JVC AV-21MS25, AV-21MX75 Schematic

SERVICE MANUAL

FLAT COLOUR TELEVISION

YA26720055

AV-21MS25, AV-21MX75/G

BASIC CHASSIS

CW2

EXIT

RM-C1286

[AV-21MS25]

[AV-21MX75/G]

EXIT

TABLE OF CONTENTS

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

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

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

4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12

5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29

No.YA267

2005/5

SPECIFICATION

Items

Dimensions (W × H × D) 64.9cm × 46.53cm × 46.92cm

Mass 23.5kg

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

Colour System TV Mode

Video Mode

Stereo System A2 (B/G) / NICAM (B/G, I, D/K) Playback

Teletext system FLOF (Fastext)

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 112W (Max.) / 80W (Avg.)

Picture Tube 21-inch, aspect ratio 4:3, flat square face type, tinted

Screen Size Visible size : 51.0cm (Diagonal) / 41.6cm × 31.5cm (H × V)

High Voltage 29kV±1.5kV (at zero beam current)

Speaker 6.5cm × 13cm, Oval type × 2

Audio Output 7W + 7W

Video / Audio Input (1/2/3)

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

Headphone 3.5mm stereo mini jack × 1

Remote Control Unit RM-C1286-1H

S-Video [1] Mini-DIN 4 pin × 1

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

Video [2]

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

WST (World Standard Text)

46.25MHz ~ 140.25MHz (AS0 ~ S6)

147.25MHz ~ 423.25MHz (S7 ~ S36)

UHF

431.25MHz ~ 863.25MHz (S37 ~ C57)

CATV

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

VIF 38.0MHz

SIF D/K: 31.5MHz (6.5MHz)

[NICAM: 32.15MHz (5.85MHz)] I: 32.0MHz (6.0MHz) [NICAM: 31.45MHz (6.55MHz)] B/G: 32.5MHz (5.5MHz) [A2: 32.26MHz (5.74MHz)] [NICAM: 32.15MHz (5.85MHz)] M: 33.5MHz (4.5MHz)

Y: 1V(p-p), positive (negative sync provided), 75Ω C: 0.286V(p-p) (Burst signal), 75Ω

RCA pin jack × 3 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)

AV-21MS25 AV-21MX75/G

Contents

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

RM-C1285-1H

(AA/R06/UM-3 battery × 2)

Design & specifications are subject to change without notice.

1-2 (No.YA267)

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 1000Ω per volt or more sensitivity in the following manner. Connect a 1500Ω 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.YA267)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.

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 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

Items AV-21MS25 AV-21MX75/G

STEREO SYSTEM A2 / NICAM Playback

PIP --- YES

1-4 (No.YA267)

2.3 MAIN CPU [MAIN PWB : IC701] PIN FUNCTION

Pin No.

1VssP2 -GND 2 VssC4 - 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 Ssif/RefIn/Avl/RefOut O

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 Audio L output for audio power amplifier 61 AudioLsR O Audio R output for audio power amplifier 62 HP-L O Not used

Pin name I/O Function

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

QssO/AmO/AudeEm

O QSS intercarrier output / AM output /

deemphasis / (front-end audio out)

Pin No.

63 HP-R O Not used 64 CVBSO/PIP O CVBS / PIP output 65 SVM O Not used 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 PW_LED I POWER LED control 100 V1.8C2 I 1.8V 101 VssC2 - GND 102 TIMER - Not used 103 TIMER - Not used 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 S_V_DET 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

(No.YA267)1-5

SECTION 3

DISASSEMBLY

3.1 DISASSEMBLY PROCEDURE

3.1.1 REMOVING THE REAR COVER

• Unplug the power cord. (1) Remove the 9 screws [A] and 4 screws [B] 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. (1) Remove the 2 screws [C] as shown in Fig.1. (2) Follow the same steps when removing the other hand

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.

1-6 (No.YA267)

PICTURE TUBE

FRONT CABINET

(x2)

SPEAKER

MAIN PWB (CRT SOCKET PWB)

SPEAKER

(x2)

MAIN PWB

FBT

(FRONT LED PWB)

MAIN PWB

(x9)

REAR COVER

Fig.1

(x4)

(No.YA267)1-7

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".

NAME OF REMOTE CONTROL KEYS

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

Fig.2

: MULTI

NO NO NO PAT ERCMI

DISP : EXIT

STEREO NO NO NO YES

DISP : EXIT

YES NOPICTURE BOOSTER YESCOMPONENT NOPIP YESS INPUT

DISP : EXIT

DISPLAY / BACK

1-8 (No.YA267)

PICTURE MODE

3.2.3 FACTORY SETTING VALUE

 SETTING OF SYSTEM CONSTANT SET

Setting item Setting content

SYSTEM

MULTI TRIPLE PAL THAI

COMB

TILT

SUPER BASS

TEXT

SINGLE NO PAT

LANGUAGE

SOUND

STEREO PB MONO

BILINGUAL

BLUE BACK MUTE

COLOUR AUTO

ECO SENSOR

SURROUND

PICTURE BOOSTER

COMPONENT

PIP

S INPUT

YES NO

E/R/C/M/I E/C

E/R/A/P/F

YES NO

Table 1

AV-21MS25

MULTI

PAT

E/R/C/M/I

---

STEREO

YES

Setting value

AV-21MX75/G

---

E/R/A/P/F

YES

(No.YA267)1-9

 SETTING OF BASIC FUNCTIONS

Setting item Setting value

POWER Off

SUB POWER On

VOLUME 15

INPUT TV

COLOR SYSTEM PAL

SOUND SYSTEM B/G

PICTURE MODE (VSM) BRIGHT

CINEMA SURROUND (RF)

OFF TIMER OFF

CHANNEL POSITION PR1

 SETTING OF MENU SCREEN

Setting item Setting value

VNR AUTO

COMPRESS (16:9) OFF

CHILD LOCK OFF

BLUE BACK ON

VIDEO-2 SET COMPONENT

AUTO PROGRAM

EDIT / MANUAL

LANGUAGE ENG

TEXT LANGUAGE GROUP-1 [AV-21MS25]

WHITE BALANCE (RF) COOL

BALANCE Centre

SOUND MODE (RF) MUSIC

AI VOLUME OFF

FAVORITE CH RED PR01

FAVORITE CH GREEN PR02

FAVORITE CH YELLOW PR03

FAVORITE CH BLUE PR04

AI ECO SENSOR OFF

AUTO SIGNAL DETECT ON

DVD PICTURE MODE OFF

TINT COLOR Centre

WHITE BALANCE (DVD) COOL

SOUND MODE (DVD) MUSIC

CINEMA SURROUND (DVD)

PIP OFF [AV-21MX75/G]

PIP SUB INPUT MODE VIDEO-1 [AV-21MX75/G]

PIP POSITION Lower Left [AV-21MX75/G]

OFF

Table 2

Refer to OPERATING INSTRUCTIONS

GROUP-4 [AV-21MX75/G]

OFF

Table 3

 SERVICE MENU SETTING ITEMS

Setting item Setting value

1. IF 1. VCO

2. DELAY POINT

2. V/C 1. SCREEN

2. CUTOFF(B/G)

3. WDR(R/G/B)

4. BRIGHT(TV/VDO 1/2/3)

5. CONT(TV/VDO 1/2/3/TV 16:9/VDO 16:9)

6. COLOUR(TV/VDO1/2/3/DVD)

7. TINT(TV/VDO 1/2/3)

8. SHARP [Do not adjust]

9. Y DELAY [Do not adjust]

10. TINT DVD [Do not adjust]

11. AMP T. SHARP

12. TWIN CONT.

3. AUDIO [Do not adjust]

4. DEF 1. V-SHIFT

5. VSM W/B (BRIGHT/STANDARD/SOFT)

(COOL/WARM/NORMAL)

6. STATUS [Display only]

7. PLUG & PLAY(ON) [Display only]

1. DCXO ADJ

2. NICAM lower ERRLIM

3. NICAM upper ERRLIM

4. A2 ID THR

5. MENU EQUALIZER

2. V-SLOPE

3. V-SIZE

4. H-CENT

5. H-SIZE

6. TRAPEZ

7. EW-PIN

8. COR-UP

9. COR-LO

10. ANGLE

11. BOW

12. V-S.CR

13. V-LIN

14. V-ZOOM

15. V-SCROLL

1. BRIGHT

2. CONT

3. COLOUR

4. SHARP

5. HUE

1. R DRIVE

2. G DRIVE

3. B DRIVE

Table 4

1-10 (No.YA267)

3.3 REPLACEMENT OF CHIP COMPONENT

3.3.1 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.

3.3.2 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.

3.3.3 REPLACEMENT STEPS

1. How to remove Chip parts

2. How to install Chip parts

[Resistors, capacitors, etc.]

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

alternately melt the solder at each end.

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

[Transistors, diodes, variable resistors, etc.]

(1) Apply extra solder to each lead.

SOLDER

[Resistors, capacitors, 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. 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.

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

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

NOTE :

After removing the part, remove remaining solder from the pattern.

(4) Then solder leads B and C.

(No.YA267)1-11

SECTION 4

ADJUSTMENT

4.1 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 used for setting 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 variable resistors, transformers, trimmer capacitors,

etc.

4.2 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

AI ECO SENSOR OFF

BALANCE Centre

CINEMA SURROUND OFF

COMPRESS (16:9) OFF

4.3 MEASURING INSTRUMENT AND FIXTURES

(1) DC voltmeter (or Digital voltmeter) (2) Oscilloscope (3) Signal generator (Pattern generator) [PAL/SECAM/NTSC] (4) Remote control unit

4.4 ADJUSTMENT ITEMS

 B1 VOLTAGE  FOCUS ADJUSTMENT  IF CIRCUIT ADJUSTMENTS

• IF VCO adjustment

• DELAY POINT (AGC TAKE-OVER) adjustment  VIDEO CIRCUIT ADJUSTMENTS

• WHITE BALANCE (Low light) adjustment

• WHITE BALANCE (High light) adjustment

• SUB BRIGHT adjustment

• SUB CONTRAST adjustment

• SUB COLOUR 1 adjustment

• SUB COLOUR 2 adjustment

• SUB TINT 1 adjustment

• SUB TINT 2 adjustment

 AUDIO SETTING

 DEFLECTION CIRCUIT ADJUSTMENTS

• V.SLOPE adjustment

• V.POSITION adjustment

• V.HEIGHT adjustment

• H.POSITION adjustment

• V. LINEARITY adjustment

• H. PARALLEL adjustment

• H.BOW adjustment

 VSM PRESET SETTING  PURITY AND CONVERGENCE ADJUSTMENTS

• PURITY adjustment

• STATIC CONVERGENCE adjustment

• DYNAMIC CONVERGENCE adjustment

1-12 (No.YA267)

4.5 ADJUSTMENT LOCATIONS

POWER CORD

DEG COIL

MAIN PWB ASS'Y

POWER SW

S901

DEG

MAIN PWB ASS'Y (FRONT LED)

CN10A

S805

CN00A

S804 S802

S803 S801

IC701

TOP

J808

J807

IC702

J806

J809

CN00S

FRONT

DEF YOKE

GND

J804J801 J802 J803

TU001

1. 5V

I2C

2. SCL0

3. SDA0

4. SCL1

5. SDA1

6. GND

CN00C

CN00X

1. B1

2. NC

3. X-RAY2

4. X-RAY1

5. GND

MAIN PWB ASS'Y (CRT SOCKET)

(SOLDER SIDE)

TP-47G/R

TP-47B

HVT

UPPER : FOCUS

LOWER : SCREEN

TOP

TP-47R/G

TP-E

CRT EARTH

(BRAIDED ASS'Y)

(No.YA267)1-13

4.6 BASIC OPERATION IN SERVICE MENU

Operate the SERVICE MENU with the remote control unit.

4.6.1 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. V/C For entering/adjusting the setting values (adjustment values) of the VIDEO circuit.

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

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

5. VSM W/B For setting the values of STANDARD, SOFT, BRIGHT and COOL, NORMAL, WARM.

6. STATUS This is not used for service.

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

4.6.2 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.)

SERVICE MENU → SUB MENU

1. IF 5. VSM W/B

2. V/C 6. STATUS

3. AUDIO 7. PLUG & PLAY (ON)

4. DEF

3. METHOD OF SETTING

NOTES:

• Once the setting values are set, they are memorized automatically.

• It must not be adjusted without inputting a signal.

(1) 1. IF

[1.VCO ] : Under normal conditions, no adjustment is required.

(a) [1] key Select 1. IF. (b) [1] key Select 1. VCO. (c) [DISPLAY] key When this is pressed twice, you will return to the SERVICE MENU.

[2.DELAY POINT ]

(a) [1] key Select 1. IF. (b) [2] key Select 2. DELAY POINT. (c) MENU [] / [] key Adjust the setting value. (d) [DISPLAY] key When this is pressed twice, you will return to the SERVICE MENU.

(2) 2. V/C, 3. AUDIO and 4. DEF

(a) [2] ~[4] keys Select one from 2. V/C, 3. AUDIO and 4. DEF (b) MENU [] / [] key Select setting items. (c) MENU [] / [] key Adjust the setting values of the setting items.

Use the number keys on the remote control unit for setting the WHITE BALANCE. For the setting, refer to each item concerned.

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

(3) 5. VSM W/B

(a) [5] keys Select 5. VSM W/B. (b) MENU [OK] key Select preset items. (c) MENU [] / [] key Adjust setting items. (d) MENU [] / [] key Adjust the setting values of the setting items. (e) [DISPLAY] key When this is pressed, you will return to the SERVICE MENU.

(4) 6. STATUS

This is for display only.

(5) 7. 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.

1-14 (No.YA267)

4.6.3 SERVICE MENU FLOW CHART

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. STATUS

IF SERVICE MENU

1. VCO

2. DELAY POINT

V/C

1. SCREEN

1. IF

2. V/C

PAL

HBC

WBC

BRI

VCO (CW)

TOO HIGH ABOVE REFERENCE JUST REFERENCE BELOW REFERENCE TOO LOW

DELAY POINT

AGC TAKEOVER

Setting item

1. SCREEN

2. CUTOFF (B/G)

** ** **

3. WDR (R/G/B)

4. BRIGHT (TV/VDO1/2/3)

5. CONT (TV/VDO1/2/3/TV 16:9/VDO16:9)

6. COLOUR (TV/VDO1/2/3/ DVD)

7. TINT (TV/VDO1/2/3)

8. SHARP (TV/VDO1/2/3) Y DELAY (TV/VDO1/2/3

/S-VDO)

10. TINT DVD

11. AMP T.SHARP

12. TWIN CONT.

*****

MHz

6. STATUS

STATUS

V/C STATUS

ECO EOF NOL VNR

****

ADC ECO =

COSMIC STATUS

*******

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

5. VSM W/B

VSM PRESET BRIGHT

1. BRIGHT

***

1. BRIGHT

2. CONT

3. COLOUR

4. SHARP

5.HUE

Setting item

1. R-DRIVE

2. G-DRIVE

3. B-DRIVE

3. AUDIO

AUDIO

1. DCXO ADJ. = NOT NICAM

0002

0009

000A

***

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

*******

4. DEF

DEF FULL 50Hz

1. V-SHIFT

***

(**)

Setting item

1. DCXO ADJ

2. NICAM lower ERRLIM

3. NICAM upper ERRLIM

4. A2 ID THR

MENU EQUALIZER

EQUALIZER RF

USER SOUND TURBO THEATER MUSIC NEWS

1. V-SHIFT

2. V-SLOPE

3. V-SIZE

4. H-CENT

5. H-SIZE

6. TRAPEZ

7. EW-PIN

8. COR-UP

EQUALIZER VIDEO EQUALIZER DVD

USER SOUND TURBO THEATER MUSIC NEWS

4 : 3 / 16 : 9

Setting item

Setting value (Hexadecimal)

Setting value

Sereen size

FULL COMPRESS

USER SOUND TURBO THEATER MUSIC NEWS

9. COR-LO

10. ANGLE

11. BOW

12. V-S. CR

13. V-LIN

14. V-ZOOM

15. V-SCROLL

Fig.1

(No.YA267)1-15

4.7 ADJUSTMENT PROCEDURE

4.7.1 B1 VOLTAGE

Item

B1 VOLTAGE check

Measuring

instrument

Signal generator

B1 (pin 1) GND (pin 5) [CN00X

DC voltmeter

connector in MAIN PWB]

4.7.2 FOCUS ADJUSTMENT

Item

FOCUS adjustment

Measuring

instrument

Signal generator

Test point Adjustment part Description

(1) Receive a PAL black and white signal. (2) Connect a DC voltmeter between B1 and GND

(between pins 1 and 5 of the connector CN00X).

(3) Make sure that the voltage is DC134.5V ± 2V.

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 affected by the FOCUS adjustment.) If any aeviation in CONVERGENCE is found, PURITY must be adjusted to restore the convergence.

(1) Receive a PAL crosshatch signal. (2) Adjust the FOCUS VR so that the vertical and

horizontal lines will be clear and in fine detail on the screen.

(3) Make sure that the picture is in focus even when the

screen gets darkened.

4.7.3 IF CIRCUIT ADJUSTMENTS

Item

IF VCO check

DELAY POINT (AGC

Measuring

instrument

Remote control unit

VCO (CW)

TOO HIGH ABOVE REFERENCE JUST REFERENCE BELOW REFERENCE TOO LOW

DISPLAY : EXIT

Remote control unit

. MHz

TAKE-OVER) adjustment

Adjustment item

2. DELAY POINT

(AGC TAKE-OVER)

Test point Adjustment part Description

[1. IF]

1. VCO (CW)

Note:

• Under normal conditions, no adjustment is required.

(1) Receive a PAL broadcast signal.

Receiving frequency

YELLOW

(2) Select 1. IF from the SERVICE MENU. (3) Select 1. VCO.

Check the characters colour of the

(4)

displayed to

yellow

(5) Press the [DISPLAY] key three times to return to

normal screen.

[1. IF]

2. DELAY POINT

(1)

Receive a PAL black and white broadcast signal (colour off). (2) Select 1. IF from the SERVICE MENU. (3) Select 2. DELAY POINT. (4) Adjust in order to eliminate any noise or beat from

the image. Any increase above the initial value

Initial setting value

NTSC 3.58

OTHERS

VHF UHF VHF UHF

produces the noise and any decrease below it

produces the beat. (5) Press the [DISPLAY] key three times to return to the

normal screen.

28*

(6) Turn to other channels and make sure that there are

no irregularities.

JUST REFERENCE

1-16 (No.YA267)

4.7.4 VIDEO 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 PROCEDURE".

• The initial setting values in parenthesis ( ) are fixed offset values, needing no further adjustment.

[AV-21MS25]

Initial setting value

Adjustment item Variable range

1. SCREEN BRI 0 ~ 63 31 31 31 31 31 31

2. CUTOFF B 0 ~ 63(-32 ~ +31) 43 43 43 43 (+0) (+0) G 0 ~ 63(-32 ~ +31) 28 28 28 28 (-3) (-3)

3. WDR R 0 ~ 63(-32 ~ +31) 35 35 35 35 (0) (0) G 0 ~ 63(-32 ~ +31) 32 32 32 32 (0) (0) B 0 ~ 63(-32 ~ +31) 40 40 40 40 (0) (0)

4. BRIGHT RF 0 ~ 63 34 34 34 34 --- --VIDEO 1(COMPOSITE/S) (-32 ~ +31) (+2) (+2) (+2) (+2) --- --VIDEO 2(COMPONENT) (-32 ~ +31) (+2) (+2) (+2) (+2) (+1) (+1) VIDEO 3(COMPOSITE) (-32 ~ +31) (+2) (+2) (+2) (+2) --- ---

5. CONT. RF 0 ~ 63 18 18 18 18 --- --VIDEO (-32 ~ +31) (-1) (-1) (-1) (-1) (-2) (-2)

6. COLOUR RF 0 ~ 63(-32 ~ +31) 42 29 31 (-2) --- --VIDEO (-32 ~ +31) (+2) (-1) (+1) (0) (+4) (+2)

7. TINT RF 0 ~ 63(-32 ~ +31) --- --- 32 (+3) --- --VIDEO (-32 ~ +31) --- --- (+2) (+3) --- ---

8. SHARP RF 0 ~ 63 48 48 48 48 --- --VIDEO 0 ~ 63 48 48 48 48 40 40

9. Y DELAY RF 0 ~ 15 5 7 5 4 --- --VIDEO 0 ~ 15 6977-----S-VIDEO 0 ~ 15 7 9 9 9 --- ---

10. TINT DVD RF 0 ~ 63(-32 ~ +31) 37 (0) (0) (0) --- --VIDEO (-32 ~ +31) (+1) (0) (0) (0) (+1) (-4)

11. AMP T.SHARP RF, VIDEO 0 ~ 63 0 0 0 0 0 0

12. TWIN CONT. TWIN (RF) -15 -15 -15 -15 --- --TWIN (VIDEO) --- --- --- --- --- ---

PAL SECAM

NTSC3.58 NTSC4.43

COMPONENT (V-2)

525i 625i

[AV-21MX75/G]

Initial setting value

Adjustment item Variable range

1. SCREEN BRI 0 ~ 63 31 31 31 31 31 31

2. CUTOFF B 0 ~ 63(-32 ~ +31) 43 43 43 43 (+0) (+0) G 0 ~ 63(-32 ~ +31) 28 28 28 28 (-3) (-3)

3. WDR R 0 ~ 63(-32 ~ +31) 35 35 35 35 (0) (0) G 0 ~ 63(-32 ~ +31) 32 32 32 32 (0) (0) B 0 ~ 63(-32 ~ +31) 40 40 40 40 (0) (0)

5. CONT. RF 0 ~ 63 18 18 18 18 --- --VIDEO (-32 ~ +31) (-1) (-1) (-1) (-1) (-2) (-2)

6. COLOUR RF 0 ~ 63(-32 ~ +31) 42 29 31 (-2) --- --VIDEO (-32 ~ +31) (+2) (-1) (+1) (0) (+4) (+2)

7. TINT RF 0 ~ 63(-32 ~ +31) --- --- 32 (+2) --- --VIDEO (-32 ~ +31) --- --- (+2) (+2) --- ---

8. SHARP RF 0 ~ 63 48 48 48 48 --- --VIDEO 0 ~ 63 48 48 48 48 40 40

9. Y DELAY RF 0 ~ 15 5 7 5 4 --- --VIDEO 0 ~ 15 6977-----S-VIDEO 0 ~ 15 7 9 9 9 --- ---

10. TINT DVD RF 0 ~ 63(-32 ~ +31) 37 (-8) (0) (0) --- --VIDEO (-32 ~ +31) (+1) (-8) (0) (0) (+1) (-4)

11. AMP T.SHARP RF, VIDEO 0 ~ 63 0 0 0 0 0 0

12. TWIN CONT. TWIN (RF) -15 -15 -15 -15 --- --TWIN (VIDEO) --- --- --- --- --- ---

PAL SECAM

NTSC3.58 NTSC4.43

COMPONENT (V-2)

525i 625i

(No.YA267)1-17

Item

WHITE BALANCE (Low light) adjustment

Measuring

instrument

Signal generator

Remote control unit

B CUTOFF (

Test point Adjustment part Description

V/C

2. CUTOFF

REMOTE CONTROL UNIT

12 3

)



789



)

PAL

(B)

(G)

[2. V/C]

2. CUTOFF (B)

2. CUTOFF (G)

SCREEN VR [In HVT]

(**)

)

(

G CUTOFF ( )



G CUTOFF (

)

Note:

• Set PICTURE MODE (VSM) to "BRIGHT".

- COMPOSITE WHITE BALANCE -

(1) Receive a PAL black and white signal (colour off). (2) Select 2. V/C from the SERVICE MENU. (3) Select 2. CUTOFF (B) and (G). (4) Set each value to initial setting value with the [4] / [7]

keys and [5] / [8] keys.

(5) Turn the SCREEN VR fully counterclockwise, then

slowly turn it clockwise to where a red, blue or green colour is faintly visible.

(6) Use the [4] / [7] and [5] / [8] keys to adjust so that

the other 2 colours appear white.

(7) Turn the SCREEN VR to where the single horizontal

line glows faintly.

(8) Press the [DISPLAY] key twice to return to the normal

screen.

- COMPONENT WHITE BALANCE -

(1) Receive a PAL component black and white signal

(colour off).

(2) Select VIDEO-2 SET from the MENU and set

VIDEO-2 SET to COMPONENT.

(3) Adjust COMPONENT WHITE BALANCE in the

same way as "COMPOSITE WHITE BALANCE".

Adjustment

Item

2. CUT OFF

range

B 0 ~ 63 (-32~+31)

0 ~ 63 (-32~+31)

G28

Initial setting valueVariable

COMPOSITE COMPONENT

(+0)

(-3)

WHITE BALANCE (High light) adjustment

Signal generator

Remote control unit

V/C

3. WDR

REMOTE CONTROL UNIT

12 3

R DRIVE (

) B DRIVE ()





R DRIVE (

)

789

PAL

[2. V/C]

3. WDR (R)

3. WDR (G)

3. WDR (B)

(R)

(G)

(B)

**(**

G DRIVE ()

B DRIVE (

G DRIVE (

(**)

(

Notes:

• Proceed to the following adjustment after having completed the WHITE BALANCE (Low light) adjustment.

• Set PICTURE MODE (VSM) to "BRIGHT".

(1) Receive a PAL black and white signal (colour off). (2) Select 2. V/C from the SERVICE MENU. (3) Select 3. WDR (R), (G) and (B). (4) Set each value to initial setting value with the [4] to

[9] keys.

) )

(5) Use the [4] to [9] keys to produce a white screen. (6) Press the [DISPLAY] key twice to return to the normal

screen.

Adjustment Item

3. WDR G



)



)

Variable Initial setting

range value

0 ~ 63

35*

40*

1-18 (No.YA267)

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