JVC AV-27F476/R, AV-27F476/S, AV-32F476/Y, AV-32F476/Z Service Manual

SERVICE MANUAL

COLOR TELEVISION

YA24320052

AV-27F476/R, AV-27F476/S,
AV-32F476

/Y, AV-32F476/Z

BASIC CHASSIS

GJ5

TABLE OF CONTENTS

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

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

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

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

5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-27

COPYRIGHT © 2005 Victor Company of Japan, Limited

No.YA243

2005/2

SPECIFICATION

Items

Dimensions (W × H × D) 82.9 cm × 59.3 cm × 51.9 cm

(32-3/4" × 23-3/8" × 20-1/2")

Mass 43.0 kg (94.6 Ibs) 64.0 kg (140.8 Ibs)

TV RF System CCIR (M)

Color System NTSC

Sound System BTSC (Multi Channel Sound)

Teletext System Closed Caption (T1 - T4 / CC1 - CC4)

TV Receiving Channels
and Frequency

TV / CATV Total Channel 181 Channels

Intermediate Frequency Video IF

Color Sub Carrier 3.58 MHz

Power Input AC120 V, 60 Hz

Power Consumption 140 W 160 W

Picture Tube (Visible size) 68 cm (29") Measured diagonally

High Voltage 30.0 kV ±1.3 kV [at Zero beam current] 31.4 kV ±1.3 kV [at Zero beam current]

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

Audio Power Output 9 W + 9 W

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

Video / Audio input
[Input-1/2/3]

Audio Output (Fix) 500 mV(rms)(-4dBs), low Impedance, (400 kHz when modulated 100 %), RCA pin jack × 2
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: 54 MHz - 88 MHz
07ch - 13ch: 174 MHz - 216 MHz
14ch - 69ch: 470 MHz - 806 MHz
54MHz - 804 MHz
Low Band: 02 - 06
High Band: 07 - 13
Mid Band: 14 - 22
Super Band: 23 - 36
Hyper Band: 37 - 64
Ultra Band: 65 - 94, 100 - 135
Sub Mid Band: 01, 96 - 99

[Reception of channel A-5 ("95" of the TV set’s on-screen CABLE channel) is
recommended for your TV set.]

45.75 MHz

41.25 MHz (4.5 MHz)

(H: 55.4 cm × V: 41.8 cm)

RCA pin jack × 3
Y : 1V(p-p), 75 Ω, negative sync
Pb/Pr : 0.7 V(p-p), 75 Ω
Mini DIN 4-pin connector × 1
Y : 1 V(p-p), 75 Ω, negative sync
C : 0.286 V(p-p)(burst signal), 75 Ω
1 V(p-p), 75 Ω, negative sync, RCA pin jack × 2
500 mV(rms)(-4dBs), high impedance, RCA pin jack × 6

AV-27F476 AV-32F476

Contents

93.9 cm × 68.5 cm × 57cm
(37" × 27" × 22-1/2")

80 cm (34") Measured diagonally

(H: 65.6 cm × V : 49.6 cm)

Design & specifications are subject to change without notice.

1-2 (No.YA243)

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 10k

(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.

Ω 2W resistor to the anode button.

(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
following manner. Connect a 1500
a 0.15

µF AC-type capacitor between an exposed metal part

Ω per volt or more sensitivity in the

Ω 10W resistor paralleled by

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 PAR T

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

PW

(No.YA243)1-3

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

2.1 FEATURES

SMART CAPTION

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.

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.

HYPER SURROUND

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

2.2 MAIN DIFFERENCE LIST

Item AV-27F476/R AV-27F476/S AV-32F476/Y AV-32F476/Z

PICTURE TUBE (ITC) A68ELH021X201 A68QCP693X003 A80AKS90X03 A80ERF182X17

MAIN PWB SGJ-1580A-M2 SGJ-1579A-M2 SGJ-1572A-M2 SGJ-1575A-M2

CRT SOCKET PWB SGJ-3523A-M2 ← SGJ-3521A-M2 SGJ-3522A-M2

2.3 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-27F476

AC 120V 60Hz

MODEL NO.

TV SCREEN SIZE : DIAGONAL

CHASSIS NO.
MANUFACTURED
SERIAL NO.

W

INCHES

ME

VIDEO EQUIPMENT

4C43

AV-32F476

DISTINGUISH NAME

RA

SA

YA

ZA

1-4 (No.YA243)

2.4 TECHNICAL INFORMATION

2.4.1 MAIN MI-COM (CPU) PIN FUNCTION

Pin

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 [Reset: L] 33 BLACK_DET - Black level detection filter

6 8MHz_OUT O CPU system clock: 8MHz oscillation 34 SVM_OUT O Y signal for scan 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 I 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 I 5V (for video process circuit)

11 uP_VVSS - GND 39 R_OUT O R signal for CRT output

12 TV_HGND - GND 40 G_OUT O G signal for CRT output

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

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

15 H_Vcc I 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: Aspect size control [PANORAMA: L]

21 Ys I Not used 49 SDA0 I/O Data for Inter IC control bus (for various devices)

22 Cb_IN I Cb (external) signal 50 SCL0 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 I 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

Pin name I/O Function

No.

MONITOR_OUT

O Not used

(No.YA243)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 4 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], then remove the SPEAKER with

SPEAKER HOLDER.

(2) Remove the 2 screws [D], then remove the SPEAKER

from the SPEAKER HOLDER.

(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.YA243)

FRONT CABINET

LED & POWER SW PWB

D

C

SPEAKER

CRT SOCKET PWB

SPEAKER HOLDER

FRONT CONTROL PWB

MAIN PWB

Claw

F

E

REAR COVER

Claw

AV SELECTOR PWB

POWER CORD

AV TERMINAL
BOARD

B

Fig.1

A

(No.YA243)1-7

3.1.9 REMOVING THE CRT

NOTE:

• Replacement of the CRT should be performed by 2 or more

persons.

• After removing the REAR COVER, CHASSIS etc.,
(1) Putting the CRT change table on soft cloth, the CRT

change table should also be covered with such soft cloth
(shown in Fig. 2).

(2) While keeping the surface of CRT down, mount the TV set

on the CRT change table balanced will as shown in Fig. 2.

(3) Remove 4 screws marked by arrows with a box type screw-

driver as shown in Fig. 3.

NOTE:

Since the cabinet will drop when screws have been
removed, be sure to support the cabinet with hands.

(4) After 4 screws have been removed, put the cabinet slowly

on cloth (At this time, be carefully so as not to damage the
front
surface of the cabinet) shown in Fig. 4.

NOTE:

• The CRT should be assembled according to the
opposite sequence of its dismounting steps.

• The CRT change table should preferably be smaller
that the CRT surface, and its height be about 35cm.

CRT CHANGE TABLE

CLOTH

CRT
CHANGE
TABLE

Fig.2

CRT

Fig.3

APPROX.
35cm

BOX
TYPE
SCREW
DRIVER

CRT

CABINET

CRT
CHANGE TABLE

Fig.4

COATING OF SILICON GREASE FOR ELECTRICAL INSULATION ON THE CRT ANODE CAP SECTION.

Subsequent to replacement of the CRT and HV transformer or repair of the anode cap, etc. by dismounting them, be sure to coat
silicon grease for electrical insulation as shown in Fig.5.Wipe around the anode button with clean and dry cloth. (Fig.5)Coat silicon
grease on the section around the anode button. At this time, take care so that any silicon greases dose not sticks to the anode
button. (Fig.6)

Silicon grease product No. KS - 650N

CRT

Anode button

Approx.
20mm (Do not
coat grease on
this section

Silicon grease
should be coated
by 5mm or more
from the outside
diameter of anode
cap.

1-8 (No.YA243)

Silicon grease

coating

Fig.5

Anode button
(No sticking of
silicon grease)

Fig.6

Coating position
of silicon grease

Anode cap

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 plug.

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

SERV ICE MENU

1.

V/C(S)

3.

SOUND(A)

5.

3L Y/C(LYC)

7.

LOW LIGHT

9.

VCO

11.

I2C BUS

SELECT BY
OPERATE BY

2.

DEF(D)

4.

OTHERS(F)

8.

HIGH LIGHT

12.

SYSTEM(SYS)

EXIT BY

Fig.1

Setting items Settings Item No.

1. V/C(S)

(Video setting)

2. DEF(D)

(Deflection setting)

3. SOUND(A)
(Audio setting)

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

5. 3L Y/C(LYC) [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]

2

C BUS setting)

(I

12.SYSTEM (SYS)

(System constant setting)

Adjust S01~S48

Adjust D01~D33

Adjust A01~A08

Fixed F01~F18

Fixed LYC01~LYC12

Adjust ---

Adjust ---

Adjust ---

Fixed ---

Fixed SYS01~SYS26

EXIT

(No.YA243)1-9