JVC AV-14F43/BK, AV-20N43/BK, AV-21D43/BK Service Manual

SERVICE MANUAL

COLOUR TELEVISION

AV-21D43
AV-20N43

AV-14F43

BASIC CHASSIS

[ RM-C368GY ]

[ AV-14F43

AV-21D43
AV-20N43

AV-14F43

/BK

]

[ AV-20N43

/BK

/BK

/BK

/BK

]

CG

[ AV-21D43

/BK

]

CONTENTS

SPECIFICATIONS ････････････････････････････････

!

SAFETY PRECAUTIONS ････････････････････････････････

!

FEATURES････････････････････････････････

!

FUNCTIONS ････････････････････････････････

!

MAIN DIFFERENCE LIST ････････････････････････････････

!

SPECIFIC SERVICE INSTRUCTIONS ････････････････････････････････

!

SERVICE ADJUSTMENTS ････････････････････････････････

!

PARTS LIST ････････････････････････････････

!

★ OPERATING INSTRUCTIONS
★ STANDARD CIRCUIT DIAGRAM ････････････････････････････････

1

････････････････････････････････････････････････････････････････

････････････････････････････････････････････････････････････････

･････････････････････････････････････････････････････････････

････････････････････････････････････････････････････････････････

･･･････････････････････････････････････････････････････

････････････････････････････････････････････････････････････････

･･･････････････････････････････････

････････････････････････････････････････････････････････････････

････････････････････････････････････････････････････････････････

････････････････････････････････････････････････････････････････

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････････････････････････････････････････････････････････････････

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････････････････････････････････････････････････････････････････

･････････････････････････････････････････････････････

････････････････････････････････････････････････････････････････

････････････････････････････････････････････････････････････････

････････････････････････････････････････････････････････････････

････････････････････････････････････････････････

････････････････････････････････････････････････････････････････

COPYRIGHT © 2002 VICTOR COMPANY OF JAPAN, LTD.

･････････････････････････････ 2

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･･･････････････････････ 3

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････････････････････････････････････････････････････････････････

･･･････････････････････ 7

･･････････････････････････････････････････････

･････････････････････ 19

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････････････････････････････････････ 37

････････････････････････････････････････････････････････････････

･･･ 4

･･････

･･ 5

････

･････････････ 8

･･････････････････････････

････････････････ 2-1

････････････････････････････････

No. 52036
Aug. 2002

A

V-21D43

A

A

V-20N43
V-14F43

SPECIFICATIONS

ITEM

Dimensions(W×H×D)

Mass (Net)

TV RF System B/G,I, D/K,

RF Mode

Colour System

Picture Tube

High Voltage

Receiving

Intermediate
Frequency

Colour Sub Carrier Frequency

VIDEO Mode

VHF (VL) 46.25MHz～168.25MHz

VHF (VH) 175.25MHz～463.25MHz

UHF 471.25MHz～863.25MHz

CATV

VIF Carrier 38.0MHz

SIF Carrier

598mm×468mm×478mm

21kg

PAL / SECAM

PAL / SECAM
NTSC3.58 / NTSC4.43

Visible size: 51cm measured
diagonally

26.5kV±1.5kV(at zero beam
current)

Cable TVs of Mid (X-Z, S1-S10)
Super (S11-S20) & Hyper (S21­S41) bands receivable

32.5MHz(5.5MHz)

31.5MHz (6.5MHz)

32.0MHz (6.0MHz)

PAL (4.43MHz),
SECAM(4.40625MHz/4.25MHz)
NTSC (3.58MHz / 4.43MHz)

CONTENT

AV-21D43/BK AV-20N43/BK AV-14F43/BK

619mm×458mm×488mm 462mm×340.5mm×375mm

19kg 10kg

Visible size: 48cm measured
diagonally

Visible size: 34c m measured
diagonally

22.5kV±1.5kV(at zero beam
current)

Power Input

Power Consumption 105W (Max) / 68W (Avg) 90W (Max) / 60W (Avg) 70W (Max) / 47W (Avg)

Speaker 5cm×12 cm, Oval type×25cm×9 c m, Oval type×2

Audio Output A2 / Billingual,5W (monaural) A2 / Billingual,3W (monaural)

Aerial Input Terminal 75Ω Unbalanced

Input Video 1V(p-p), 75Ω (Front / Rear)

Output Video 1V(p-p), 75Ω

Headphone jack

Remote Control Unit

Rating V oltage AC110～240V, 50 / 60Hz

Operating Voltage AC90～260V, 50 / 60Hz

500mV(r ms) (-4dBs), High

Audio

Audio

impedance,
RCA×2 (Front / Rear)

500mV(r ms) (-4dBs), Low
impedance,

RCA×1

3.5 mm mini jack

RM-C368GY
(Battery size : AA / R06 / UM-3×

2)

Design and specifications are subject to change without notice.

2

No. 52036

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SAFETY PRECAUTIONS

V-21D43
V-20N43

V-14F43

1. The design of this product contains special hardware, many
circuits and components specially for safety purposes. For
continued protection, no changes should be made to the original
design unless authorized in writing by the manufacturer.
Replacement parts must be identic al to those used in the original
circuits. Service should be performed by qualified personnel
only.

2. Alterations of the design or circuitry of the products should not be
made. Any design alterations or additions will void the
manufacturer's warranty and will further relieve the manufacturer
of responsibility for personal injury or property damage resulting
theref rom.

3. Many electric al and mechanical parts in the products have
special safety-related characteristics. These characteristics are
often not evident from visual inspection nor can the 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 the parts list of Service manual. Electrical

components having such features are identified by shading
on the schematics and by (!!!!) on the parts list in Service
manual. The use of a subst itute replacement which does not

have the s ame safety characteristics as the recommended
replacement part shown in the parts list of Service manual may
cause shock, fire, or other hazards.

4. Don't short between the LIVE side ground and ISOLATED

(NEUTRAL) side ground or EARTH side ground when
repairing.

Some model's power circuit is partly different in the GND. The
differenc e of the GND is shown by the LIVE : (") side GND, the
ISOLATED(NEUTRAL) : (#) side GND and EARTH : ($) side
GND. Don't short between the LIVE side GND and
ISOLATED(NEUTRAL) side GND or EARTH side GND and
never meas ure with a measuring apparatus (oscilloscope etc.)
the LIVE side GND and ISOLATED(NEUTRAL) side GND or
EARTH side GND at the same time.
If above note will not be kept, a fuse or any parts will be broken.

5. If any repair has been made to the chassis, it is recommended
that the B1 setting should be checked or adjusted (See
ADJUSTMENT OF B1 POWER SUPPLY).

6. The high voltage applied to the picture tube must conform with
that specified in Service manual. Excessive high voltage can
cause an incr ease in X-Ray emission, arcing and possible
component damage, therefore operation under excessive high
voltage conditions should be kept to a minimum, or should be
prevented. If severe arcing occurs, remove the AC power
immediately and det ermine the caus e by visual inspection
(incorrect installation, cr acked or melted high voltage harness,
poor soldering, etc.). To maintain the proper minimum level of
soft X-Ray emission, components in the high voltage circuitry
including the picture tube must be the exact replacements or
alternatives approved by the manuf actur er of the complete
product.

7. Do not check high voltage by drawing an arc. Use a high voltage
meter or a high voltage probe with a VTVM. Discharge the
picture tube before attempting meter connection, by connecting
a clip lead to the ground frame and connecting the other end of
the lead through a 10kΩ 2W resistor to the anode button.

8. When service is requir ed, obser ve the original lead dress. Extra
precaution should be given to assure correct lead dress in the
high voltage circuit area. W here a short circuit has occurred,
those components that indicat e evidenc e of overheating should
be replaced. Always us e the manufacturer's replacement
components.

9. Isolation Check

(Safety for Electrical Shock Hazard)

After re-assembling the product, always perf orm an isolation
check on the exposed metal parts of the cabinet (antenna
terminals, video/audio input and output terminals, Control knobs,
metal c abinet, screwheads, earphone jack, c ontrol shafts, etc.)
to be sure the product is safe to operat e without danger of
electr ical shoc k.

(1) Dielectr ic Strength Test

The isolation between the AC primary circuit and all metal parts
exposed to the user, particularly any expos ed metal part having a
return path to the chass is should withstand a voltage of 3000V
AC (r.m.s.) for a period of one second.

(. . . . Withstand a voltage of 1100V AC (r.m.s.) to an applianc e

rated up to 120V, and 3000V AC (r.m.s.) to an appliance rated
200V or more, for a period of one second.)
This method of test requires a test equipment not generally found
in the s ervice trade.

(2) Leakage Current Check

Plug the AC line cord directly into the AC outlet (do not use a line
isolation transformer dur ing this check.). Using a "Leakage
Current T ester", measure the leakage current from each exposed
metal part of the cabinet, particularly any exposed metal part
having a return path to the chassis, to a known good earth
ground (water pipe, etc.). Any leakage c urrent must not exceed

0.5mA AC (r.m.s.).
However, in tr opical area, this must not exceed 0.2mA AC
(r.m.s.).

"""" Alternate Check Method

Plug the AC line cord directly into the AC outlet (do not use a line
isolation transformer during this check.). Use an AC volt meter
having 1000 ohms per volt or more sensitivity in the following
manner. Connect a 1500Ω 10W resistor paralleled by a 0.15µF
AC-type capacitor between an expos ed metal part and a known
good earth ground (water pipe, etc.). Measure the AC voltage
across the resistor with the AC voltmeter. Move the resistor
connection to each exposed metal part, particularly any exposed
metal part having a return path to the chassis, and measure the
AC voltage across the resist or. Now, reverse the plug in the AC
outlet and repeat each measurement. Any voltage meas ured
must not exceed 0.75V AC (r.m.s.). This corresponds to 0.5mA
AC (r.m.s.).
However, in tr opical area, this must not exc eed 0.3V AC (r.m.s.).
This corresponds to 0.2mA AC (r.m.s.).

AC VOLTMETER
(HAVING 1000 Ω/V,
OR MORE SENSITIVITY)

0.15μF AC-TYPE

PLACE THIS PROBE

1500 Ω 10W

GOOD EARTH GROUND

ON EACH EXPOSED
METAL PART

No.52036

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V-21D43

A

A

V-20N43
V-14F43

FEATURES

" New chassis design enables use of an inter active on-screen control.
" Wide range voltage (rating voltage :110V～240V / operating voltage : 90V～260V) AC power input.

" With AUDIO / VIDEO INPUT & OUTPUT terminal.
" MUTING button can reduce the audio level to zero instantly.
" Functional remote control to operate TV set (for channel s elect, volume c ontrol, power ON/OFF, etc.) from a distanc e.

2

C bus control utilizes single chip ICs for IF, V/C, DEF. VSM PRESET, PRESET & SETUP TOUR.

" I
" By means of AUTO PROGRAM, the TV stations can be selected automatically and the TV channels can also be r earranged automatic ally.
" Built-in AI ECO (ECONOMY, ECOLOGY) sensor.

In accordance with the brightness in a room, the brightness and / of contrast of the picture can be adjusted aut omatically to make the
optimum picture which is easy on the eye.

" Built – in ON TIMER, RETURN + & CHILD LOCK.
" Built–in PICTURE BOOSTER circuit newly, to amplify the broadcasting wave in the area where wave is weak.

SYSTEM BLOCK DIAGRAM

"

IC702

MEMORY

SCL2/SDA2

IC701

MICRO

COMPUTER

IC301

VIDEO/CHROMA

DECORDER

SCL1/SDA1

TU001

TUNER

4

No. 52036

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FUNCTIONS

■ FRONT PANEL

V-21D43
V-20N43

V-14F43

[AV-21D43/BK]

10 9 1 2 3 4 5 6 7 8

This illustration shows the AV- 21D43
20N43

/BK

and AV-14F43

models for the arrangements of buttons, lamps, etc. on the front panel.

/BK

is different, this illustration is applicable to both

/BK

. Although the design of the AV-

■ REAR TERMINAL

MENU butt ons

1

(Replacement of IC301)

CHANNEL －/＋ buttons

2

VOLUME －/＋ buttons

3

(Replacement of IC301)

AI ECO sensor

4

REMOTE CONTROL sensor

5

ON TIMER lamp

6

POWER lamp

7

MAIN POWER button

8

A/V INPUT terminal

9

HEADPHONE jack

10

ANT Terminal

1

2

1

3

4

5

VIDEO INPUT Terminal

2

AUDIO INPUT Terminal

3

4

AUDIO OUTPUT Terminal

VIDEO OUTPUT Terminal

5

No. 52036

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A

V-21D43

A

A

V-20N43
V-14F43

■ REMOTE CONTROL UNIT

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

PICTURE BOOSTER key

1

ECO SENSOR key

2

SOUND SYSTEM key

3

4

COLOUR SYSTEM key

TV/VIDEO key

5

Ⅰ/Ⅱ Key

6

OFF TIMER key

7

CHANNEL SCAN key

8

RETURN＋key

9

DISPLAY key

10

11

CHANNEL－/＋ key

12

POWER key

PICTURE MODE key

13

14

Number (CH.) key

15

－/－－key

16

MUTING key

MENU key

17

MENU ▲/▼ key
MENU －/＋ key

18

VOLUME－/＋ key

6

No. 52036

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MAIN DIFFERENCE LIST

Model Name

!

Part Name (Item)

MAIN PWB SCG-1435A SCG-1434A SCG-1433A

! FRONT CABINET LC11129- 021A-H LC10438- 032A-H LC10831- 030A-H

! REAR COVER GG10130-005A-H LC10448- 002B-H CM12961-D01-VH

SPEAKER QAS0086-001 CEBSS12D-07KJ2 QAS0054-001

!

PICTURE TUBE A51LMV10X A48LSD095X A34AGT13X

! DEF YOKE CE20336-00A QQD0034-001 QQD0046-001

! DEG COIL QQW0006-001 QQW0061-001 QQW0093-001

! F. B. TRANSF QQH0069-001 QQH0073-001 QQH0072-001

!

PWB STOPPER CM48144-002-H

AV-21D43

/BK

AV-20N43

/BK

AV-14F43

V-21D43
V-20N43

V-14F43

/BK

PACKING CASE GG10056-065A-H GG10056-064A-H GG10056-066B-H

Dimensions (W ×H×D) 598mm×468mm×478mm 619mm×458mm×488mm 462mm×340.5mm×375mm

Mass (Net) 21kg 19kg 10kg

Picture T ube

High Voltage

Speaker

Power C onsumption 105W (Max) / 68W (Avg) 90W (Max) / 60W (Avg) 70W (Max) / 47W (Avg)

Audio Output A2 / Billingual,5W (monaural) A2 / Billingual,3W (monaural)

Visible size: 51cm measured
diagonally

26.5kV±1.5kV(at zero beam

current)

5cm×12 cm, Oval type×25cm×9 c m, Oval type×2

Visible size: 48cm measured
diagonally

Visible size: 34cm measured
diagonally

22.5kV±1.5kV(at zero beam

current)

No. 52036

7

A

V-21D43

A

A

V-20N43
V-14F43

SPECIFIC SERVICE INSTRUCTIONS

DISASSEMBLY PROCEDURE

REMOVING THE REAR COVER

1. Unplug the power plug.

screws marked

2. As shown in figure, remove the

screw marked

3. Withdr aw the rear cover toward you.

""""

.

7

REMOVING THE MAIN PW BOARD

" After removing the rear cover.

1. Slightly raise the both sides of the MAIN PW BOARD by hand.

2. Withdr aw the MAIN PW BOARD backward.
(If necessary, take off the wire clamp, connectors etc.)

REMOVING THE SPEAKER

" After removing the rear cover.

screws marked

1. As shown in figure, remove the

2. Follow the same steps when r emoving the other hand speak er.

4

####

!!!!

.

and a

CHECKING THE MAIN PW BOARD

1. To check the back side of the PW Board.

1) Pull out the MAIN PW Board. (Refer to REMOVING THE MAIN
PW Boar d)

2) Erect the PW Boar d vertically so that you can easily check the
back side of the PW Board.

[CAUTION]

" When erecting the PW Board, be careful so that there will be no

contac ting with oth er PW Boar d.

" Before turning on power, make sure that the CRT earth wire and

other connector are properly connected.

WIRE CLAMPING AND CABLE TYING

1. Be sure t o clamp the wire.

2. Never remove the cable tie used for tying t he wires together.
Should it be inadvertently removed, be sure to tie the wires with a
new cable tie.

8

No. 52036

A

A

A

FRONT CABI.

SPEAKER

CRT SOCKET

PWB

MAIN PWB

V-21D43
V-20N43

V-14F43

(××××4)

C

SPEAKER

(××××4)

C

REAR

COVER

POWER

CORD

(××××1)

B

(××××7)

A

No. 52036

9

A

V-21D43

A

A

V-20N43
V-14F43

DISASSEMBLY PROCEDURE

REMOVING THE REAR COVER

1. Unplug the power plug.

2. As shown in figure, remove the

screw marked

3. Withdr aw the rear cover toward you.

""""

.

screws marked

6

REMOVING THE MAIN PW BOARD

" After removing the rear cover.

1. Slightly raise the both sides of the MAIN PW BOARD by hand.

2. Withdr aw the MAIN PW BOARD backward.
(If necessary, take off the wire clamp, connectors etc.)

REMOVING THE SPEAKER

" After removing the rear cover.

screws marked

1. As shown in figure, remove the

2. Follow the same steps when r emoving the other hand speak er.

2

####

!!!!

.

and a

CHECKING THE MAIN PW BOARD

1. To check the back side of the PW Board.

1) Pull out the MAIN PW Board. (Refer to REMOVING THE MAIN
PW Boar d)

2) Erect the PW Boar d vertically so that you can easily check the
back side of the PW Board.

[CAUTION]

" When erecting the PW Board, be careful so that there will be no

contac ting with oth er PW Boar d.

" Before turning on power, make sure that the CRT earth wire and

other connector are properly connected.

WIRE CLAMPING AND CABLE TYING

1. Be sure t o clamp the wire.

2. Never remove the cable tie used for tying t he wires together.
Should it be inadvertently removed, be sure to tie the wires with a
new cable tie.

10

No. 52036

A

A

A

FRONT CABI.

V-21D43
V-20N43

V-14F43

SPEAKER

SPEAKER

REAR

COVER

C

(××××2)

POWER

CORD

CRT SOCKET

PWB

C

MAIN PWB

(××××2)

B

(××××1)

(××××6)

A

No. 52036

11