JVC AV24F703 - Service Manual Immediate Download

SERVICE MANUAL

AV-24F703

COLOR TELEVISION

No. 52000

Mar. 2002

AV-24F703

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CONTENTS

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

a OPERATING INSTRUCTIONS (APPENDIX)

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

a SPECIFIC SERVICE INSTRUCTIONS ....................................................................................................4

a SERVICE ADJUSTMENTS ......................................................................................................................9

a GUIDE FOR REPAIRING .......................................................................................................................15

a STANDARD CIRCUIT DIAGRAM ........................................................................................................ 2-1

a PARTS LIST ...........................................................................................................................................21

No. 52000

AV-24F703

SPECIFICATIONS

TELEVISION

Picture Tube:

24" (measured diagonally)

Color System:

NTSC

TV RF System:

CCIR (M)

Tuner Type:

181 Channel, Quartz PLL Frequency Synthesized

Receiving Channels:

VHF

2-13

UHF

14-69

CATV

01-97 (5A)-(A-3)

98-99 (A-2)-(A-1)

14-22 (A)-(I)

23-36 (J)-(W)

37-65 (AA)-(FFF)

66-125 (GGG)-(125)

Intermediate Frequency:

Picture (FP) : 45.75 MHz

Sound (FS) : 41.25 MHz

FP-FS :

4.50 MHz

Antenna Input:

VHF/UHF In 75 ohms coaxial, F-Type Connector

Speaker:

2" x 4-3/4", 8 ohms x 2

Audio Output Power:

5 W + 5 W

GENERAL

Power Source:

120 V AC, 60 Hz

Power Consumption:

125 Watts

Dimensions(W x H x D):

26-1/2" (670 mm) x 19-1/8" (484 mm) x 20-1/8" (509 mm)

Weight:

72.6 Ibs/33 kg

Video/Audio Inputs:

Component input

Y input: 1.0 Vp-p, 75 ohm (RCA pin jack)

Pb, Pr input : 0.7 Vp-p, 75 ohm (RCA pin jack)

S-Video input

Y input: 1.0 Vp-p, 75 ohm

C input: 0.3 Vp-p, 75 ohm

Video input:

1.0 Vp-p, 75 ohm (RCA pin jack)

Audio input:

-8dB, 47 kohm (RCA pin jack)

Headphone Jack:

3.5 mm mini-jack

Storage Temperature

-20 °C ~ 60 °C

Operating Temperature

5 °C ~ 40 °C

Accessories:

Remote Control X 1

Batteries (UM-3) X 2

Design & specification are subject to change without notice.

AV-24F703

No. 52000

SAFETY PRECAUTIONS

SERVICING NOTICES ON CHECKING

6. AVOID AN X-RAY

1. KEEP THE NOTICES

As for the places which need special attentions,

they are indicated with the labels or seals on the

cabinet, chassis and parts. Make sure to keep the

indications and notices in the operation manual.

3. USE THE DESIGNATED PARTS

5. TAKE CARE TO DEAL WITH THE

CATHODE-RAY TUBE

Safety is secured against an X-ray by consider-

ing about the cathode-ray tube and the high

voltage peripheral circuit, etc.

Therefore, when repairing the high voltage pe-

ripheral circuit, use the designated parts and

make sure not modify the circuit.

Repairing except indicates causes rising of high

voltage, and it emits an X-ray from the cathode-

ray tube.

Please include the following informations when you order parts. (Particularly the VERSION LETTER.)

1. MODEL NUMBER and VERSION LETTER

The MODEL NUMBER can be found on the back of each product and the VERSION LETTER can be

found at the end of the SERIAL NUMBER.

2. PART NO. and DESCRIPTION

You can find it in your SERVICE MANUAL.

HOW TO ORDER PARTS

Inferior silicon grease can damage IC's and transistors.

When replacing an IC's or transistors, use only specified silicon grease (YG6260M).

Remove all old silicon before applying new silicon.

IMPORTANT

2. AVOID AN ELECTRIC SHOCK

There is a high voltage part inside. Avoid an

electric shock while the electric current is

flowing.

The parts in this equipment have the specific

characters of incombustibility and withstand

voltage for safety. Therefore, the part which is

replaced should be used the part which has

the same character.

Especially as to the important parts for safety

which is indicated in the circuit diagram or the

table of parts as a

mark, the designated

parts must be used.

4. PUT PARTS AND WIRES IN THE

ORIGINAL POSITION AFTER

ASSEMBLING OR WIRING

There are parts which use the insulation

material such as a tube or tape for safety, or

which are assembled in the condition that

these do not contact with the printed board.

The inside wiring is designed not to get closer

to the pyrogenic parts and high voltage parts.

Therefore, put these parts in the original

positions.

In the condition that an explosion-proof cathode-

ray tube is set in this equipment, safety is

secured against implosion. However, when

removing it or serving from backward, it is

dangerous to give a shock. Take enough care to

deal with it.

PERFORM A SAFETY CHECK AFTER

SERVICING

Confirm that the screws, parts and wiring which

were removed in order to service are put in the

original positions, or whether there are the

portions which are deteriorated around the

serviced places serviced or not. Check the

insulation between the antenna terminal or

external metal and the AC cord plug blades.

And be sure the safety of that.

(INSULATION CHECK PROCEDURE)

Unplug the plug from the AC outlet.

Remove the antenna terminal on TV and turn

on the TV.

Insulation resistance between the cord plug

terminals and the eternal exposure metal

[Note 2] should be more than 1M ohm by

using the 500V insulation resistance meter

[Note 1].

If the insulation resistance is less than 1M

ohm, the inspection repair should be

required.

[Note 1]

If you have not the 500V insulation

resistance meter, use a Tester.

[Note 2]

External exposure metal: Antenna terminal

Earphone jack

Licensed by BBE Sound, Inc. under USP4638258 and 4482866.

BBE and BBE symbol are registered trademarks of BBE

Sound, Inc.

No. 52000

AV-24F703

Rubber Cap

CRT

Support

GND on the CRT

Screwdriver

Alligator Clip

Support

CRT

GND on the CRT

1. REMOVAL OF ANODE CAP

Read the following NOTED items before starting work.

After turning the power off there might still be a potential

voltage that is very dangerous. When removing the

Anode Cap, make sure to discharge the Anode Cap's

potential voltage.

Do not use pliers to loosen or tighten the Anode Cap

terminal, this may cause the spring to be damaged.

REMOVAL

1. Follow the steps as follows to discharge the Anode Cap.

(Refer to Fig. 1-1.)

Connect one end of an Alligator Clip to the metal part of a

flat-blade screwdriver and the other end to ground.

While holding the plastic part of the insulated Screwdriver,

touch the support of the Anode with the tip of the

Screwdriver.

A cracking noise will be heard as the voltage is discharged.

Flip up the sides of the Rubber Cap in the direction of the

arrow and remove one side of the support.

(Refer to Fig. 1-2.)

Fig. 1-1

Fig. 1-2

3. After one side is removed, pull in the opposite direction to

remove the other.

NOTE

DISASSEMBLY INSTRUCTIONS

INSTALLATION

1. Clean the spot where the cap was located with a small

amount of alcohol. (Refer to Fig. 1-3.)

NOTE

Confirm that there is no dirt, dust, etc. at the spot where

the cap was located.

Arrange the wire of the Anode Cap and make sure the

wire is not twisted.

Turn over the Rubber Cap. (Refer to Fig. 1-4.)

Fig. 1-4

4. Insert one end of the Anode Support into the anode

button, then the other as shown in Fig. 1-5.

CRT

Support

Fig. 1-5

Confirm that the Support is securely connected.

Put on the Rubber Cap without moving any parts.

Location of Anode Cap

Fig. 1-3

Take care not to damage the Rubber Cap.

SPECIFIC SERVICE INSTRUCTIONS

AV-24F703

No. 52000

DISASSEMBLY INSTRUCTIONS

2. REMOVAL AND INSTALLATION OF FLAT

PACKAGE IC

REMOVAL

1. Put the Masking Tape (cotton tape) around the Flat

Package IC to protect other parts from any damage.

(Refer to Fig. 2-1.)

NOTE

Masking is carried out on all the parts located within

10 mm distance from IC leads.

Fig. 2-1

Masking Tape

(Cotton Tape)

2. Heat the IC leads using a blower type IC desoldering

machine. (Refer to Fig. 2-2.)

NOTE

Do not add the rotating and the back and forth direc-

tions force on the IC, until IC can move back and forth

easily after desoldering the IC leads completely.

Fig. 2-2

Blower type IC

desoldering machine

3. When IC starts moving back and forth easily after

desoldering completely, pickup the corner of the IC using

a tweezers and remove the IC by moving with the IC

desoldering machine. (Refer to Fig. 2-3.)

NOTE

Some ICs on the PCB are affixed with glue, so be

careful not to break or damage the foil of each IC

leads or solder lands under the IC when removing it.

Fig. 2-3

Blower type IC

desoldering machine

Tweezers

Peel off the Masking Tape.

Absorb the solder left on the pattern using the Braided

Shield Wire. (Refer to Fig. 2-4.)

NOTE

Do not move the Braided Shield Wire in the vertical

direction towards the IC pattern.

Fig. 2-4

Braided Shield Wire

Soldering Iron

IC pattern