JVC AV-14A14/A, AV-14A14/H, AV-14AG14/U, AV-14AMG4/G, AV-14AMG4/S Service Manual

YA150200411

SERVICE MANUAL

COLOUR TELEVISION

AV-14A14/A, AV-14A14/H,

AV-14AG14

AV-14AMG4

/U, AV-14AMG4/G,

BASIC CHASSIS

TABLE OF CONTENTS

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

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

3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

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

5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-28

No.YA150

2004/12

SPECIFICATION

Contents

Items

Dimensions (W × H × D) 36.4cm × 33.35cm × 37.4cm

Mass 9kg

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

Colour System TV Mode

Video Mode

Receiving Frequency VHF Low

VHF High

Intermediate Frequency

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

Aerial Input Terminal 75Ω unbalanced, coaxial

Power Input AC110V ~ AC240V, 50Hz / 60Hz

Power Consumption 65W (Max.) / 48W (Avg.) 50W, 0.4A 65W (Max.) / 48W (Avg.)

Picture Tube A34JXV70X

Screen Size Visible size : 34.0cm (Diagonal) / 28.7cm × 21.7cm (H × V)

High Voltage 22.5kV±1.5kV (at zero beam current)

Speaker 8cm, round type × 1

Audio Output 3W

Video / Audio Input [1/2]

Video / Audio Output Video

Headphone 3.5mm stereo mini jack × 1

Remote Control Unit RM-C1261-2H

Video [1/2] Audio [1/2]

PAL / SECAM

PAL / SECAM / NTSC3.58 / NTSC4.43

46.25MHz ~ 168.25MHz (AU0 ~ S10)

175.25MHz ~ 463.25MHz (E5 ~ S41)

UHF

471.25MHz ~ 863.25MHz (E21 ~ CHINA 57)

CATV

Mid : X ~ Z, S1 ~ S10 Super: S11 ~ S20 Hyper: S21 ~ S41

VIF 38.0MHz

SIF D/K: 31.5MHz (6.5MHz)

I: 32.0MHz (6.0MHz) B/G: 32.5MHz (5.5MHz)

14-inch, aspect ratio 4:3, conventional square face type, tinted

1V(p-p), negative sync, 75Ω, RCA pin jack × 2 500mV(rms) (-4dBs ), high impedance, RCA pin jack × 2

1V(p-p), 75Ω, RCA pin jack × 1

Audio

500mV(rms)(-4dBs), Low impedance (400Hz when modulated 100%), RCA pin jack × 1

(AA/R06/UM-3 battery × 2)

AV-14A14/A AV-14A14/H

AV-14AG14/U AV-14AMG4/G AV-14AMG4/S

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

D/K: 31.5MHz (6.5MHz) I: 32.0MHz (6.0MHz) B/G: 32.5MHz (5.5MHz) M: 33.5MHz (4.5MHz)

Design & specifications are subject to change without notice.

1-2 (No.YA150)

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 ( ) 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 (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 : ( ) 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 B1 POWER SUPPLY check).

(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 10kΩ

2W resistor to the anode button.

(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 sensitivity in the following manner. Connect a 1500

Ω per volt or more

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 1000 /V,

OR MORE SENSITIVITY)

0.15 F AC-TYPE

PLACE THIS PROBE

1500 10W

GOOD EARTH GROUND

ON EACH EXPOSED ME TAL PAR T

(No.YA150)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 input terminals.

C bus control utilizes single chip ICs.

•I

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

• Built-in OFF TIMER & RETURN +.

2.2 MAIN DIFFERENCE LIST

Items AV-14A14/A AV-14A14/H AV-14AG14/U

POWER CONSUMPTION 65W (Max.) / 48W (Avg.) 50W, 0.4A 65W (Max.) / 48W (Avg.)

PLUG TYPE

Items AV-14AMG4/G AV-14AMG4/S

POWER CONSUMPTION 65W (Max.) / 48W (Avg.) ←

PLUG TYPE

2.3 FUNCTIONS

 REMOTE CONTROL UNIT

RM-C1261-2H

7 8

SOUND SYSTEM key

COLOUR SYSTEM key

FAVORITE CHANNEL keys

TV / VIDEO key

PICTURE MODE key

Not used

OFF TIMER key

RETURN + key

DISPLAY / BACK key

CHANNEL (-/+) keys

POWER key

Number keys

-/-- key

MENU(OK) key

(/, /

MUTING key

VOLUME (-/+) keys

) keys

1-4 (No.YA150)

 FRONT PANEL CONTROLS

VIDEO AUDIO

IN (VIDEO-2)

CHANNEL

VOLUME

 REAR TERMINAL

HEADPHONE jack

IN (VIDEO-2) : VIDEO

IN (VIDEO-2) : AUDIO

MENU (OK) button

CHANNEL (-/+) buttons

VIDEO-1

INPUT

OUTPUT

VOLUME (-/+) buttons

Remote control sensor

POWER lamp

MAIN POWER button

VIDEO-1 INPUT TERMINAL

VIDEO

AUDIO

OUTPUT TERMINAL

1 2 4

VIDEO

AUDIO

VIDEO

AUDIO

Aerial input terminal

(No.YA150)1-5

2.4 MAIN CPU [MAIN PWB : IC701] PIN FUNCTION

Pin no.

1VssP2 -GND 2VssC4 -GND 3 V1.8C4 I 1.8V (Digital) 4 V3.3A3 I 3.3V 5 VrefP_Sdac I 3.3V (Positive) 6 VrefN_Sdac - GND 7 VrefP_Sdac I 3.3V (Negative) 8 VrefN_Sdac - GND

9 VrefP_Sdac I 3.3V (Positive) 10 XtalIn I 24.576MHz for system clock 11 XtalOut O 24.576MHz for system clock 12 VssA1 - GND 13 NECK I V-guard input/ I/O switch 14 CONT I 1.8V regulator control 15 V5P1 I +5V 16 Ph2 - Phase-2 filter 17 Ph1 - Phase-1 filter 18 Gnd1 - GND 19 SecPll - SECAM PLL decoupling 20 Dec8G - Bandgap decoupling 21 EW O East-West drive output 22 VDRB- O Vertical drive B output 23 VDRA+ O Vertical drive A output 24 Vif1 I Video IF input 1 25 Vif2 I Video IF input 2 26 Vsc - Vertical sawtooth capacitor 27 Iref I Reference current input 28 GndIF - GND 29 Sif1 I Sound IF input 1 30 Sif2 I Sound IF input 2 31 AGC O Tuner AGC output 32 EHT I EHT/overvoltage protection input 33

34 L3 I Audio-L3 input (left signal) 35 R3 I Audio-R3 input (right signal) 36 L-OUT O Audio L output 37 R-OUT O Audio R output 38 DecsDem - Decoupling sound demodulator 39

40 Gnd2 - GND 41 PllIf - IF-PLL loop filter 42 SifAgc - AGC sound IF 43 IfVo/FmRo/DvbO O Not used 44 NC O Not used 45 V8AudioSwitches I 8V 46 AgcSsif - AGC capacitor second sound IF 47 V5P2 I 5V 48 V-OUT O Video output 49 L1 I Audio-L1 input 50 R1 I Audio-R1 input 51 V3 I Video V3 input 52 C4 I Not used 53 Audio2InL I Not used 54 Audio2InR I Not used 55 V2/Y I Video V2 input 56 L2 I Audio L2 input (Left signal) 57 R2 I Audio R2 input (right signal) 58 Y3/Cvbs I S-Video Y1 input 59 C1 I S-Video C1 input 60 AudioLsL O 61 AudioLsR O 62 HP-L O Headphone L 63 HP-R O Headphone R

Pin name I/O Function

Ssif/RefIn/Avl/RefOut

QssO/AmO/AudeEm

Automatic Volume Levelling/ sound IF input / subcarrier reference output / external reference signal input for I signal mixer for DVB operation

O QSS intercarrier output / AM output /

deemphasis / (front-end audio out)

Audio L output for audio power amplifier Audio R output for audio power amplifier

1-6 (No.YA150)

no.

64 CVBSO/PIP O CVBS / PIP output 65 SVM O Scan velocity modulation output 66 FbiSo I Flyback input/sandcastle output 67 Hout O Horizontal output 68 VssComb - GND 69 V5Comb I 5V 70 Vin/R2/Pr I PIP R input 71 Uin/B2/Pb I PIP B input 72 Yin/G2/Y I PIP G input 73 Ysync I Not used 74 Yout O Not used 75 Uout/INSSW2 I YUV insertion input 76 NC O Not used 77 INSSW3 I YUV insertion input 78 R3/Pr I Component PR input (Video-2) 79 G3/Y I Component Y input (Video-2) 80 B3/Pb I Component PB input (Video-2) 81 Gnd3 - GND 82 V5P3 I 5V 83 BCL I Beam current limiter input 84 BLKIN I Black current input 85 Rout O R output 86 Gout O G output 87 Bout O B output 88 V3.3A1 I 3.3V 89 RefAdN - GND 90 V3.3RefAdP I 3.3V (Positive) 91 RefAd I 3.3/2V 92 GndA - GND 93 V1.8A I 1.8V 94 V3.3A2 I 3.3V 95 VssADC - GND 96 V1.8ADC I 1.8V 97 REMOTE I Remote control 98 PW_LED I POWER LED control

99 P11/TO I POWER LED control 100 V1.8C2 I 1.8V 101 VssC2 - GND 102 103 104 VER_PROTECT O X-ray protect 105 S_REDUCE O Sound control 106 P00/I2SDI1 O Not used 107 POWER O SUB POWER control 108 SCL1 I I2C bus clock 109 SDA1 I/O I2C bus data 110 V3.3P I 3.3V 111 ROTATION O ROTATION 112 3.58/OTHER O NTSC 3.58 detection 113 A_MUTE O Audio muting 114 4.5/OTHER O NTSC 4.43 detection 115 PROT I Protect 116 ECO_IN I ECO sensor level detection 117 V1.8C1 I 1.8V (Digital) 118 DecV1V8 I 1.8V 119 KEY_IN I Key scan data 120 VDO-DET I Video DET input 121 VSSC1+P1 - Digital GND 122 P24/PWM3 I S-Video DET input 123 P25/PWM4 O GTVA_reset 124 V1.8C3 I 1.8V (Digital) 125 VssC3 - GND 126 P12/Int2 I External interrupt 127 SDA0 I/O I2C bus data (for memory) 128 SCL0 I I2C bus clock (for memory)

Pin name I/O Function

COMPONENT-PIP COMB_SW_NT3.5/OTHER

- Not used

SECTION 3

DISASSEMBLY

3.1 DISASSEMBLY PROCEDURE

3.1.1 REMOVING THE REAR COVER

• Unplug the power cord. (1) Remove the 4 screws [A], 2 screws [B] and 1 screw [C] 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 MAIN PW BOARD

• Remove the REAR COVER. (1) Slightly raise the both sides of the MAIN PWB by hand. (2) Withdraw the MAIN PWB backward.

(If necessary, take off the wire clamp and connectors, etc.)

3.1.3 REMOVING THE SPEAKER

• Remove the REAR COVER.

• Remove the MAIN PW BOARD. (1) Raise the SPEAKER HOLDER claw [D] slightly, and

remove the SPEAKER HOLDER.

(2) Remove the SPEAKER.

3.1.4 CHECKING THE MAIN PW BOARD

• 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.

CAUTIONS:

• 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.

• When repairing, connect the DEG. COIL to the DEG.

connector on the MAIN PWB.

3.1.5 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.

(No.YA150)1-7

PICTURE TUBE

FRONT CABINET

MAIN PWB (CRT SOCKET PWB)

SPEAKER

SPEAKER HOLDER

FBT

MAIN PWB

1-8 (No.YA150)

REAR COVER

Fig.1

(x2)

(x4)

3.2 REPLACEMENT OF MEMORY IC

3.2.1 MEMORY IC

This TV uses the following memory IC.

Memory IC: IC702 on MAIN PWB

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".

3.2.2 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 Table 1. If the value is different, select the setting item with the MENU [] / [] key, and set the correct value with the MENU [] / [] 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. AUDIO

5. VSM W/B

7. PLUG & PLAY (ON)

1-7 : SELECT DISPLAY : EXIT

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

2. V/C

4. DEF

6. S TATUS

Fig.1

SYSTEM CONSTANT-1

SYSTEM CONSTANT SET 1

SYSTEM COMB TILT SUPER BASS TEXT LANGUAGE



: SEL  : OPE

SYSTEM CONSTANT-2

SYSTEM CONSTANT SET 2

SOUND BILINGUAL BLUE BACK MUTE COLOUR AUTO ECO SENSOR

: SEL  : OPE



SYSTEM CONSTANT-3

SYSTEM CONSTANT SET 3

SURROUND

: SEL  : OPE



TRIPLE NO NO NO NO ERCMI

DISP : EXIT

MONO NO NO NO NO

DISP : EXIT

NO NOPICTURE BOOSTER NOCOMPONENT NOPIP NOS INPUT

DISP : EXIT

NAME OF REMOTE CONTROL KEYS

PICTURE MODE

DISPLAY / BACK

MENU OK MENU

MENU MENU

Fig.2

(No.YA150)1-9

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