JVC AVN38A54/AYA - Service Manual Immediate Download

SERVICE MANUAL

No.52154

2003/7

COLOR TELEVISION

52154

2003

AV-N38A54/AYA

TABLE OF CONTENTS

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

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

DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14

TROUBLE SHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-35

ASPECT

LIGHT

SOURCE

INPUT

FREEZE SWAP

EZ SURF

CHANNEL

ON/MOVE

PIP

SOUND

C.C.

RM-C1250G

BASIC CHASSIS

GJ2

1-2 (No.52154)

SPECIFICATION

Design & specifications are subject to change without notice.

Items

Contents

Dimensions (W

× H × D)

102.3 cm

× 75.6 cm × 61.3cm (40-3/8" × 29-7/8" × 24-1/4")

Mass

85.0kg (187.0Ibs)

TV RF System

CCIR(M)

Color System

NTSC

Sound System

BTSC (Multi Channel Sound)

TV Receiving Channels

and Frequency

VHF LOW 02ch~06ch : 54MHz~88MHz

VHF HIGH 07ch~13ch : 174MHz~216MHz

UHF 14ch~69ch : 470MHz~806MHz

CATV 54MHz~804MHz

Low Band : 02~06, A-8 by 02~06&01

High Band : 07~13 by 07~13

Mid Band : A~I by 14~22

Super Band : J~W by 23~36

Hyper Band : W+1~W+28 by 37~64

Ultra Band : W+29~W+84 by 65~125

Sub Mid Band : A8, A4~A1 by 01, 96~99

TV / CATV Total Channel

180 Channels

Intermediate Frequency

Video IF Carrier 45.75 MHz

Sound IF Carrier 41.25 MHz (4.5MHz)

Color Sub Carrier

3.58 MHz

Power Input

AC120V , 60Hz

Power Consumption

160W

Picture Tube (Visible size)

90cm (36") Measured diagonally (H : 74.0cm

× W : 55.9cm)

High Voltage

31.4kV ±1.3kV

Speaker

6.5cm

× 13cm (2-1/2" × 5"), Oval type × 2

Audio Power Output

10W + 10W

Antenna Terminal (VHF / UHF)

F-type connector, 75

unbalanced

Input1 (Rear)

Video 1V(p-p), negative sync, 75

, RCA pin jack × 1

S-video Mini DIN 4-pin

× 1

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

C : 0.286V(p-p)(burst signal), 75

Audio 500mV(rms)(-4dBs), high impedance, RCA pin jack

× 2

Input2 (Rear)

Video 1V(p-p), negative sync, 75

, RCA pin jack × 1

Component Video Y : 1V(p-p), negative sync, 75

, RCA pin jack × 1

Pb/Pr : 0.7V(p-p), 75

, RCA pin jack × 2

Audio 500mV(rms)(-4dBs), high impedance, RCA pin jack

× 2

Input3 (Front)

Video 1V(p-p), negative sync, 75

, RCA pin jack × 1

Audio 500mV(rms)(-4dBs), high impedance, RCA pin jack

× 2

Input4 (Rear)

Component Video Y : 1V(p-p), negative sync, 75

, RCA pin jack × 1

Pb/Pr : 0.7V(p-p), 75

, RCA pin jack × 2

Audio 500mV(rms)(-4dBs), high impedance, RCA pin jack

× 2

Subwoofer Output (Audio)

More than 0 to 1000mV (rms)(+2.2dBs), low impedance, RCA pin jack

× 1

Audio Output (Fix)

500mV(rms)(-4dBs), low Impedance, (400kHz when modulated 100%),

RCA pin jack

× 2

AV COMPULINK lll

3.5mm mini jack

× 1

Remote Control Unit

RM-C1251G (AA/R6/UM-3 battery

× 2)

(No.52154)1-3

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) Use isolation transformer when hot chassis.

The chassis and any sub-chassis contained in some products are

connected to one side of the AC power line. An isolation

transformer of adequate capacity should be inserted between the

product and the AC power supply point while performing any

service on some products when the HOT chassis is exposed.

(5) 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 differ-

ence of the GND is shown by the LIVE : (

) side GND, the ISOLAT-

ED (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.

(6) 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).

(7) 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.

(8) 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.

(9) 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.

(10) 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 1100V AC

(r.m.s.) for a period of one second.

(. . . . Withstand a voltage of 1100V AC (r.m.s.) to an appliance rat-

ed 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

per volt or more sensitivity in the

following manner. Connect a 1500

10W resistor paralleled by

a 0.15

µF 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.).

(11) High voltage hold down circuit check.

After repair of the high voltage hold down circuit, this circuit shall

be checked to operate correctly.See item "How to check the high

voltage hold down circuit".

AC VOLTMETER

(HAVING 1000 /V,

OR MORE SENSITIVITY)

PLACE THIS PROBE

ON EACH EXPOSED

METAL PART

1500

10W

0.15 F AC-TYPE

GOOD EARTH GROUND

PWB

White line side

WHT

POWER CORD

REPLACEMENT WARNING.

Connecting the white line side of power

cord to "WHT" character side.

This mark shows a fast

operating fuse, the

letters indicated below

show the rating.

1-4 (No.52154)

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

2.1

FEATURES

· New chassis (GJ2) design enables use of a single board with

simplified circuitry.

· Users can make fun to connect the DVD player with the

component video signal input terminal.

· Provided with miniature tuner (TV/CATV).

· Multifunctional remote control permits picture adjustment.

· Adoption of the CHANNEL GUARD function prevents the

specific channels from being selected, unless the "ID number"

is key in.

·I2C bus control utilizes single chip ICs.

· Adoption of the VIDEO STATUS / THEATER PRO. function.

· Adoption of the ON/OFF TIMER and SLEEP TIMER function.

· Built-in V-CHIP system.

· Closed-caption broadcasts can be viewed.

· Built-in AHS (Advanced Hyper Surround) system.

· S-VIDEO input terminal for taking best advantage of Super

VHS.

· Digital Comb filter Improved picture quality.

· Adoption of the ASPECT MODE (4:3/ 16:9) function.

· By pushing the EZ SURF key, Back Program Information can

be displayed in written from program Information uses a CALL

LETTER (broadcasting station ID), a Network name and a

Program name of XDS data, and collectÅfs tuning of the tuner

for PIP one by one.

· Two programs can be displayed on the screen by the 2 tuners

PIP circuit.

(No.52154)1-5

2.2

TECHNINAL INFORMATION

2.2.1 SYSTEM BLOCK DIAGRAM

2.2.2 MAIN MI-COM (CPU) PIN FUNCTION

SCL1

SDA1

AFT1

AFT2

SCL0

SDA0

SCL0

SDA0

SCL0

SDA0

MAIN MI-COM /

VIDEO PROCESS /

DEF. PROCESS

IC4101

SUB IF DET

IC101

MAIN IF DET

TU001

MAIN TUNER

TU4001

SUB TUNER

IC4301

PIP CONTROL

IC5501

SCL0

SDA0

IC5001

MTS

TONE/VOL

SCL0

SDA0

IC5201

3-LINE YC SEP.

SCL0

SDA0

SCL0

SDA0

SCL0

SDA0

IC502

D-A CONVERTER

SCL0

S DA0

IC5701

EXPANSION

I/O

LATCH&

AV SW

IC201

REMOCON

RECEIVER

IC702

MEMORY

Function

No.

Pin name

YCD_GND

Vin1

ABCL

Monitor

Black_Det

SVM_out

APL_Fil

APC_Fil

3.58MHz

YC_Vcc_5V

R_out

G_out

B_out

RGB_Vcc_9V

IK in

TV_DGND

uP_MPAGND

uP_MPAVDD

MAIN_POWER

HAZARD

SDAO

SCLO

SDA1

AGC ADJUST

SCL1

LED

REMOCON

COMPULINK

GND

Not used

Current for automatic beam (brightness)/contrast limit

Clamp pulse (for Component / PIP switch)

Black level detection filter

Y signal for scan velocity modulation

Average picture level filter

Automatc phase control filter

Color sub carrier (3.58MHz) for 3-line digital comb filter [IC5201]

5V (for video process circuit)

R signal

G signal

B signal

9V (for RGB process circuit)

Not used

GND

Power on/off switching control [Powen on : L]

B1 over cuurent / V. amplitude detection (for protect) [Defective : H]

Data for Inter IC control bus (for various devices)

Clock for Inter IC control bus (for various devices)

Data for Inter IC control bus (for main memory)

AGC adjustment (for tuner) <S45 in Service menu>

Clock for Inter IC control bus (for main memory)

POWER / ON TIMER LED lndication [lighting : L]

Remote control sensor input [No input : H]

AV COMPULINK lll control [No input : H]

Function

No.

Pin name

AFT2

AFT1

KEY

uP DVss

Reset

Xout

Xin

TEST

uP_DVDD

AGC_MUTE

UP_VVss

TV_HGND

FBP_SCP

Hout

H_Vcc_9V

HAFC_1

Vsaw

Vout

EW_out

Xray

Cb_input

Y_input

Cr_input

DVcc_3.3V

V3in/Cin

EHT_in

V2in/Y

AFT voltage for sub tuner (Tuning frequency control)

AFT voltage for main tuner (Tuning frequency control)

Key scan for front control [No signal : H]

GND

CPU reset

CPU system clock : 8MHz oscillation

GND

AGC muting for main tuner (when channel select) [Muting : H]

GND

Flyback pulse (H. pulse)

H. drive (oscillation)

9V (for H. oscillation start)

H. AFC filter

V. saw filter

V. drive

Parabola waveform (for sidepin correection)

X-ray detection (for protection) [Detection : H]

PIP area pulse [sub picture on:H]

Cb(external) /B-Y(PIP) signal

Y signal (external /PIP)

Cr(external) /R-Y(PIP) signal

3.3V

Chroma signal (for YC separation output)

Not used

Y signal (for YC separation output)

I/O