JVC AV-27F475/S, AV-27F475/Z, AV-27F485/S, AV-27F485/Z Service Manual

SERVICE MANUAL

COLOR TELEVISION

YA05320043

AV-27F475 /S, AV-27F475 /Z, AV-27F485

/S, AV-27F485 /Z

BASIC CHASSIS

GJ4

TABLE OF CONTENTS

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

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

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

4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11

5 TROUBLE SHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-27

No.YA053

2004/3

SPECIFICATION

Items

Dimensions (W × H × D) 82.9 cm × 59.3 cm × 51.9cm (32-5/8" × 23-3/8" × 20-1/2")

Mass 43.0kg (94.6Ibs)

TV RF System CCIR (M)

Color System NTSC

Sound System BTSC (Multi Channel Sound)

TV Receiving Channels and Frequency

TV / CATV Total Channel 180 Channels

Intermediate Frequency Video IF

Color Sub Carrier 3.58 MHz

Power Input AC120V, 60Hz

Power Consumption 140W

Picture Tube (Visible size) 68cm (27”) Measured diagonally (H : 54.4cm × W : 41.8cm)

High Voltage 30.0kV ±1.3kV [at Zero beam current]

Speaker 6.5cm × 13cm (2-1/2" × 5"), Oval type × 2

Audio Power Output 7.5W + 7.5W 9W + 9W

Antenna Terminal (VHF / UHF) F-type connector, 75 Ω unbalanced

Video / Audio input Input-1/2/3

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

Remote Control Unit RM-C1258G (AA/R6/UM-3 battery × 2)

Component Video

VHF low

VHF high

UHF

CATV

Sound IF

[Input-2]

S-video

[Input-1]

Video Audio

02ch~06ch : 54MHz~88MHz 07ch~13ch : 174MHz~216MHz 14ch~69ch : 470MHz~806MHz 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

45.75 MHz

41.25 MHz (4.5MHz)

RCA pin jack × 3 Y : 1V(p-p), negative sync, 75 Ω Pb/Pr : 0.7V(p-p), 75 Ω Mini DIN 4-pin × 1 Y : 1V(p-p), negative sync, 75 Ω C : 0.286V(p-p)(burst signal), 75 Ω 1V(p-p), negative sync, 75 Ω, RCA pin jack × 3 500mV(rms)(-4dBs), high impedance, RCA pin jack × 6

RCA pin jack × 2

AV-27F475 AV-27F485

Contents

Design & specifications are subject to change without notice.

1-2 (No.YA053)

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 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 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 10kΩ 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 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

(11) High voltage hold down circuit check.

GOOD EARTH GROUND

ON EACH EXPOSED ME TAL PA RT

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".

This mark shows a fast operating fuse, the letters indicated below show the rating.

A V

POWER CORD REPLACEMENT WARNING.

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

PWB

White line side

WHT

(No.YA053)1-3

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

2.1 FEATURES

SMART CAPTION [AV-27F485]

Smart caption will appear when you press the MUTING button, only on channels where the broadcast contains CLOSED CAPTION information.

SMART SOUND

Decreases high sound levels, giving a regulated sound level.

FLAT SQUARE CRT

It became legible from any position by CRT with few reflection and reflect lumps on the flat screen.

DIGITAL COMB FILTER

By the 3 line digital comb filter, the refreshed image can be seen.

VIDEO STATUS

Expression of a favorite screen can be chosen by the VIDEO STATUS function.

[STANDARD ↔ DYNAMIC ↔ THEATER ↔ GAME]

COMPONENT INPUT

Since the component signal input terminal is equipped, it reappears direct without deteriorating the signal from DVD.

V-CHIP

Since the V-CHIP is built in, it can choose, view and listen to a healthy program.

MTS STEREO

The voice multiplex function of the MTS system is built in. (MTS = Multi channel Television Sound system)

RETURN PLUS

You program a specific channel to return to while scanning through the channels using the CH+ and CH - keys.

VIDEO INPUT LABEL

This function is used to label video input connections for the onscreen displays.

WORLD CLOCK

The world clock feature provides time differences for some of the major cities around the world in real time.

BBE

High definition audio adds natural, clear and extraordinary sound quality to any program.

A.H.S. [AV-27F485]

Adds a more spacious surround sound. Music gives basic effect and Movie for more effect.

HYPER SURROUND [AV-27F475]

Creates a deep, three-dimensional sound effect by channeling the audio through the TV's front-firing speakers.

2.2 HOW TO IDENTIFY MODELS

How to recognize from the appearance of the model concerned is written below. Please distinguish from several contents currently printed on the rating label

MODEL NAME

AV-27F475

AC 120V 60Hz

MODEL NO.

TV SCREEN SIZE : DIAGONAL

CHASSIS NO. MANUFACTURED SERIAL NO.

INCHES

VIDEO EQUIPMENT

4C43

AV-27F485

DISTINGUISH NAME

2.3 MAIN DIFFERENCE LIST

The difference between S models and Z models are in the PICTURE TUBE.

Item AV-27F475/S AV-27F475/Z AV-27F485/S AV-27F485/Z

PICTURE TUBE (ITC) A68QCP693X003 A68QCU770X78N A68QCP693X003 A68QCU770X78N

SMART CAPTION NO ← YES ← A.H.S. NO ← YES ← HYPER SURROUND YES ← NO ←

1-4 (No.YA053)

2.4 TECHNICAL INFORMATION

2.4.1 SYSTEM BLOCK DIAGRAM

REMOCON RECEIVER

IC702

MEMORY

SCL0 SDA0

IC5001

MTS

TONE/VOL

REMOCON

IC201

MAIN MI-COM /

SCL1

SDA1

SCL0 SDA0 SCL0 SDA0

VIDEO PROCESS /

DEF. PROCESS

SCL0 SDA0

IC5501

LATCH& AV SW

IC5201

3-LINE YC SEP.

AFT1

SCL0 SDA0

TU001

TUNER

IC101

IF DET

SCL0 SDA0

IC502

D-A CONVERTER

2.4.2 MAIN MI-COM (CPU) PIN FUNCTION

Pin name I/O Function

No.

1 MTS_ADJ I Not used 29 YC_GND - GND

2 AFT1 I AFT voltage for tuner (Tuning frequency control) 30 V1_IN I Not used

3 KEY I Key scan for front control [No signal : H] 31 ABCL I Current for automatic beam (brightness)/contrast limit

4 uP_DVss - GND 32

5 Reset I CPU reset 33 BLACK_DET - Black level detection filter

6 8MHz_OUT O CPU system clock : 8MHz oscillation 34 SVM_OUT O Y signal for velocity scan modulation

7 8MHz_IN I CPU system clock : 8MHz oscillation 35 APL_FIL - Average picture level filter

8 TEST - GND 36 APC_FIL - Automatic phase control filter

9 uP_DVD D - 5V 37 fsc_OUT O Color sub carrier (3.58MHz) for 3-line digital comb filter [IC5201]

10 AGC_MUTE O AGC muting for tuner (when channel select) [Muting : H] 38 YC_Vcc - 5V (for video process circuit)

11 uP_VVSS - GND 39 R_OUT O R signal

12 TV_HGND - GND 40 G_OUT O G signal

13 FBP_SCP I Flyback pulse (H. pulse) 41 B_OUT O B signal

14 HOUT O H. drive (oscillation) 42 RGB_Vcc - 9V (for RGB process circuit)

15 H_Vcc - 9V (for H. oscillation start) 43 IK_IN I Not used

16 HAFC_1 - H. AFC filter 44 TV_DGND - GND

17 Vsaw - V. saw filter 45 uP_AGND - GND

18 VOUT O V. drive 46 uP_AVdd - 5V

19 EW_OUT O Parabola waveform (for sidepin correection) 47 MAIN_POWER O Power on/off switching control [Powen on : L]

20 X-RAY I X-ray detection (for protection) [Detection : H] 48 PANORAMA I Not used

21 Ys I Not used 49 SDAO I/O Data for Inter IC control bus (for various devices)

22 Cb_IN I Cb (external) signal 50 SCLO O Clock for Inter IC control bus (for various devices)

23 Y_IN I Y (external) signal 51 SDA1 I/O Data for Inter IC control bus (for main memory)

24 Cr_IN I Cr (external) signal 52 A_MUTING O Audio muting [Muting : H]

25 TV_DVcc - 3.3V 53 SCL1 O Clock for Inter IC control bus (for main memory)

26 V3IN/CIN I Chroma signal (for YC separation output) 54 LED O POWER / ON TIMER LED lndication [lighting : L]

27 EHT_IN I Not used 55 REMOCON I Remote control sensor input [No input : H]

28 V2_IN/Y_IN I Y signal (for YC separation output) 56 ASP_ABL I Not used

Pin name I/O Function

No.

MONITOR_OUT

O Not used

(No.YA053)1-5

SECTION 3

DISASSEMBLY

3.1 DISASSEMBLY PROCEDURE

3.1.1 REMOVING THE REAR COVER

(1) Disconnect the power plug. (2) Remove the 11 screws [A]. (3) Withdraw the REAR COVER backward.

3.1.2 REMOVING THE AV TERMINAL BOARD

• Remove the REAR COVER. (1) Remove the 5 screws [B]. (2) Withdraw the AV TERMINAL BOARD toward you.

3.1.3 REMOVING THE CHASSIS

• Remove the REAR COVER.

• Remove the AV TERMINAL BOARD. (1) Slightly raise the both sides of CHASSIS by hand. (2) Remove the 2 claws under the both side of the CHASSIS

from the front cabinet.

(3) Withdraw the CHASSIS backward.

(If necessary, remove the wire clamp, connectors etc.)

3.1.7 CHECKING THE CHASSIS

To check the PW Board from back side.

(1) Pull out the CHASSIS (refer to REMOVING THE CHASSIS). (2) Erect the CHASSIS vertically with the HVT side facing up

so that you can easily check the back side of the PW board.

CAUTION :

• When erecting the CHASSIS, be careful so that there will be no contacting with other PW Board.

• Before turning on power, make sure that the wire connector is properly connected.

• When conducting a check with power supplied, be sure

to confirm that the CRT EARTH WIRE (BRAIDED ASS'Y) is connected to the CRT SOCKET PWB.

3.1.8 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.

3.1.4 REMOVING THE SPEAKER

• Remove the REAR COVER. (1) Remove the 2 screws [C]. (2) Remove the 2 screws [D] and remove the SPEAKER. (3) Follow the same steps when removing the other hand

SPEAKER.

NOTE :

When remove the 2 screws [C] of the SPEAKER, remove the lower side screw first, and then remove the upper one.

3.1.5 REMOVING THE LED & POWER SW PWB

• Remove the REAR COVER. (1) Remove the 2 screws [E]. (2) Withdraw the LED & POWER SW PWB toward you.

*If necessary, remove the wire clamp, connector etc.

3.1.6 REMOVING THE FRONT CONTROL PWB

• Remove the REAR COVER. (1) Remove the 2 screws [F]. (2) Withdraw the FRONT CONTROL PWB toward you.

*If necessary, remove the wire clamp, connector etc.

1-6 (No.YA053)

FRONT CABINET

SPEAKER

LED & POWER SW PWB

CLAW

CRT SOCKET PWB

FRONT CONTROL PWB

CLAW

AV SELECTOR PWB

SPEAKER HOLDER

MAIN PWB

POWER CORD

AV TERMINAL BOARD

REAR COVER

Fig.1

(No.YA053)1-7

3.2 MEMORY IC REPLACEMENT

• This model uses the memory IC.

• This memory IC stores data for proper operation of the video and drive circuits.

• When replacing, be sure to use an IC containing this (initial value) data.

3.2.1 MEMORY IC REPLACEMENT PROCEDURE

1. Power off

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

2. Replace the memory IC

Be sure to use a memory IC written with the initial setting data.

3. Power on

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

4. Receiving channel setting

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

5. User settings

Check the user setting items according to the "FACTORY SETTING ITEM" table. Where these do not agree, refer to the OPERATING INSTRUCTIONS (USER'S GUIDE) and set the items as described.

6. SERVICE MODE setting

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

3.2.2 SERVICE MODE SETTING ITEMS

SERVICE MENU

SERV ICE MENU

V/C(S)

SOUND(A)

3L Y/C(LYC)

LOW LIGHT

VCO

11.

I2C BUS

SELECT BY OPERATE BY

DEF(D)

OTHERS(F)

HIGH LIGHT

12.

SYSTEM(SYS)

EXIT BY

Fig.1

Setting items Settings Item No.

1. V/C

(Video setting)

2. DEF

(Deflection setting)

3. SOUND(A) (Audio setting)

4. OTHERS [Do not adjust] (Factory setting)

5. 3L Y/C [Do not adjust] (Y/C Separate setting)

7. LOW LIGHT

(White balance setting)

8. HIGH LIGHT (White balance setting)

9. VCO

(VCO setting)

11. I2C BUS [Do not adjust]

C BUS setting)

12.SYSTEM (SYS)

(System constant setting)

Adjust S01~S48

Adjust D01~D33

Adjust A01~A08

Fixed F01~F18

Fixed LYC01~LYC12

Adjust ---

Fixed ---

Fixed SYS01~SYS25

EXIT

1-8 (No.YA053)

3.2.3 SETTINGS OF FACTORY SHIPMENT

3.2.3.1 BUTTON OPERATION 3.2.3.2 REMOTE CONTROL DIRECT OPERATION

Setting item Setting position

POWER Off

CHANNEL CH-02

VOLUME 10

3.2.3.3 REMOTE CONTROL MENU OPERATION

(1) PICTURE ADJUST

Setting item Setting position

TINT 0

COLOR 0

PICTURE +8

BRIGHT 0

DETAIL +8

COLOR TEMPERATURE HIGH

NOISE MUTING ON

VSM ON

(2) SOUND ADJUST

Setting item Setting position

BASS 0

TREBLE 0

BALANCE 0

MTS STEREO

SMART SOUND OFF

INPUT TV

CHANNEL CH-02

VOLUME 10

MUTING OFF

DISPLAY OFF

OFF TIMER OFF

THEATER PRO OFF

VIDEO STATUS DYNAMIC

ASPECT 4:3

SOUND

(3) CLOCK / TIMERS

SET CLOCK OFF

ON / OFF TIMER OFF

WORLD CLOCK Refer to OPERATING

(4) INITIAL SETUP

LANGUAGE ENG.

CLOSED CAPTION OFF

FRONT PANEL LOCK OFF

AUTO SHUT OFF OFF

XDS ID ON

VIDEO INPUT LABEL Refer to OPERATING

V-CHIP OFF

Setting item Setting position

A.H.S OFF [AV-27F485]

HYPER SURROND OFF [AV-27F475]

BBE ON

Setting item Setting position

INSTRUCTIONS

Setting item Setting position

INSTRUCTIONS

(No.YA053)1-9

+ 19 hidden pages