEER

Rem

L,

(BeBe

PRR)

BE

EPS

ma

LUA,

HERR

ba

Bl.

AMS

BRELHERRA

Bl,

SiR

ie

ES

RIS

ERMERE,

SSR

TMERE

ER

LEST

MR,

if

ELEN

Gb

GE

FA

A

ce

EE

BR

BH

PEt

RFE

FY]

RBIS

AE

8

ETRE

RA

ERE

(38

KIRIE

FB

AEE

AAAS

HE

KOREA,

FESS

ARSE

ATHY

fi

A

Se

EPA

A

SC

BRAD

Re

BSS

BS

HE.

|

HORS

8

FASE

8

ABS

FR

_LHITACHI

ArH

AD

eH

AE

TEI

RA

HE

«AERA

ea,

ee

ER

RAL

XR

SB,

HITACHI

S482

225

7B

8S

Jy

BME,

EOE

HOLMES,

USER

Ree

HHITACHIMMSEA,

WiaHITACHIS8

8

aR

ZTSUR

ET

ARISE,

FD

ee

A

es,

a

CMT298%

BBR

LAER

SIA

SRRARERNRE

1.

$#SERERAREERRARREGE

(BRE)

MGR

6.

ASSES

PTR

ADA

LEE

RES

BS

2

TAP

rae

Heth

(BA

REE

BR)

ZT.

EHIME,

TERA

A

RE

ER

132K,

2.

FEHR

ERE,

Ae

Te

RE

A

LEE

a

STR

EIR,

JENNA

A,

IRE

€RRK,

HET

RERRER

735

OF

(KEL

F

MRIS.

1.458232

+10%

7.

SERRE

T

RRS

EU

Bd

TB

(i

1b

PH

RE

)

8.

SERRE

RREAMY.

3.

Ascii

A

RSE

«132+

31K,

+:

Bim

LER

RRR

AR

AS

EET,

GF

4.

PRS

—

e288

.741.0F

KR.

—

ISAS

EPA

BA

(SERGEY

ee

ee)

5

.

BrbAeeS

Ay

Se

URBSEA,

KS

3

PPR

RAE

ExCCE

RM,

ARS

ERCR

AR

bik

ER

RO71L

AP,

WO

1

ATA.

,)

RO71

Jig

e—wW—

R969

vRg51

ERD

1

15KQ

50KO-B

Jig

Hig

wees

2

MERER

HS

HRIBZE

[

ig

RARIR

A

~~]

7SEKME

(AS2E

HpZ!

)

625-(8

4

B.G/I/D-K/H

PAL,

#2

BR

A68KRT370X

B.G/D.K/K’

SECAM

ae

13cm

X

6em

(

X<

2)

NTSC50

idles

Peres

PUR

A

KN

525-feR

~M/NTSC

aa.

NTSC3.58-5.5/6.0/6.5

|

seit

125

x24

10K

NTSC

4.43-5.5/6.0/6.5

a

BEE

1101K/1274K/2201K

50/60

PAL60

cia

BE

ike

220KK-240K

50/60AiR

(F4-081

)

GE

6B)

CCIR

:

E2~12,

E21~69,

Bon

ACG

01~3,

S1~10,

$11~20

ARR

180H.

[ies

OIRT

R1~12,

R21~69

HE

(4A)

45.0

47036

~96sIbak/

|

A:

Ji~12,

J

13~62

2H

8:

US2~13,

J~W,

IF

R

at

BK)

US

14~69

ne

76.0X59.0X49.5

Sie,

KB:

UK21~69

(BEX

i

XR)

Hoy

=:

C1~12,

C13~57

we

oe

5

UOETERE

TBE

ELAR

PA

HB

A

1

ASEMSRERSEE

2

BRR

A

ti

RRR

_—3—

CMT2988

SBMBRAMAR

—4—

2m

/

St

PABA

BRE

Semis

ON

TIMER

(sempiantet

Haale

ISU

Edd

AV

IN

(58

FBR

8R

A

)

iF

Hk

A

ETE

O;]oO!)

NT Mi

on]

—

}

OO]

dw

|

Be

—

oO

HRA

65

Br

/

BE

ray

e

RiRaR

A

Stig

FE

roa

iw)

FERRO

stig

—

Ww

SB

ORB

S38

3

Fe

BA

a

i

AV

IN/OUT

(Ree

TSR

A

/

BR

A

)

Sa

12

|

#R

A

Sede

13

|

Shi

Bisset

at

is

ER

lel

(RATA

Ol,

oOInNI

RD]

oa]

&

aie

i

fan)

cae

A

TT

[Sn

Cn Tn

P|

DL

7

SRR

ASSETS

#3

fl

23

|

SRA

AY

Sk

RRS

as

N

#A®TELETEXT

BPH

see

P

RRB

ES

BARRE

SAFETY

PRECAUTIONS

WARNING:

Since

the

chassis

of

this

receiver

is

connected

to

one

side

of

the

Mains

Supply

during

operation,

service

should

not

be

attempted

by

anyone

unfamiliar

with

the

precautions

necessary

when

working

on

this

type

of

equipment.

The

following

precautions

should

be

observed.

1.

Do

not

install,

remove,

or

handle

the

picture

tube

in

any

manner

unless

shatter-proof

goggles

are

worn.

People

not

so

equipped

should

be

kept

away

while

picture

tubes

are

handied.

Keep

picture

tube

away

from

the

body

while

handling.

2.

When

replacing

chassis

in

the

cabinet,

all

the

protective

devices

are

put

back

in

place,

such

as;

barriers,

non-

metallic

knobs,

adjustment

and

compartment

cover

or

shields,

isolation

resistors-capacitors,

etc.

3.

When

service

is

required,

observe

the

oritinal

lead

dress.

Extra

care

should

be

taken

no

assure

correct

lead

dress

in

the

high

voitage

circuitry

area.

4,

Always

use

the

manufacturer's

replacement

component.

Especially

critical

components

as

indicated

on

the

circuit

diagram

should

not

be

replaced

by

other

makes.

Furthermore

where

a

short

circuit

has

occurred,

replace

those

components

that

indicate

evidence

of

overheating.

5.

Before

returning

a

serviced

receiver

to

the

customer,

the

service

technician

must

thoroughtly

test

the

unit

to

be

certain

that

it

is

completely

safe

to

operate

without

danger

of

electrical

shock,

and

be

sure

that

no

protective

device

built

into

the

instrument

by

the

manufacturer

has

become

defective,

or

inadvertenly

defeated

during

servicing.

Therefore,

the

following

checks

are

recommended

for

the

continued

protection

of

the

customers

and_

service

technicians.

INSULATION

Insulation

resistance

between

the

mains

poles

and

any

accessible

metal

parts

should

not

be

less

than

7MQ.

at

500V

DC.

Also,

no

flashover

or

breakdown

should

occur

during

the

dielectric

strength

test,

to

apply

4KV

AC

for

one

minute

between

the

mains

poles

and

any

accessible

metal

parts.

X-RADIATION

TUBES:

The

primary

source

of

X

radiation

in

this

receiver

is

the

picture

tube.

The

tube

utilized

in

this

chassis

is

specially

constructed

to

limit

X

radiation.

For

continued

X

radiation

protection,

the

replacement

tube

must

be

the

same

type

as

the

original,

HITACHI

approved

type.

CMT298&

High

Voltage

This

receiver

is

provided

with

a

hold

down

circuit

for

clearly

indicating

that

voltage

has

increased

in

excess

of

a

predetermined

value.

Comply

with

all

notes

described

in

this

Service

Manual

regarding

this

hold

down

circuit

when

servicing,

so

that

this

hoid

down

circuit

is

operated

correctly.

Serviceman

warning

With

minimum

Black

Level

and

Picture,

the

operating

high

voltage

in

this

receiver

is

lower

than

31.5kV.

In

case

any

component

having

influence

on

the

high

voltage

is

replaced,

confirm

that

high

voltage

with

minimum

Brightness

and

contrast

is

lower

than

31.5kV.

To

measure

H.V.

use

a

high

impedance

H.V.

meter.

Connect

(—)

to

chassis

earth

and

(+)

to

the

CRT

anode

button.

(See

the

following

connection

diagram).

NOTE:

Turn

the

power

switch

off

without

fail

before

the

connection

to

the

Anode

button

is

made.

CRT

ANODE

HIGH

IMPEDANCE

H.V.

METER

CHASSIS

GROUND

PRODUCT

SAFETY

NOTICE

Many

electrical

and

mechanical

parts

in

HITACHI

television

receiver

have

speciai

safety

These

characteristics

are

often

not

evident

from

visual

inspection

nor

can

be

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

this

Service

Manual.

Electrical

components

having

such

features

are

identified

by

marking

with

a

A\

mark

in

the

schematics

and

on

the

replacement

parts

fist

in

this

Service

manual.

The

use

of

a

substitute

replacement

component

which.

does

not

have

the

same

safety

characteristics

as

the

HITACHI

recom-

mended

replacement

one

shown

in

the

parts

list

in

this

Service

Manual,

may

create

electrical

shock,

fire,

X

radiation,

or

other

hazards.

Product

Safety

is

continuously

under

review

and

new

instructions

are

issued

from

time

to

time.

For

the

latest

information,

always

consult

the

current

HITACHI

Service

Manual.

A

subscription

to,

or

additional

copies

of,

HITACHI

Service

Manuai

may

be

obtained

at

a

nominal

charge

from

your

HITACH!

SALES

CORPORATION.

SMT2988

TECHNICAL

CAUTIONS

High

voltage

limiter

circuit.

operation

check

1.

2.

anode

(anode

cap)

and

GND

(CPT

grounding

lead).

Receive

the

broadcast

signal

and

set

the

brightness

and

contrast

VRs

to

max.

Set

the

beam

current

to

1.15mA

10%

:CMT2528

1.45mA+10%

:

CMT2928

(After

cut-off

adjustment)

.

Set

the

AC

input

voltage

to

132-13V.

.

Check

that

the

constant

high

voltage

is

28.7£1.0kV

at

this

time.

.

Turn

the

switch

of

the

set

to

off

and

connect

the

jig

shown

in

Fig.

3

at

both

ends

of

R971

as

shown

in

Fig.

1.

Power

Supply

P.W.B.

CPT

Earth

Wire

Connect

the

high

voltage

voltmeter

between

the

CPT

D.C

Voltage

Divide

6.

With

the

brightness

and

contrast

VRs

left

as

set

in

item

2

and

with

the

AC

input

voltage

stabilized

at

132V,

turn

the

set

on

and

increase

input

voltage

and

check

that

the

picture

disappears

with

a

high

voltage

of

35.0kV

or

less.

7.

Turn

the

switch

of

the

set

to

off

immediately

after

the

check

is

completed.

8.

Remove

the

adjust

jigs

and

high

voltage

voltmeter.

Note:

When

connecting

disconnecting

the

high

voltage

voltmeter

to

from

the

anode

cap,

be

sure

to

turn

the

switch

of

the

set

off

and

do

it

after

the

residual

high

voltage

is

discharged

to

the

chassis

because

the

high

voltage

may

remain

at

the.

anode

cap.

eo—_w—e

R969

vrgs1

Ge

Fig.

1

15KQ

50KO-B

Jig

Digital

Voltmeter

Fig.

3

Specifications

B.G/I/D.K/H_

PAL

B.G/D.K/K’

SECAM

NTSC50

M/NTSC

NTSC3.58-5.5/6.0/6.5

NTSC4.43-5.5/6.0/6.5

PAL60

625-lines

Reception

system

|

525-lines

Hong

Kong,

U.K.

:

UK21~69

China

:C1~12,

C13~57

CCIR

:E2~12,

E21~69,

01~3,

S1~10,

S11~20

Channel

coverage

|OIRT

:<R1~12,

R21~69

-

{Frequency

range

JAPAN

:

J1~12,

J13

~62

hea

U.S.A.

>

US2~13,

J~W,

470MHz~863MHz

US14~69

Aerial

input

Color

picture

tube

75Q

unbalanced

type

A68KRT370X

13cm

X6cem(X

2)

12cmX6em(X

1)

6cm

X

4cm(X

2)

12WX2+10W

AC110V/127V/220V

50/60Hz

AC220V—240V

50/60Hz

.

(—081

only)

Speaker

Sound

output

Power

supply

180W

45.0

Power

consumption

Weight

(kg)

Dimensions

WXHXD

(cm)

Country

of

manufacture

76.0X59.0X49.5

Japan

*

Specifications

are

subject

to

change

without

notice

to

improve

performance.

Main

Features

1.

Advanced

full

function

remote

control

system

2.

Front

video

input

terminals

CMT2988

Names

of

controls

7

Program

up/down

button

2

13

|

External

speaker

select

switch

AV

IN/OUT

terminals

Remote

control

transmitter

Power

ON/OFF

Input

select

2

Programme

selecter

Dynamic

noise

Program

up/down

A

reduction

15

|

Mute

i

16

|

Volume

up/down

B

al

Cc

D

E

2

Sound

mode

F

TV/VTR

select

:

Exclusive

VTR

buttons

;

ra

A~N

shows

the

key

function

in

Teletext

mode.

7

O,

P_

shows

the

key

function

in

Sound

multiplex

mode.

CMT2988

H

im

WIRING

DIAGRAM

A

ee

(vy)

\Y

a

(gO

GY

26

=)

a

A

Le

COP

Yay

Oe

aaNoR

5

K

E'

GG

ed

Vv.

Cc

uve

PIG

}

WIRE

CRAMP15

ripe)

|

K

da

(

Lay

C

PT

FURIE

Be

AK

CPT

P.W.B

: |

=a

”

B

3|

fem

E

RAR

B

;

4)

#

fil)

EV

FEB

AR

C

=

|

5]

eelEnmI

a

esARD

D

o|

sesinaresaE

ae

7)

ASB

He

ED

all

Be

BR

AR

Power

Output

P.W.B

=A

:

FOMEAMAAEK,

463

PHEBAY

Bind

the

wires

of

the

3P

connector

using

a

tie-band

so

that

the

wires

do

not

touch

the

terminals

of

the

power

ihe

7S

BU

UB

9

SAG

cuaak.

Aa

RES

ana]

Le

AS

Be

EBL

A

Perform

wiring

without

touching

the

heat

sink.

174

P

M

Bea

a8

7

BR

Perform

wiring

along

the

PM

connector.

$£

7542

PRE]

/

Basic

CIRCUIT

DIAGRAM

BURR

EL

AEM:

MMA

A

REBEL

ALE

ALATA

7

ni

OUT

TRE

HE,

|

UCT

SE

MALES,

AMINA

AERIS

MASE

LAER”

—

EH,

B/N

Ly,

OY

ARE

AS

BE

iT

BE

(IRB

BS

Oe

EAE,

ry

- ©

RENN

SY

GENOMES

fe

menemeennens

-

SS

SF

A

SS

SF

A

SS

A

NANT

on

-

MAIN

P.W.B

ai

is

=

31)>—~<

~V.P

x

Ww

2/3

csoa2

-

6

ne

0.01

I

26)—<¢

PC

IN

23)>—<

PC

OUT

1)

A

nav?

100

1/ow

R875

100

1/ew

2

RY

100

1/6

SECAM

05010

2863413

2

a

'

Qa84

:

2801514

)

'

z

cs

casi

-]

100/16

(ea)

TO

AV

1/0

P.w.

8.

3?

<

©)

>)

©)

Re?!

390

1/8

cape

=

129

REE?

180

t220)}

@63

oe

1/ew

|

100

CPT

P.W.B.

NN

RR

~5004

205002-500.

23)

PAL

sw

TO

AV

1/0

P.W.B.

(ec]

TO

AV

I/D

P.W.B-

®

Qo

@

©

Q

© @

©

SHARP

we

es

e316

+

100/162

307

A339

9.001

:

Soe

c7

185270

33P/7500

8701

2803413

100

)

TO

POWER

P.

Ww. 6B.

A798

160

14/2)

20795

HZS6C2

100/25

TO

AV

1/0

P.Ww.8.

me

scales

Ral

eta:

A

ee

R1375

1.2%

ay

=

ft)

250673)

:

R1374

C1330

5604.

7780

A1378

1/ou

BP.

18K

é

3

oy

a

EE

SS

FS

ff

A

<

SRNNNONNNNSCNI

4

2

3

4

5

CRRAMERARBM,

RUHEtEHE,

SICA

Re

AHS

yew),

@

soft

Fy

Ay

ft

BS

A a

BEE

(

PO

HB

100KQ

/V)

BIS.

CRSA

BR

AIR

T

EEABERER.

Hitachi CMT2988-981 User manual

Popular TV manuals by other brands