JVC AV-27260/AR, AV-27260/AS, AV-27260/AZ Service Manual

SERVICE MANUAL

COLOR TELEVISION

AV-27260

BASIC CHASSIS

AV-27260 AV-27260

AV-27260

/AR

/AS

/AZ

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

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

a FEATURES ..............................................................................................................................................4

a MAIN DIFFERENCE LIST........................................................................................................................5

a HOW TO IDENTIFY MODELS ..................................................................................................................5

a FUNCTIONS .............................................................................................................................................6

a SPECIFIC SERVICE INSTRUCTIONS ....................................................................................................7

a SERVICE ADJUSTMENTS ....................................................................................................................12

¤ STANDARD CIRCUIT DIAGRAM (APPENDIX) .................................................................................. 2-1

a PARTS LIST ...........................................................................................................................................31

No. 51800C

Dec. 2001

AV-27260

SPECIFICATIONS

Items Contents

Dimensions (W × H × D)

················································································································································································································

Mass

TV RF System

Color Sound System

TV Receiving Channels and Frequency

VL Band

VH Band

UHF Band

CATV Receiving Channels and Frequency

Low Band

High Band

Mid Band

Super Band

Hyper Band

Ultra Band

Sub Mid Band

TV/CATV Total Channel

Intermediate Frequency

Video IF Carrier

Sound IF Carrier

Color Sub Carrier

Power Input

Power Consumption

Picture Tube

High Voltage

Speaker

Audio Power Output

Video / Audio Input (1 / 2 / 3)

25-3/4” × 23-3/8” × 20-1/2” / 65.4cm × 59.1cm × 51.6cm

74.8 Ibs/34.0kg

CCIR(M)

NTSC, BTSC System (Multi Channel Sound)

(02~06) 54MHz~88MHz

~13) 174MHz~216MHz

(07

(14

~69) 470MHz~806MHz

(02~06, A-8) by (02~06&01)

(07~13) by (07~13)

(A~1) by (14~22)

(J~W) by (23~36) (54MHz~804MHz)

(W+1~W+28) by (37~64)

(W+29~W+84) by (65~125)

(A8, A4~A1) by (01, 96~99)

180 Channels

45.75MHz

41.25MHz (4.5MHz)

3.58MHz

120V AC, 60Hz

123W

27” (68cm) Measured Diagonally

29kV±1.3kV (at zero beam current)

2” × 4-3/4” / 5 × 12cm Oval type × 2

3W × 2

Video(1,3) : 1Vp-p, 75Ø (RCA pin jack)

Audio(1,2,3) : 500mVrms ( -4dBs ), High Impedance (RCA pin jack)

S-Video ( Input 1 Over )

Y : 1Vp-p Positive (negative sync provided, when terminated with 75Ø)

C : 0.286Vp-p (burst signal, when terminated with 75Ø)

Component Input ( Input 2 )

Y : 1Vp-p positive (negative sync provided, when terminated with 75Ø)

PB/PR : 0.7Vp-p 75 Ø

—

Audio Output

(Variable)

AV Compu link EX Input

Antenna terminal

Remote Control Unit

Variable : More then 0~1550mVrms (+6dBs)

Low impedance (400Hz when modulated 100%)

3.5mm mini jack

75Ø(VHF/UHF) Terminal, F-Type Connector

RM-C305-1A

(AA/R6/UM-3 battery × 2)

(RCA pin jack)

Design & specifications are subject to change without notice.

2 No. 51800C

GOOD EARTH GROUND

0.15 µF AC-TYPE

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

PLACE THIS PROBE ON EACH EXPOSED METAL PART

1500Ø 10W

A V

This mark shows a fast

POWER CORD REPLACEMENT WARNING

Connecting the white line side of power cord to “WHT” character side.

operating fuse, the letters indicated below show the rating.

PWB

WHT

White line side

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 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.

6. 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).

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 10kØ 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.

No. 51800C 3

AV-27260

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, screwheads, earphone jack, control shafts, etc.) to be sure the product is safe to operate without danger of electrical shock.

(1) 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 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.

(2) 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 1500Ø 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.).

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”.

AV-27260

FEATURES

Full-square CRT (cathode ray tube) reproduces fine textured pic-

•

ture in every detail. I2C bus control utilizes single chip ICs.

•

Built in Twin Tuner system.

•

Built-in HYPER-SURROUND system.

•

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

•

3 LINE DIGITAL COMB FILTER circuit improved picture quality.

•

a SYSTEM BLOCK DIAGRAM

IC702

EEPROM 4k bit

SCL 1 SDA 1

Component input terminal for talking best advantage of Component

•

Video Signal. Audio Video input terminal. (S-input ×1, V-input ×2)

•

Variable audio output terminal.

•

Closed-caption broadcasts can be viewed.

•

With AV COMPU LINK EX terminal.

•

IF2

AFT2

Remote

control

unit

IC301

PIP

CONTROL

SCL 0 SDA 0

IC701

MAIN MICON

IC101

1 CHIP

CONTROL

TU001

TUNER 1

AFT1

TU001

TUNER 2

IC001

MTS, TONE

SURROUND CONTROL

4 No. 51800C

MAIN DIFFERENCE LIST

AV-27260

Part name

MAIN PWB SGC-1020A-M2 SGC-1025A-M2 SGC-1019A-M2

CRT SOCKET PWB SGC-3002A-M2 SGC-3001A-M2 SGC-3009A-M2

! PICTURE TUBE A68ADT25X01 A68QDN891X001 A68AJB82X02

Model

AV-27260/AR AV-27260/AS AV-27260/AZ

HOW TO IDENTIFY MODELS

The difference between AV-27260/AR, AV-27260/AS and AV-27260/AZ is in the PICTURE TUBE. As the result of the difference in PICTURE TUBE, the MAIN PWB also differ.

Part name

! RATING LABEL LC31139-001A-A

------------------------------------------------------------------------------------------------------------------------------

Model

AV-27260/AR AV-27260/AS AV-27260/AZ

INDICATED AV-27260

INDICATED “AR”

INDICATED “AS”

INDICATED “AZ”

No. 51800C 5

AV-27260

FUNCTIONS

a FRONT PANEL

a REAR PANEL

VIDEO

INPUT3

AUDIO

L/MONO R

CHANNEL

OPERATE

VOLUME

POWER

ON TIMER

a REMOTE CONTROL UNIT

(RM-C305-1A)

CATV

VCR

CHANNEL

FREEZE

PIP

DVD

100+

ON/MOVE

SWAP

POWER

RETURN+

INPUT

SOURCE

VIDEO STATUS

DISPLAY

SLEEP TIMER

HYPER SURROUND

RM-C305

MUTING

VOL

V CHIP

VOL

VCR/DVD

POWER

PIP OFF

TV/VCR

PAUSE

VCR CHANNEL

PREV NEXT

PLAY FFREW

REC STOP

OPEN/CLOSE STILL/PAUSE

EXIT

6 No. 51800C

SPECIFIC SERVICE INSTRUCTIONS

DISASSEMBLY PROCEDURE

AV-27260

REMOVING THE REAR COVER

1. Unplug the power supply cord.

2. Remove the 9 screws marked A as shown in Fig.1.

3. Withdraw the REAR COVER toward you.

[CAUTION]

When reinstalling the rear cover, carefully push it inward after in-

•

serting the MAIN PWB into the rear cover groove.

REMOVING THE CHASSIS

After removing the rear cover.

•

1. Slightly raise the both sides of the chassis by hand and remove the 3 claws marked B under the chassis from the front cabinet as shown in Fig.1.

2. Withdraw the chassis backward along the rail in the arrow direction marked C as shown in Fig.1.

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

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.

REMOVING THE TERMINAL BOARD

After removing the rear cover.

•

1. Remove the 4 screws marked D as shown in Fig.1.

2. When you pull out the TERMINAL BOARD in the direction of arrow marked E as shown in Fig.1, it can be removed.

REMOVING THE SPEAKER

After removing the rear cover.

•

1. Remove the 2 screws marked H as shown in Fig.1.

2. Withdraw the speaker backward.

3. Follow the same steps when removing the other hand speaker.

CHECKING THE MAIN PW BOARD

1. To check the back side of the MAIN PW Board.

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 PW Board.

[CAUTION]

When erecting the chassis, be careful so that there will be no con-

•

tacting with other PW Board. Before turning on power, make sure that the CRT earth wire and

•

other connectors are properly connected.

WIRE CLAMPING AND CABLE TYING

1. Be sure 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.

REMOVING THE FRONT CONTROL AND FRONT AV INPUT PW BOARDS

After removing the rear cover and chassis.

•

1. Remove the 2 screws marked F and the 2 screws marked G as shown in Fig.1.

2. Then remove the FRONT CONTROL PWB and FRONT AV INPUT PWB.

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

No. 51800C 7

AV-27260

FRONT CABINET

PICTURE TUBE

CRT SOCKET PWB

SPEAKER

(x2)

REAR COVER

(x2)

FRONT AV INPUT PWB

CLAW

(x2)

FRONT

(x2)

CONTROL PWB

CLAW

AV SELECTOR PWB

PIP PWB

MAIN PWB

CHASSIS BASE

(x4)

(x2)

Fig.1

8 No. 51800C

(x7)

MEMORY IC REPLACEMENT

1. Memory IC

This model use a memory IC. This memory IC stores data for proper operation of the video and deflection circuits. When replacing, be sure to use an IC containing this (initial value) data.

2. Memory IC replacement procedure

Procedure Screen display

(1) Power off

Switch off the power and disconnect the power cord from the outlet.

(2) Replace the memory IC

Initial value must be entered into the new IC.

(3) Power on

Connect the power cord to the outlet and switch on the power.

AV-27260

(4) System constant check and setting

1) Press SLEEP TIMER key and, while the indication of “SLEEP TIMER 0 MIN.” is being displayed, press DISPLAY key and VIDEO STATUS

key on the remote control unit simultaneously.

2) The SERVICE MENU screen of Fig.1 is displayed.

3) While the SERVICE MENU is displayed, again simultaneously press the DISPLAY and VIDEO STATUS keys to display the Fig.2 SYSTEM CONSTANT screen.

4) Refer to the SYSTEM CONSTANT table and check the setting items. Where these differ, select the setting item with the MENU UP/DOWN key and adjust the setting with the MENU LEFT/RIGHT keys. (The letters of the selected item are displayed in yellow.)

5) After adjusting, release the MENU LEFT/RIGHT key to store the setting value.

6) Press the EXIT key twice to return the normal screen.

(5) Receive channel setting

Refer to the OPERATING INSTRUCTIONS(USER'S GUIDE) and set the receive channels (Channels Preset) as described.

(6) User settings

Check the user setting items according to Table 2. Where these do not agree, refer to the OPERATING INSTRUCTIONS (USER'S GUIDE) and set the items as described.

SERVICE MENU

PICTURE SOUND THEATER OTHERS PIP LOW LIGHT HIGH LIGHT RF AFC1 RF AFC2 TU2 VCO I2C BUS CTRL

SELECT BY OPERATE BY

Fig.1

SYSTEM CONSTANT

MODEL :99– CCD : YES V-CHIP : YES CAN V-CHIP : YES

EXIT BY

99999

999999999 999

SELECT BY OPERATE BY

Fig.2

EXIT BY

EX IT

(7) SERVICE MENU setting

Verify what to set in the SERVICE MENU, and set whatever is necessary.(Fig.1) Refer to the SERVICE ADJUSTMENT for setting.

No. 51800C 9

AV-27260

TABLE 1 (System Constant setting)

Setting item Setting content Setting value

AV-36230A AV-32D502AAV-27D502A

MODEL AV-27260A

AV-36D302A AV-32D302A AV-36D502A

AV-32D202A AV-36D202A AV-27260A

AV-32230A AV-36260A AV-32260A

CCD

V-CHIP

CAN V-CHIP

YES NO

TABLE 2 (User setting value)

Setting item Setting value

1. Use remote controller keys

POWER OFF CHANNEL CH-02 VOLUME 5 INPUT TV HYPER SURROUND OFF DISPLAY OFF SLEEP TIMER 0 VIDEO STATUS CHOICE PIP SOURCE CH-04 PIP ON (PIP POSITION) LEFT LOWER SIDE

2. Setting of MENU

PICTURE ADJUST

TINT CENTER COLOR CENTER PICTURE CENTER BRIGHT CENTER DETAIL CENTER NOISE MUTING ON SET VIDEO STATUS ALL CENTER

YES

SOUND ADJUST

BASS CENTER TREBLE CENTER BALANCE CENTER MTS STEREO

CLOCK/TIMERS

SET CLOCK Unnecessary to set ON/OFF TIMER NO

INITIAL SETUP

TV SPEAKER ON LANGUAGE ENG CLOSED CAPTION OFF AUTO TUNER SETUP TUNER MODE: AIR CHANNEL SUMMARY Unnecessary to set V-CHIP OFF SET LOCK CODE Unnecessary to set

10 No. 51800C

+ 21 hidden pages

JVC AV-27260/AR, AV-27260/AS, AV-27260/AZ Service Manual

CONTENTS

SPECIFICATIONS

SAFETY PRECAUTIONS

FEATURES

MAIN DIFFERENCE LIST

HOW TO IDENTIFY MODELS

FUNCTIONS

SPECIFIC SERVICE INSTRUCTIONS