JVC AV-20N83, AV-21D83 Schematic

SERVICE MANUAL

COLOUR TELEVISION

AV-20N83 AV-21D83

BASIC CHASSIS

PICTURE

POWER

BOOSTER

MUTING

SYSTEM

CINEMA

COLOUR SOUND

SURROUND

ECO

SENSOR

DISPLAY

TV/VIDEO

123

OFF

TIMER

456

PICTURE MODE

789

CHANNEL

RETURN+

SCAN

0-/

VOLUME

CHANNEL

RM-C1017

RM-C1017-1H

/BK

[AV-20N83 [AV-21D83

/BK

] ]

AV-20N83 AV-21D83

POWER

B O

Y S

U R

A Y

E N

ENU

123

456

P IC

789

H A

R N

CHAN

NEL

LUM

-C 1027

RM-C1027-1H [AV-21D83 [AV-20N83

/VT

] ]

[AV-20N83

/BK

, AV-20N83

/BK

AV-21D83 AV-20N83

/VT

]

[AV-21D83

/BK

, AV-21D83

/VT

]

a SPECIFICATIONS ....................................................................................................................................2

a OPERATING INSTRUCTIONS (APPENDIX)

a SAFETY PRECAUTIONS .........................................................................................................................3

a FEATURES ..............................................................................................................................................4

a FUNCTIONS ............................................................................................................................................. 5

a SPECIFIC SERVICE INSTRUCTIONS ....................................................................................................6

a SERVICE ADJUSTMENTS ....................................................................................................................16

a STANDARD CIRCUIT DIAGRAM (APPENDIX) .................................................................................. 2-1

a PAR TS LIST ...........................................................................................................................................41

No. 52076 Dec. 2002

AV-20N83 AV-21D83

SPECIFICATIONS

Items

AV-20N83/BK

Dimensions (W × H × D)

Mass 19kg 21kg 18kg

TV RF System B, G B, G, D, K, K1, M

Colour System TV Mode PAL / SECAM PAL / SECAM / NTSC3.58 / NTSC4.43

VIDEO Mode PAL / SECAM / NTSC3.58 / NTSC4.43

Stereo System Playback only

Receiving Frequency VHF (VL) 46.25MHz – 140.25MHz (AU0 – S6) 46.25MHz – 168.25MHz (AS0 – S6)

VHF (VH) 147.25MHz – 423.25MHz (S7 – S36) 175.25MHz – 463.25MHz (S7 – S36)

UHF 431.25MHz – 863.25MHz (S37 – CHINA 57) 471.25MHz – 863.25MHz (S37 – CHINA 57)

CATV ● Cable TVs of Mid (X-Z, S1-S10)

Intermediate VIF Carrier 38.0MHz

Frequency SIF Carrier 32.5MHz (5.5MHz) 31.5MHz (6.5MHz)

Colour Sub Carrier PA L 4.43MHz

Frequency SECAM 4.40625MHz / 4.25MHz

NTSC 3.58MHz / 4.43MHz

Aerial Input Terminal 75Ø Unbalanced, coaxial

Power Input AC110V – AC240V, 50Hz / 60Hz

Power Consumption 95W

Picture Tube

High Voltage 26.5kV ± 1.5kV (at cut-off in service mode)

Speaker 5cm X 12cm Oval type x 2

Audio Output 5W + 5W

Video / Audio Input Video (1 / 3) 1V(p-p), 75Ø, RCA pin jack x 2

(1 / 2 / 3) Audio (1 / 2 / 3) 500mV(rms)(-4dBs), High impedance, RCA pin jack x 6

Component Input (Input 2)

Video / Audio Output VIDEO 1V(p-p), 75Ø, RCA pin jack x 1

AUDIO 500mV(rms)(-4dBs), Low impedance (400Hz when modulated 100%), RCA pin jack x 2

Headphone Jack Stereo mini jack (φ3.5mm)

Remote Control Unit RM-C1017-1H RM-C1027-1H

61.9cm × 45.8cm × 48.8cm 59.8cm × 46.8cm × 47.8cm 61.9cm × 45.8cm × 48.8cm

Super (S11-S20) & Hyper (S21-S41) bands receivable

(Max.)

/ 65W

(Avg.)

Visible size : 48cm measured Visible size : 51cm measured diagonally Visible size : 48cm measured

diagonally diagonally

Y:1V(p-p), positive (negative sync provided), 75Ø, RCA pin jack x 1

CB/CR : 0.7V(p-p), 75Ø, RCA pin jack x 2

(Battery size: AA/R06/UM-3 × 2)

AV-21D83/BK

Contents

AV-21D83/VT AV-20N83/VT

32.5MHz (5.5MHz)

33.5MHz (4.5MHz)

Design & specifications are subject to change without notice.

2No. 52076

SAFETY PRECAUTIONS

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

PLACE THIS PROBE ON EACH EXPOSED METAL PAR T

1500Ω 10W

0.15µF AC-TYPE

GOOD EARTH GROUND

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 identical 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 therefrom.

3. Many electrical 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 substitute replacement which

does not have the same 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 (NEU-

TRAL) side ground or EARTH side ground when repairing.

Some model's power circuit is partly different in the GND. The difference 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 measure the LIVE side GND and ISOLATED (NEUTRAL) side GND or EARTH side GND at the same time with a measuring apparatus (oscilloscope etc.). 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 increase 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 determine the cause by visual inspection (incorrect installation, cracked 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 manufacturer of the complete product.

AV-20N83 AV-21D83

8. When service is required, observe the original lead dress. Extra precaution should be given to assure correct lead dress in the high voltage circuit area. Where a short circuit has occurred, those components that indicate evidence of overheating should be replaced. Always use the manufacturer's replacement components.

9. Isolation Check

(Safety for Electrical Shock Hazard)

After re-assembling the product, always perform an isolation check on the exposed metal parts of the cabinet (antenna terminals, video/ audio input and output terminals, Control knobs, metal cabinet, screw heads, earphone jack, control shafts, etc.) to be sure the product is safe to operate without danger of electrical shock.

(1) Dielectric Strength Test

The isolation between the AC primary circuit and all metal parts exposed to the user, particularly any exposed metal part having a return path to the chassis 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 appliance 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 service trade.

(2) Leakage Current Check

Plug the AC line cord directly into the AC outlet (do not use a line isolation transformer during this check.). Using a "Leakage Current Tester", 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 current must not exceed 0.5mA AC (r.m.s.). However, in tropical 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 voltmeter having 1000 ohms per volt or more sensitivity in the following manner. Connect a 1500Ø 10W resistor paralleled by a 0.15µF AC-type capacitor between an exposed 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 resistor. Now, reverse the plug in the AC outlet and repeat each measurement. Any voltage measured must not exceed 0.75V AC (r.m.s.). This corresponds to 0.5mA AC (r.m.s.). However, in tropical area, this must not exceed 0.3V AC (r.m.s.). This corresponds to 0.2mA AC (r.m.s.).

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 10kØ 2W resistor to the anode button.

No. 52076 3

AV-20N83 AV-21D83

FEATURES

s New chassis design enables use of an interactive on-screen control. s Pure flat CRT produces fine textured picture in every detail. s Wide range voltage (110V ~ 240V) for AC power input. s With AUDIO/VIDEO/COMPONENT input terminals.

C bus control utilizes single chip ICs.

s I s By means of AUTO PROGRAM, the TV stations can be selected

automatically and the TV channels can also be rearranged automatically.

s Built-in DIGITAL ECO MODE (ECONOMY, ECOLOGY).

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

s Built-in OFF TIMER & RETURN +.

MAIN DIFFERENCE LIST

Part Name

! MAIN PWB SCH-1090A-BK SCH-1122A-BK SCH-1315A-CK SCH-1316A-CK

FRONT CABINET LC10438-028A-H LC11129-024A-H LC11129-025A-HK LC10438-034A-HK

! REAR COVER GG10448-005A-H GG10130-001A-H LC10130-011A-HK LC10448-005A-HK

! PICTURE TUBE A48LWX10X A51LMV10X A51JSW51X07 A48JLL91X01

! DEG COIL QQW0156-001 QQW0157-001 QQW0156-001

! RATING LABEL GG20029-001A-H GG20016-025A-E GG20016-024A-E

REMOTE CONTROL UNIT RM-C1017-1H RM-C1027-1H

MODEL No.

AV-20N83

/BK AV-21D83/BK AV-21D83/VT AV-2 0N83/VT

4No. 52076

FUNCTIONS

a FRONT PANEL

AV-20N83 AV-21D83

[AV-20N83

/BK, AV-20N83/VT]

[AV-21D83/BK, AV-21D83/VT]

a REAR PANEL

L/MONO

IN (VIDEO-3)

L/MONO

IN (VIDEO-3)

COMPONENT

VIDEO-1

(

)

VIDEO-2

INPUT

MONO

RRC

OUTPUT

CHANNEL

VOLUME

EXIT

VOLUME

EXIT

SUB

POWER

SUB

POWER

a REMOTE CONTROL UNIT

RM-C1017-1H

[AV-20N83/BK, AV-21D83/BK]

MUTING

SYSTEM

COLOUR SOUND

DISPLAY

TV/VIDEO

OFF

TIMER

PICTURE

MODE

CHANNEL

RETURN+

SCAN

CHANNEL

PICTURE

POWER

BOOSTER

CINEMA

SURROUND

ECO

SENSOR

123

456

789

0-/

VOLUME

RM-C1017

RM-C1027-1H

[AV-21D83/VT, AV-20N83/VT]

PICTURE

MUTING

SYSTEM

COLOUR SOUND

DISPLAY

TV/VIDEO

OFF

TIMER

PICTURE

MODE

CHANNEL

RETURN+

SCAN

CHANNEL

POWER

BOOSTER

ECO

SENSOR

123

456

789

LUME

RM-C1027

No. 52076 5

AV-20N83

SPECIFIC SERVICE INSTRUCTIONS

DISASSEMBLY PROCEDURE [AV-20N83/BK, AV-20N83/VT]

REMOVING THE REAR COVER

1. Unplug the power supply cord.

2. Remove the 6 screws marked Å and 4 screws marked ı as shown in Fig.1.

3. Withdraw the Rear cover toward you.

[CAUTION]

When reinstalling the rear cover, carefully push it inward after in-

•

serting the Main PWB into the rear cover groove.

REMOVING THE MAIN PW BOARD

After removing the rear cover.

•

1. Slightly raise the both sides of the Main PWB by hand, take off the PB Stopper marked Ç from the front cabinet.

2. Withdraw the Main PWB backward. (If necessary, take off the wire clamp and connectors, etc.)

REMOVING THE SPEAKER [AV-20N83/BK]

After removing the rear cover.

•

1. Remove the 2 screws marked Î and 2 screws marked ´ as shown in Fig.1.

2. Follow the same steps when removing the other hand speaker.

REMOVING THE SPEAKER [AV-20N83/VT]

After removing the rear cover.

•

1. Remove the 2 screws marked Î as shown in Fig.1.

2. Follow the same steps when removing the other hand speaker.

CHECKING THE MAIN PW BOARD

1. To check the back side of the Main PWB.

1) Pull out the Main PWB. (Refer to REMOVING THE MAIN PW

BOARD).

2) Erect the Main PWB vertically so that you can easily check its

back side.

[CAUTION]

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

•

other connectors are properly connected. When repairing, connect the Deg. coil to the DEG. connector on the

•

Main PWB.

WIRE CLAMPING AND CABLE TYING

1. Be sure to clamp the wire.

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

6No. 52076

FRONT CABINET

PICTURE TUBE

SPEAKER

MAIN PWB (CRT SOCKET PWB)

MAIN PWB

AV-20N83

(X2)

SPEAKER

(X2)

REAR COVER

(X6)

Fig.1

No. 52076 7

AV-21D83

DISASSEMBLY PROCEDURE [AV-21D83/BK, AV-21D83/VT]

REMOVING THE REAR COVER

1. Unplug the power supply cord.

2. Remove the 7 screws marked in Fig.1.

3. Withdraw the Rear cover toward you.

[CAUTION]

When reinstalling the rear cover, carefully push it inward after in-

•

serting the Main PWB into the rear cover groove.

REMOVING THE MAIN PW BOARD

After removing the rear cover.

•

1. Slightly raise the both sides of the Main PWB by hand, take off the PB Stopper marked

2. Withdraw the Main PWB backward. (If necessary, take off the wire clamp and connectors, etc.)

from the front cabinet.

and 4 screws marked ı as shown

REMOVING THE SPEAKER [AV-21D83/BK]

After removing the rear cover.

•

1. Remove the 2 screws marked Î as shown in Fig.1.

2. Follow the same steps when removing the other hand speaker.

REMOVING THE SPEAKER [AV-21D83/VT]

After removing the rear cover.

•

1. Remove the 2 screws marked Î and 2 screws marked ´ as shown in Fig.1.

2. Follow the same steps when removing the other hand speaker.

CHECKING THE MAIN PW BOARD

1. To check the back side of the Main PWB.

1) Pull out the Main PWB. (Refer to REMOVING THE MAIN PW

BOARD).

2) Erect the Main PWB vertically so that you can easily check its

back side.

[CAUTION]

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

•

other connectors are properly connected. When repairing, connect the Deg. coil to the DEG. connector on the

•

Main PWB.

WIRE CLAMPING AND CABLE TYING

1. Be sure to clamp the wire.

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

8No. 52076

FRONT CABINET

PICTURE TUBE

MAIN PWB (CRT SOCKET PWB)

MAIN PWB

SPEAKER

REAR COVER

(X2)

B (X4)

(X7)

(X2)

AV-21D83

Fig.1

No. 52076 9

AV-20N83 AV-21D83

REMOVING THE CRT

* Replacement of the CRT should be performed by 2 or more persons.

After removing the rear cover, chassis etc.,

•

1. Putting the CRT change table on soft cloth, the CRT change table

should also be covered with such soft cloth (shown in Fig. 2).

2. While keeping the surface of CRT down, mount the TV set on the

CRT change table balanced will as shown in Fig. 3.

3. Remove 4 screws marked by arrows with a box type screwdriver as

shown in Fig. 3. Since the cabinet will drop when screws have been removed, be sure

•

to support the cabinet with hands.

4. After 4 screws have been removed, put the cabinet slowly on cloth

(At this time, be carefully so as not to damage the front surface of the cabinet) shown in Fig. 4. The CRT should be assembled according to the opposite sequence

•

of its dismounting steps.

* The CRT change table should preferably be smaller that the CRT sur-

face, and its height be about 35cm.

CRT CHANGE TABLE

CLOTH

CRT CHANGE TABLE

Fig. 2

CRT

APPROX. 35cm

BOX TYPE SCREW DRIVER

COATING OF SILICON GREASE FOR ELECTRICAL INSULATION ON THE CRT ANODE CAP SECTION.

Subsequent to replacement of the CRT and HV transformer or repair

•

of the anode cap, etc. by dismounting them, be sure to coat silicon grease for electrical insulation as shown in Fig. 5.

1. Wipe around the anode button with clean and dry cloth. (Fig. 5)

2. Coat silicon grease on the section around the anode button. At this

time, take care so that any silicon greases does not sticks to the anode button. (Fig. 6)

夝 Silicon grease product No. KS - 650N

CRT

Anode button

CABINET

Approx. 20mm (Do not coat grease on this section

Fig. 3

CRT

CRT CHANGE TABLE

Fig. 4

Silicon grease should be coated by 5mm or more from the outside diameter of anode cap.

Silicon grease

coating

Fig. 5

10 No. 52076

Anode button (No sticking of silicon grease)

Coating position of silicon grease

Anode cap

Fig. 6

REPLACEMENT OF MEMORY IC

1. MEMORY IC

This TV uses the following memory IC.

Memory IC: IC1702 on MAIN PW Board

The memory IC memorizes data for correctly operating the video and deflection circuits. When replacing the memory IC, be sure to use the same type IC written with the initial values of data. In other words, use the specific IC listed in “PRINTED WIRING BOARD PA RTS LIST”. For its mounting location, refer to “ADJUSTMENT LOCATIONS”.

AV-20N83 AV-21D83

(6) User setting

Check the user setting values in Table 2, and if setting value is different, set the correct value. For setting, refer to the OPERATING INSTRUCTIONS.

(7) Setting of SERVICE MENU

Ver ify the setting for each setting item in the SERVICE MENU.(See Ta ble 3.) If readjustment is necessary, perform adjustment referring to “SERVICE ADJUSTMENTS”.

2. PROCEDURE FOR REPLACING MEMORY IC

(1) Power off

Switch the power off and unplug the power cord from the wall outlet.

(2) Replacing the memory IC

Replace the memory IC with new one. Be sure to use the memory IC written with the initial data values.

(3) Power on

Plug the power cord into the wall outlet and switch the power on.

(4) Check and setting of SYSTEM CONSTANT SET:

1) Press the DISPLAY key and the PICTURE MODE key on the remote control unit simultaneously. The SERVICE MENU screen will be displayed.(See Fig.1.)

2) In the SERVICE MENU, press the DISPLAY key and PICTURE MODE key simultaneously. Then, the SYSTEM CONSTANT SET screen will be displayed.(See Fig.2.)

3) Check whether the setting values of the SYSTEM CONSTANT SET are the same as those indicated in Table1. If the value is different, select the setting item with the MENU &/^ key, and set the correct value with the MENU */T key.

4) Press the DISPLAY key twice to return to the normal screen.

(5) Receive channel setting

Refer to the OPERATING INSTRUCTIONS and set the receive channels (channels preset).

NAME OF REMOTE CONTROL KEYS

SERVICE MENU

1. IF

3. DEF

5. PRESET

6. PLUG & PLAY (ON)

1-6 : SELECT DISPLAY : EXIT

******* **** ***** ***** **** **** *** ***

2. VC

4. VSM PRESET

Fig. 1

SYSTEM CONSTANT-

SYSTEM CONSTANT SET 1

SYSTEM COMB TILT TEXT SUPER BASS LANGUAGE

>? : SEL -+ : OPE

SYSTEM CONSTANT-

SYSTEM CONSTANT SET 2

MSP BILINGUAL B / B SOUND TUNER COLOUR AUTO

>? : SEL -+ : OPE

DISP : EXIT

MULTI NO NO NO NO E/R/C/M/I

YES NO NO MU NO

DISPLAY

PICTURE MODE

PICTURE BOOSTER

MUTING

SYSTEM

COLOUR SOUND

DISPLAY

I/II

TV/VIDEO

OFF

TIMER

PICTURE

MODE

CHANNEL

RETURN+

SCAN

CHANNEL

HOLD

REVEAL

SUBPAGE CANCEL

STORE MODE

POWER

CINEMA

SURROUND

ECO

SENSOR

TV/TEXT

123

456

789

0-/

VOLUME

TEXT

SIZE

INDEX

RM-C1010

SYSTEM CONSTANT-

SYSTEM CONSTANT SET 3

LOCK 1 MHz

>? : SEL -+ : OPE

500 KHz 250 KHz

156. 25 KHz

31.25 KHz

SYSTEM CONSTANT-

SYSTEM CONSTANT SET 4

3D SURROUND 3CH VOL/TONE AMP TUNER

>? : SEL -+ : OPE

: 040 : 040 : 040 : 030 : 030

DISP : EXIT

NO NO NO

DISP : EXIT

III

Fig. 2

No. 52076 11

AV-20N83 AV-21D83

SETTING OF SYSTEM CONSTANT SET

Setting item Setting content

SYSTEM

COMB

TILT

TEXT

SUPER BASS

LANGUAGE

MSP

BILINGUAL

B/B SOUND

TUNER

COLOUR AUTO

LOCK 1MHz

500KHz

MULTI TRIPLE PAL SINGLE VIET

YES NO

EASTERN UKRANIAN RUSSIAN NO PAN EURO ARABK

YES NO

E/ T E/V E

YES NO

MU MA

YES NO

000 240

Setting value

AV-20N83

/BK

AV-21D83

/BK

AV-21D83

SINGLE VIET

E/T

YES

040

E/V

/VT

AV-20N83

/VT

250KHz

156.25KHz

31.25KHz

3D SURROUND

3CH VOL/TONE

AMP TUNER

000 240

YES NO

Table 1

040

030

YES

12 No. 52076

USER SETTING VALUES

Setting item Setting value

SUB POWER ON

CHANNEL POSITION 1 POSITION

CHANNEL PRESET REFER TO OPERATING INSTRUCTIONS

VOLUME 15 ± 2

TV/VIDEO TV

VNR OFF

COMPRESS (16:9) OFF

AUTO SHUTOFF OFF

CHILD LOCK OFF

BLUE BACK ON

VIDEO-2 SET VIDEO

LANGUAGE THAI [AV-20N83

VIET [AV-21D83/VT, AV-20N83/VT only]

3D SURROUND OFF

AI VOLUME ON

ON SCREEN DISPLAY POSITION INDICATION

COLOUR SYSTEM PAL

SOUND SYSTEM B/G

PICTURE MODE-VSM BRIGHT

OFF TIMER 00

ECO SENSOR OFF

BASS CENTRE

TREBLE CENTRE

BALANCE CENTRE

BILINGUAL MODE 1/2 [AV-20N83/BK, AV-21D83/BK only]

/BK, AV-21D83/BK only]

AV-20N83 AV-21D83

Tab le 2

No. 52076 13

AV-20N83 AV-21D83

SERVICE MENU SETTING ITEMS

Service menu Setting item

1. IF 1. VCO

2. DELAY POINT

2. VC 1. CUTOFF(R/G)

2. DRIVE(R/G/B)

3. BRIGHT

4. CONT

5. COLOUR

6. TINT

7. SHARP

8. YDELAY

9. AMP T. SHARP

3. DEF 1. VER. SLOPE

2. VER. HEIGHT

3. VER. POSITION

4. VER. SCURVE

5. HOR. POSITION

6. HOR. WIDTH

7. EW-PIN

8. EW-TRAPEZ

9. UP CORNER

10. DW CORNER

11. HOR. PARALL

12. HOR. BOW

13. V. ZOOM

4. VSM PRESET 1. TINT

(BRIGHT/STD/SOFT) 2. COLOUR

Do not adjust

3. BRIGHT

4. CONT

5. SHARP

Do not adjust

Service menu Setting item

5. PRESET 1. PSNS

Do not adjust

PLUG & PLAY(ON)

2. ACL

3. MUS

4. MAT

5. FCO

6. BPS

7. IFLH

8. VID

9. STM

10. AFCW

11. VSW

12. FFI

13. AGC

14. CL

15. AKB

16. HBL

17. BKS

18. READ STATUS

19. VNR

20. PEAK

21. IVG

22. WPL

23. SOFT CLIPPER

24. IF PLL OFFSET

25. OVERSHOOT

26. HCO

27. HP2

28. AI VOLUME ADN

29. SUB BASS 3D

30. SUB TREBLE 3D

31. CCCLOOP

Table 3

14 No. 52076

Do not adjust

REPLACEMENT OF CHIP COMPONENT

CAUTIONS

1. Avoid heating for more than 3 seconds.

2. Do not rub the electrodes and the resist parts of the pattern.

3. When removing a chip part, melt the solder adequately.

4. Do not reuse a chip part after removing it.

SOLDERING IRON

1. Use a high insulation soldering iron with a thin pointed end of it.

2. A 30w soldering iron is recommended for easily removing parts.

REPLACEMENT STEPS

1. How to remove Chip parts

Resistors, capacitors, etc.

(1) As shown in the figure, push the part with tweezers and alter-

nately melt the solder at each end.

AV-20N83 AV-21D83

2. How to install Chip parts

Resistors, capacitors, etc.

(1) Apply solder to the pattern as indicated in the figure.

(2) Shift with tweezers and remove the chip part.

Transistors, diodes, variable resistors, etc.

(1) Apply extra solder to each lead.

SOLDER

(2) As shown in the figure, push the part with tweezers and alter-

nately melt the solder at each lead. Shift and remove the chip part.

SOLDER

(2) Grasp the chip part with tweezers and place it on the solder.

Then heat and melt the solder at both ends of the chip part.

Transistors, diodes, variable resistors, etc. (1) Apply solder to the pattern as indicated in the figure. (2) Grasp the chip part with tweezers and place it on the solder. (3) First solder lead A as indicated in the figure.

(4) Then solder leads B and C.

Note : After removing the part, remove remaining solder from the

pattern.

No. 52076 15

AV-20N83 AV-21D83

SERVICE ADJUSTMENTS

ADJUSTMENT PREPARATION

1. You can make the necessary adjustments for this unit with either the remote control unit or with the adjustment equipment and parts as given below.

2. Adjustment with the remote control unit is made on the basis of the initial setting values, however, the new setting values which set the screen to its optimum condition may differ from the initial settings.

3. Make sure that AC power is turned on correctly.

4. Turn on the power for the set and test equipment before use, and start the adjustment procedures after waiting at least 30 minutes.

5. Unless otherwise specified, prepare the most suitable reception or input signal for adjustment.

6. Never touch any adjustment parts, which are not specified in the list for this adjustment-variable resistors, transformers, capacitors, etc.

7. Presetting before adjustment. Unless otherwise specified in the adjustment instructions, preset the following functions with the remote control unit.

User mode setting position

•

Setting item Setting value

PICTURE MODE(VSM) BRIGHT

VNR OFF

BASS, TREBLE, BALANCE CENTRE

TINT, COLOUR, BRIGHT, SHARP

CONTRAST MAXIMUM

CENTRE

MEASURING INSTRUMENT

1. DC voltmeter (or Digital voltmeter)

2. Oscilloscope

3. Signal generator (Pattern generator) [PAL/SECAM/NTSC]

4. Remote control unit

ADJUSTMENT ITEMS

B1 POWER SUPPLY

•

FOCUS ADJUSTMENT

•

IF CIRCUIT ADJUSTMENTS

•

Adjustment of VCO (CW) Adjustment of DELAY POINT (AGC TAKE-OVER)

VC (VIDEO/CHROMA) CIRCUIT ADJUSTMENTS

•

Adjustment of WHITE BALANCE (Low light) Adjustment of WHITE BALANCE (High light) Adjustment of SUB BRIGHT Adjustment of SUB CONTRAST Adjustment of SUB COLOUR-Ι Adjustment of SUB COLOUR-ΙΙ Adjustment of SUB TINT-Ι Adjustment of SUB TINT-ΙΙ

DEFLECTION CIRCUIT ADJUSTMENTS

•

Adjustment of V. SLOPE Adjustment of V. POSITION Adjustment of V. HEIGHT Adjustment of H. POSITION Adjustment of H. WIDTH Adjustment of SIDE PIN Adjustment of TRAPEZIUM Adjustment of V. S-CURVE Adjustment of CORNER Adjustment of H. PARALLEL Adjustment of H. BOW

VSM PRESET SETTING

•

PRESET SETTING

•

PURITY ADJUSTMENT

•

CONVERGENCE ADJUSTMENTS

•

Adjustment of STATIC CONVERGENCE Adjustment of DYNAMIC CONVERGENCE

16 No. 52076

ADJUSTMENT LOCATIONS

AV-20N83 AV-21D83

MAIN PWB ASS'Y

POWER SW

S901

DEG

IC702

S783 S781

S784 S782 S780

IC701

J804J801 J802 J803

J773

J772 J771

J770

CN001

GND B1

S780 : MENU S781 : CH– S782 : CH+ S783 : VOL– S784 : VOL+

FRONT

HVT

AV IN/OUT

MAIN PWB ASS'Y

(CRT SOCKET)

(SOLDER SIDE)

TU001

TP-E

TP-47G

CRT EARTH

(BRAIDED ASS'Y)

UPPER : FOCUS (F1)

LOWER : SCREEN

TOP

No. 52076 17

AV-20N83 AV-21D83

BASIC OPERATION IN SERVICE MENU

1. TOOL OF SERVICE MENU OPERATION

Operate the SERVICE MENU with the remote control unit.

2. SERVICE MENU ITEMS

With the SERVICE MENU,various settings (adjustments)can be made,and they are broadly classified in the following items of settings:

1.IF ......................................For entering/adjusting the setting values (adjustment values)of the IF circuit.

•

2.VC ....................................For entering/adjusting the setting values (adjustment values)of the VIDEO/CHROMA circuit.

•

3.DEF ..................................For entering/adjusting the setting values (adjustment values)of the DEFLECTION circuit.

•

4.VSM PRESET ..................For setting the values of STANDARD,SOFT and BRIGHT.

•

5.PRESET ........................... For setting the values of the preset.

•

6.PLUG & PLAY (ON) ......... This is not used for service.

•

3. BASIC OPERATION IN SERVICE MENU

(1) How to enter SERVICE MENU

Press the DISPLAY key and the PICTURE MODE key on the remote control unit simultaneously. The SERVICE MENU screen will be displayed. (See Fig. 1 on the next page.)

(2) Selection of SUB MENU SCREEN

Press one of the keys 1 to 6 on the remote control unit,and select the SUB MENU SCREEN from the SERVICE MENU.(See Fig.1 on the next page.)

(VSM:video status memory)

SERVICE MENU → SUB MENU 1. IF

2. VC

3. DEF

4. VSM PRESET

5. PRESET

6. PLUG & PLAY (ON)

(3) Method of Setting

*Once the setting values are set,they are memorized automatically. *It must not adjust without inputting a signal.

1) 1. IF

[1.VCO ]

(a) 1 Key......................... Select 1. IF.

(b) 1 Key......................... Select 1. VCO.

Under normal conditions, no adjustment is required.

[2.DELAY POINT ]

(a) 1 Key......................... Select 1. IF.

(b) 2 Key......................... Select 2.DELAY POINT.

(d) DISPLAY Key ............ When this is pressed twice, you will return to the SERVICE MENU.

2) 2. VC, 3. DEF, 4. VSM PRESET and 5. PRESET

(a) 2 ~5 Keys.................. Select one from 2. VC, 3. DEF, 4. VSM PRESET and 5. PRESET

(b) MENU &/^ key........ Select setting items.

(d) DISPLAY Key ............ When this is pressed, you will return to the SERVICE MENU.

*/T

Key ........ Adjust the setting value.

*/T

Key ........ Adjust the setting values of the setting items.

•

Use the number keys on the remote control unit for setting of WHITE BALANCE.

•

For the setting, refer to each item concerned.

3) 6. PLUG & PLAY (ON)

This is not used for service.

(4) Release of SERVICE MENU

After completing the setting, return to the SERVICE MENU by pressing the DISPLAY key, then again press the DISPLAY key to return to the normal screen.

18 No. 52076

AV-20N83 AV-21D83

SERVICE MENU

1. IF

3. DEF

5. PRESET

6. PLUG & PLAY (ON)

1-6 : SELECT DISPLAY : EXIT

******* **** ***** ***** **** **** *** ***

2. VC

4. VSM PRESET

SUB MENU 1. IF

1. VCO

2. DELAY POINT

1-2 : SELECT DISPLAY : EXIT

SUB MENU 2. VC

V/C

PAL

1. CUTOFF

50 Hz

MENU 89: SELECT

(R) (G)

/+: OPERATE

** **

DISPLAY : EXIT

Setting item

1. CUTOFF (R/G)

2. DRIVE (R/G/B)

3. BRIGHT

4. CONT

5. COLOUR

6. TINT

7. SHARP

8. YDELAY

9. AMP T.SHARP

VCO (CW)

TOO HIGH ABOVE REFERENCE BELOW REFERENCE TOO LOW

DELAY POINT VHF

AGC TAKE-OVER

/+: OPERATE

MHz

*****

DISPLAY : EXIT

SUB MENU 5. PRESET

PRESET 50Hz

1. PSNS

MENU 89: SELECT

/+: OPERATE

DISPLAY : EXIT

SUB MENU 3. DEF

4 : 3 / 16 : 9

DEF 4 : 3

1. VER. SLOPE

50Hz

MENU 89: SELECT

/+: OPERATE

PAL

DISPLAY : EXIT

1. VER. SLOPE

2. VER. HEIGHT

3. VER. POSITION

4. VER. SCURVE

5. HOR. POSITION

6. HOR. WIDTH

Setting item

7. EW-PIN

8. EW-TRAPEZ

9. UP CORNER

10. DW CORNER

11. HOR. PARALL

12. HOR. BOW

13. V. ZOOM

SUB MENU 4. VSM PRESET

BRIGHT / STD / SOFT

STANDARD

TINT COLOUR BRIGHT CONT SHARP

MENU 89: SELECT

/+: OPERATE

PALB/G

1. PSNS

2. ACL

3. MUS

4. MAT

5. FCO

6. BPS

7. IFLH

8. VID

9. STM

10. AFCW

11. VSW

12. FFI

13. AGC

14. CL

15. AKB

16. HBL

17. BKS

18. READ STATUS

** ** ** ** **

DISPLAY : EXIT

Setting item

19. VNR

20. PEAK

21. IVG

22. WPL

23. SOFT CLIPPER

24. IF PLL OFFSET

25. OVERSHOOT

26. HCO

27. HP2

Setting item

1. TINT

2. COLOUR

3. BRIGHT

CONT

5. SHARP

28. AI VOLUME ADN

29. SUB BASS 3D

30. SUB TREBLE 3D

31. CCCLOOP

Fig. 1

No. 52076 19

AV-20N83 AV-21D83

ADJUSTMENTS

B1 POWER SUPPLY

Item

Measuring instrument

Test point Adjustment part Description

Check of B1 POWER

Signal generator

SUPPLY

DC voltmeter

FOCUS ADJUSTMENT

Item

Adjustment of FOCUS

Measuring instrument

Signal generator

B1 (pin 1) GND (pin 5) [CN00S connector

1. Receive a black and white signal.

2. Connect a DC voltmeter between B1 and GND (between pin 1 and 5 of the connector CN00S).

3. Make sure that the voltage is DC115 ± 1.5V.

in MAIN PWB]

Test point Adjustment part Description

FOCUS VR [In HVT]

Notes:

• Set PICTURE MODE (VSM) to “BRIGHT”.

• The final adjustment of CONVERGENCE must be done after the

FOCUS adjustment. (CONVERGENCE is changed by FOCUS adjustment.) When makes difference by FOCUS adjustment, should be reconfirming PURITY adjustment.

1. Receive a cross-hatch signal.

2. While looking at the screen centre, adjust the FOCUS VR so that the vertical and horizontal lines will be clear and in fine detail.

3. Make sure that the picture is in focus even when the screen gets darkened.

IF CIRCUIT ADJUSTMENTS

Item

Adjustment of VCO (CW)

Adjustment of DELAY POINT (AGC TAKE-OVER)

DELAY POINT (AGC TAKE-OVER)

Measuring instrument

Remote control unit

VCO (CW)

TOO HIGH ABOVE REFERENCE BELOW REFERENCE TOO LOW

Remote control unit

Setting

(Adjustment time)

Test point Adjustment part Description

. MHz

DISPLAY : EXIT

VCO (CW)

YELLOW

DELAY POINT

Initial setting value

Note:

• Under normal conditions, no adjustment is required.

1. Select 1. IF from the SERVICE MENU.

2. Select 1. VCO by pressing the 1 key on the remote control unit.

3. Receive a broadcast signal.

4. Check the characters colour of the BELOW REFERENCE displayed to yellow.

5. Press the DISPLAY key three times to return to normal screen.

1. Receive a black and white broadcast signal (colour off).

2. Select 1. IF from the SERVICE MENU.

3. Select 2. DELAY POINT by pressing the 2 key on the remote con- trol unit.

4. Adjust the MENU */T key in order to eliminate any noise or beat from the image. Any increase above the initial value produces noise and any decrease below it produces beat.

5. Press the DISPLAY key three times to return to the normal screen.

6. Turn to other channels and make sure that there are no irregularities.

20 No. 52076

VC (VIDEO/CHROMA) CIRCUIT ADJUSTMENTS

The setting (adjustment) using the remote control unit is made on the basis of the initial setting values. The setting values which adjust the screen to the optimum condition can be different from the initial setting values.

Do not change the initial setting values of the setting (adjustment) items not listed in “ADJUSTMENT”.

•

[SUB MENU 2. VC] : Do not adjust.

Setting (Adjustment)

item

Variable range

PAL SECAM NTSC3.58 NTSC4.43 COMPONENT (V-2)

1 CUT-OFF (R/G) -32 – +31 0/0

2 DRIVE (R/G/B) -32 – +31 0/0/0

3 BRIGHT (TV/V-1/V-2/V-3) -32 – +31 -18/-1/-1/-1 —/—/-2/—

4 CONT -32 – +31 -20 —

5 COLOUR -32 – +31 -5 -3 -12 -2 +10

TINT (TV/VIDEO) *1 — — -15/+2 +1/+1 —

TINT (TV/VIDEO) *2

SHARP (TV/VIDEO) *3 -15/+5

SHARP (TV/VIDEO) *4

-32 – +31 ——-15/-4 +1/+1 —

-32 – +31

-10/+5 —/0

8Y DELAY (TV/VIDEO) -8 – +7 -7/+1 +5/+1 0/+1 -7/0 —

9 AMP T. SHARP -32 – +31 0

Initial setting value

—/0

AV-20N83 AV-21D83

*1: AV-20N83/BK, AV-21D83/VT, AV-20N83/VT *2: AV-21D83/BK *3: AV-20N83/BK, AV-21D83/BK, AV-20N83/VT *4: AV-21D83/VT

Item

Adjustment of WHITE

Measuring instrument

Signal generator

Test point Adjustment part Description

1. CUTOFF (R)

CUTOFF (G)

Note:

• Set PICTURE MODE (VSM) to “BRIGHT”.

BALANCE (Low light)

Remote control unit

SCREEN VR [In HVT]

1. Receive a PAL black and white signal (colour off).

2. Select 2. VC from the SERVICE MENU.

3. Select 1. CUTOFF (R) and (G) with MENU &/^ key, and set each

value to initial setting value with the 4 and 7 keys, or 5 and 8 keys on

V/C

1. CUTOFF

50 Hz

MENU 89: SELECT

(R) (G)

/+: OPERATE

PAL

** **

DISPLAY : EXIT

the remote control unit.

4. Press the 1 key on the remote control unit to produce a single hori- zontal line.

5. Tu rn the SCREEN VR fully counterclockwise, then slowly turn it clockwise to where a red, blue or green colour is faintly visible.

6. Use the keys 4 and 7 or 5 and 8 on the remote control unit and adjust the other 2 colours to where the single horizontal line appears white.

7. Tu rn the SCREEN VR to where the single horizontal line glows faintly.

8. Press the 2 key to return to 1. CUTOFF screen.

9. Press the DISPLAY key twice to return to the normal screen.

Setting (Adjustment) Variable Initial setting

Item range value

1. CUT OFF

R –32 — +31 0

G –32 — +31 0

H.LINE OFF

H.LINE ON

R. CUTOFF (

REMOTE CONTROL UNIT

12 3

)

G. CUTOFF (8)

R. CUTOFF (

789

)

G.CUTOFF (

)

No. 52076 21

AV-20N83 AV-21D83

Item

Adjustment of WHITE BALANCE (High light)

R. DRIVE (

Measuring instrument

Signal generator

Test point Adjustment part Description

2. DRIVE (R) DRIVE (G) DRIVE (B)

Remote control unit

V/C

/+: OPERATE

(R) (G) (B)

2. DRIVE

50 Hz

MENU 89: SELECT

PAL

** ** **

DISPLAY : EXIT

REMOTE CONTROL UNIT

12 3

) B. DRIVE (8)

G. DRIVE (8)

Notes:

• Proceed to the following adjustment after having completed the adjustment of LOW LIGHT WHITE BALANCE.

• Set PICTURE MODE (VSM) to “BRIGHT”.

1. Receive a PAL black and white signal (colour off).

2. Select 2. VC from the SERVICE MENU.

3. Select 2. DRIVE (R), (G) and (B) with MENU &/^ key, and set

each value to initial setting value with the 4 to 9 keys on the remote control unit.

4. Use the keys 4 to 9 to produce a white screen.

5. Press the DISPLAY key twice to return to the normal screen.

Setting (Adjustment) Variable Initial setting

Item range value

R –32 — +31 0

2. DRIVE G –32 — +31 0

B –32 — +31 0

R. DRIVE (

Adjustment of SUB BRIGHT

Adjustment of SUB CONTRAST

789

)

Remote control unit

B. DRIVE (

G.DRIVE (

3. BRIGHT

4. CONT

)

Notes:

• Proceed to the following adjustment after having completed the adjustments of LOW LIGHT WHITE BALANCE and HIGH LIGHT WHITE BALANCE.

• Set PICTURE MODE (VSM) to “BRIGHT”.

1. Receive a broadcast.

2. Select 2. VC from the SERVICE MENU.

3. Select 3. BRIGHT with the MENU &/^ key.

4. Set the initial setting value with the MENU */T key.

5. If the brightness is not best with the initial setting value, make fine

adjustment until you get the best brightness.

6. Press the DISPLAY key twice to return to the normal screen.

Notes:

• Proceed to the following adjustment after having completed the adjustment of SUB BRIGHT.

• Set PICTURE MODE (VSM) to “BRIGHT”.

1. Receive a broadcast.

2. Select 2. VC from the SERVICE MENU.

3. Select 4. CONT with the MENU &/^ key.

4. Set the initial setting value with the MENU */T key.

5. If the contrast is not best with the initial setting value, make fine

6. Press the DISPLAY key twice to return to the normal screen.

22 No. 52076

adjustment until you get the best contrast.

AV-20N83 AV-21D83

Item

Adjustment of SUB COLOUR-I

Measuring instrument

Remote control unit

Test point Adjustment part Description

5. COLOUR

[Method of adjustment without measuring instrument]

Notes:

• Proceed to the following adjustment after having completed the adjustment of SUB CONT.

• Set PICTURE MODE (VSM) to “BRIGHT”.

– PAL COLOUR –

1. Receive a PAL broadcast.

2. Select 2. VC from the SERVICE MENU.

3. Select 5. COLOUR with the MENU &/^ key.

4. Set the initial setting value for PAL COLOUR with the MENU */Tkey.

5. If the colour is not best with the initial setting value, make fine adjustment until you get the best colour.

6. Press the DISPLAY key twice to return to the normal screen.

– SECAM COLOUR –

7. Receive a SECAM broadcast.

8. Press the COLOUR SYSTEM button on the remote control unit to select the SECAM colour system.

9. Make fine adjustment of SECAM COLOUR in the same way as for “PAL COLOUR”.

– NTSC 3.58 COLOUR –

10. Receive a NTSC 3.58MHz broadcast.

11. Press the COLOUR SYSTEM button on the remote control unit to

select the NTSC 3.58 colour system.

12. Make similar fine adjustment of NTSC 3.58 COLOUR in the same

way as for “PAL COLOUR”.

– NTSC 4.43 COLOUR –

When adjustment is done for NTSC 3.58 COLOUR, appropriate values are automatically set for NTSC 4.43 COLOUR.

Adjustment of SUB COLOUR-II

Signal generator

Oscilloscope

TP-47G TP-E (H) [MAIN PWB (CRT

SOCKET)] Remote control unit

(A)

A (V

PA L SECAM

AV-20N83/BK, AV-20N83/VT +8V +6V -12V

AV-21D83/BK, AV-21D83/VT +11V +13V +2V

Tab le 1

5. COLOUR [Method of adjustment using measuring instrument]

Notes:

• Proceed to the following adjustment after having completed the adjustment of SUB CONT.

• Set PICTURE MODE (VSM) to “BRIGHT”.

– PAL COLOUR –

1. Receive a PAL colour bar signal (full field colour bar 75% white).

2. Select 2. VC from the SERVICE MENU.

3. Select 5. COLOUR with the MENU &/^ key.

Set the initial setting value of PAL COLOUR with the MENU */Tkey.

5. Connect the oscilloscope between TP-47G and TP-E.

Adjust PAL COLOUR to set the value (A) in the figure to voltage as shown in Table 1.

– SECAM COLOUR –

7. Receive a SECAM colour bar signal (full field colour bar 75% white).

(–) 0V (+)

8. Press the COLOUR SYSTEM button on the remote control unit to select the SECAM colour system.

Set the initial setting value of SECAM COLOUR with the MENU */Tkey.

10. Adjust SECAM COLOUR to set the value (A) in the figure to

age as shown in Table 1.

– NTSC 3.58 COLOUR –

11. Receive a NTSC 3.58 colour bar signal (full field colour bar 75% white).

W-G

)

NTSC3.58

12. Press the COLOUR SYSTEM button on the remote control unit to

select the NTSC 3.58 colour system.

13. Set the initial setting value of NTSC 3.58 COLOUR with the MENU

*/T

key.

14. Adjust NTSC 3.58 COLOUR to set the value (A) in the figure to

voltage as shown in Table 1.

– NTSC 4.43 COLOUR –

When adjustment is done for NTSC 3.58 COLOUR, appropriate values are automatically set for NTSC 4.43 COLOUR.

volt-

No. 52076 23

+ 52 hidden pages

JVC AV-20N83, AV-21D83 Schematic

CONTENTS

SPECIFICATIONS

SAFETY PRECAUTIONS

FEATURES

FUNCTIONS

SPECIFIC SERVICE INSTRUCTIONS

SERVICE ADJUSTMENTS