JVC AV-2937V1/E, AV-29VX71/G, AV-29VX71/S Service Manual

SERVICE MANUAL

FLAT COLOUR TELEVISION

BASIC CHASSIS

CH3

RM-C1302

AV-29VX71 AV-29VX71 AV-2937V1

1 PRECAUTION ......................................................................................................................................................... 1-3

2 SPECIFIC SERVICE INSTRUCTIONS ................................................................................................................... 1-4

3 DISASSEMBLY ....................................................................................................................................................... 1- 6

4 ADJUSTMENT ...................................................................................................................................................... 1-13

5 TROUBLESHOOTING ........................................................................................................................................... 1-31

No.52192

2003/8

SPECIFICATION

Items

Dimensions (W × H × D)

Mass 43.5kg

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

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

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

Stereo System Playback only

Teletext system FLOF (Fastext), WST (World Standard Text)

Receiving Frequency VHF Low 46.25MHz – 140.25MHz (AS0 – S6)

VHF High 147.25MHz – 423.25MHz (S7 – S36)

Intermediate VIF 38.0MHz

Frequency SIF 31.5MHz (6.5MHz), 32.0MHz (6.0MHz), 32.5MHz (5.5MHz), 33.5MHz (4.5MHz)

Colour Sub Carrier Frequency 4.43MHz (PAL), 4.40MHz/4.25MHz (SECAM), 3.58MHz/4.43MHz (NTSC)

Aerial Input Terminal 75Ω unbalanced

Power Input AC110V – AC240V, 50Hz / 60Hz

Power Consumption 190W

Picture Tube Visible size : 67.6cm (Diagonal) / 54.1cm x 40.6cm (H x V)

High Voltage 32kV -1.5kV / +1.0kV (at zero beam current)

Speaker 6.5cm × 13cm, Oval type × 2

Audio Output 10W + 10W

Video / Audio Input S-Video (1) Mini-DIN 4 pin × 1

(1 / 2 / 3) Y : 1V(p-p), positive (negative sync provided), 75Ω

Video (1/2/3) 1V(p-p), negative sync, 75Ω, RCA pin jack × 3

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

Component (2) RCA pin jack × 3

Video / Audio Output Video 1V(p-p), 75Ω, RCA pin jack × 1

Headphone 3.5mm stereo mini jack × 1

Remote Control Unit RM-C1302-1H

81.2cm x 58.4cm x 52.0cm

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

CATV Mid : X-Z, S1-S10

Super : S11-S20

Hyper : S21-S41

(Max.)

/ 145W

C : 0.286V(p-p) (Burst signal), 75Ω

Y : 1V(p-p), positive (negative sync), 75Ω

CB/CR : 0.7V(p-p), 75Ω

Audio

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

(AA/R06/UM-3 battery × 2)

(Avg.)

Contents

Design & specifications are subject to change without notice.

1-2 (No. 52192)

SECTION 1

PRECAUTION

1. 1 SAFETY PRECAUTIONS

(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 (

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

(NEUTRAL) 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 : ( GND, the ISOLATED (NEUTRAL) : ( EARTH : ( 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.

(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 10k 2W resistor to the anode button.

!) on the parts list in Service manual.

) side

) side GND and

) side GND. Don't short between the LIVE

(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.

a) 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.

b) 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 1500

Ω 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.).

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

0.15µF AC-TYPE

PLACE THIS PROBE

1500Ω 10W

Ω

GOOD EARTH GROUND

ON EACH EXPOSE ME TAL PA RT

(No. 52192) 1-3

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

2. 1 FEATURES

• New chassis design enables use of an interactive on-screen control.

• Pure flat CRT produces fine textured picture in every detail.

• Wide range voltage (110V ~ 240V) for AC power input.

• With AUDIO/VIDEO/S-VIDEO/COMPONENT input terminals.

• I

C bus control utilizes single chip ICs.

• Adoption of the Picture-In-Picture (PIP) function.

• By means of AUTO PROGRAM, the TV stations can be selected automatically and the TV channels can also be rearranged

automatically.

• 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.

• Built-in OFF TIMER & RETURN +.

2. 2 MAIN DIFFERENCE LIST

! Item AV-29VX71/G AV-29VX71/S AV-2937V1/E

! MAIN PWB ASS’Y SCH-1170A-H2 SCH-1186A-H2 SCH-1187A-H2

QMPR340-165-K2 QMPR370-165-E2 QMPR340-165-K2

! POWER CORD

2.3 FUNCTIONS

REMOTE CONTROL UNIT

RM-C1302-1H

3 4 5

9 10 11 12

13 14 15

RM-C1302

25 26

MUTING key

COLOUR SYSTEM key

SOUND SYSTEM key

DISPLAY key

MENU (/, /) keys

TV/VIDEO key

OFF TIMER key

PICTURE MODE key

CHANNEL SCAN key

RETERN + key

CHANNEL (-/+) keys

FAVORITE CH keys

SUB-/REVEAL key

SUB+/HOLD key

C.SYS/SUB PAGE key

FREEZE/STORE key

POWER key

PIP key

CINEMA SURROUND key

ECO SENSOR key

TV/TEXT keys

Number keys

-/-- key

VOLUME (-/+) key

SWAP/INDEX key

INPUT/SIZE key

CANCEL key

POSITION/MODE Key

1-4 (No. 52192)

FRONT PANEL CONTROLS

REAR TERMINAL

HEADPHONE jack

IN (VIDEO-3) : VIDEO

IN (VIDEO-3) : AUDIO L/MONO

IN (VIDEO-3) : AUDIO R

MENU () button

CHANNEL (-/+) buttons

5 6 10 118

6 7

VOLUME (-/+) buttons

TV/VIDEO buttons

Remote control sensor

ECO sensor

POWER lamp

MAIN POWER button

11 12

VIDEO-1 INPUT TERMINAL

S-VIDEO

VIDEO

AUDIO L/MONO

AUDIO R

COMPONENT (VIDEO-2) INPUT TERMINAL

Y/VIDEO

AUDIO L/MONO

AUDIO R

OUTPUT TERMINAL

VIDEO

AUDIO L

AUDIO R

Aerial input terminal

(No. 52192) 1-5

SECTION 3

DISASSEMBLY

3.1 DISASSEMBLY PROCEDURE

3.1.1 REMOVING THE REAR COVER

• Unplug the power cord. (1) Remove the 16 screws [A] as shown in Fig.1.

(2) Withdraw the REAR COVER toward you.

CAUTION:

When reinstalling the rear cover, carefully push it inward after inserting the MAIN PWB into the REAR COVER groove.

3.1.2 REMOVING THE CHASSIS (CHASSIS BASE AND

CONTROL BASE)

• Remove the REAR COVER. (1) Slightly raise the both sides of the CHASSIS by hand

and remove the 2 claws [B] under the CHASSIS from the front cabinet as shown in Fig.1.

(2) Withdraw the CHASSIS backward.

(If necessary, take off the wire clamp, connector's etc.)

NOTE:

When conducting a check with power supplied, be sure to confirm that the CRT earth wire is connected to the CRT SOCKET PWB and the MAIN PWB.

3.1 .5 REMOVING THE SPEAKER

• Remove the REAR COVER. (1) Remove the 2 screws [G] as shown in Fig.1.

(2) Withdraw the SPEAKER backward. (3) Follow the same steps when removing the other hand

SPEAKER.

3.1.6 CHECKING THE MAIN PW BOARD

• To check the back side of the MAIN PWB. (1) Pull out the CHASSIS. (Refer to REMOVING THE

CHASSIS).

(2) Erect the CHASSIS vertically so that you can easily

check the back side of the MAIN PWB.

CAUTIONS:

• When erecting the chassis, be careful so that there will be no contacting with other PW Board.

• 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.

3.1.3 REMOVING THE AV TERMINAL BOARD

• Remove the REAR COVER. (1) Remove the 4 screws [C] as shown in Fig.1.

(2) When you pull out the AV TERMINAL BOARD in the

direction of arrow [D] as shown in Fig.1, it can be removed.

3.1.4 REMOVING THE CONTROL BASE

• Remove the REAR COVER.

• Remove the CHASSIS.

(1) While pushing down the 2 claws [E] as shown in Fig.

2 and pull out the CONTROL BASE in the direction of arrow [F] as shown in Fig. 2, the control base can be removed. (If necessary, take off the wire, connector's etc.)

3.1.7 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.

1-6 (No. 52192)

PICTURE TUBE

[FRONT SIDE]

CONTROL BASE

SPEAKER

FRONT CABINET

FRONT CONTROL PWB (1/2)

(X2)

CONTROL BASE

SPEAKER

CHASSIS BASE

CRT SOCKET PWB

Fig.2

CLAW B (under side)

(X2)

CHASSIS BASE

Fig.2

FRONT CONTROL PWB (2/2)

MAIN PWB

CLAW B (under side)

AV TERMINAL BOARD

(×4)

REAR COVER

Fig. 1

(×16)

(No. 52192) 1-7

3.4 REPLACEMENT OF MEMORY IC

3.4.1 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 PARTS LIST”. For its mounting location, refer to “ADJUSTMENT LOCATIONS”.

3.4.2 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 [ the MENU

!]/["] key, and set the correct value with

[#]/[$] 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).

6. User setting

Check the user setting values in Table 2 and Table 3. If setting value is different, set the correct value. For setting, refer to the

OPERATING INSTRUCTIONS

7. Setting of SERVICE MENU

Verify the setting for each setting item in the SERVICE MENU.(See Table 4.) If readjustment is necessary, perform adjustment referring to “ADJUSTMENTS PROCEDURE”.

SERVICE MENU

1. IF

3. DEF

5. PRESET

6. PIP

1-7 : SELECT DISPLAY : EXIT

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

2. VC

4. VSM PRESET

PLUG & PLAY (ON)

Fig. 1

SYSTEM CONSTANT-

SYSTEM CONSTANT SET 1

SYSTEM COMB TILT SUPER BASS TEXT LANGUAGE

: SEL -+ : OPE

MULTI YES YES NO ERAPU E/R/A/P

DISP : EXIT

SYSTEM CONSTANT-

SYSTEM CONSTANT SET 2

MSP BILINGUAL B / B SOUND TUNER COLOUR AUTO

: SEL -+ : OPE

NO NO NO MU NO

DISP : EXIT

SYSTEM CONSTANT-

SYSTEM CONSTANT SET 3

LOCK 1 MHz

500 KHz 250 KHz

156. 25 KHz

31.25 KHz

: 040 : 040 : 040 : 030 : 030

DISPLAY

PICTURE MODE

1-8 (No. 52192)

NAME OF REMOTE CONTROL KEYS

: SEL -+ : OPE

SYSTEM CONSTANT-

SYSTEM CONSTANT SET 4

3D SURROUND

: SEL -+ : OPE

Fig. 2

DISP : EXIT

YES

NOAMP TUNER YESCOMPONENT YESPIP YES16 : 9

ONM.L. delete

DISP : EXIT

3.4.3

FACTORY SETTING VALUE

SETTING OF SYSTEM CONSTANT SET

Setting item Setting content

Setting value

AV-29VX71/G AV-29VX71/S AV-2937V1/E

SYSTEM MULTI ←←

COMB YES ←←

TILT YES ←←

SUPER BASS NO ←←

TEXT ERAPU ←←

LANGUAGE E/R/A/P ← E/R/A/P/U

MSP NO ←←

BILINGUAL NO ←←

B/B SOUND NO YES NO

TUNER MU ←←

COLOUR AUTO NO YES NO

LOCK 1MHz 040 ←←

500KHz 040 ←←

250KHz 040 ←←

MULTI TRIPLE PAL SINGLE

YES NO

ERCMI ERAPU NO

E/R/A/P/U E/R/A/P E/R/U E

YES NO

MU MA

YES NO

000 240

VIET

156.25KHz 030 ←←

31.25KHz 030 ←←

3D SURROUND YES ←←

AMP TUNER NO ←←

COMPONENT YES ←←

PIP YES ←←

16 : 9 YES ←←

M.L. delete ON ←←

000 240

YES NO

ON OFF

Table 1

(No. 52192) 1-9

SETTING OF SWITCHES ON FRONT PANEL AND REMOTE CONTROL UNIT

Setting item Setting value

POWER Off

SUB POWER On

VOLUME 15

COLOR SYSTEM PAL

SOUND SYSTEM B/G

PICTURE MODE (VSM) BRIGHT

CINEMA SURROUND OFF

OFF TIMER 00

CHANNEL POSITION PRESET 1

Table 2

SETTING OF MENU SCREEN

Setting item Setting value

INPUT TV

VNR OFF

COMPRESS (16:9) OFF

AUTO SHUTOFF OFF

CHILD LOCK OFF

BLUE BACK ON

VIDEO-2 SET VIDEO

AUTO CH PRESET Refer to OPERATING INSTRUCTIONS

MANUAL CH PRESET Refer to OPERATING INSTRUCTIONS

LANGUAGE ENG

TEXT LANGUAGE GROUP-4 [AV-29VX71/G, AV-29VX71/S], GROUP-3 [AV-2937V1/E]

TINT Center

COLOUR Center

BRIGHT Center

CONT Maximum

SHARP Center

BASS Center

TREBLE Center

BALANCE Center

AI VOLUME ON

FAVORITE CH RED PR1

FAVORITE CH GREEN PR2

FAVORITE CH YELLOW PR3

FAVORITE CH BLUE PR4

AI ECO SENSOR OFF

AI ECO DISPLAY OFF

PIP INPUT MODE VIDEO-1

PIP POSITION Lower left

Table 3

1-10 (No. 52192)

+ 22 hidden pages

JVC AV-2937V1/E, AV-29VX71/G, AV-29VX71/S Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

TABLE OF CONTENTS

SPECIFICATION