JVC AV-N21204/SA Service Manual

52128200304

POWER

DISPLAY

INPUT

100+

RETURN+

MUTING

MENU

CHIP

EXIT

CHANNEL

VCR CONTROL

POWER

TV/VCR

REC

STOP

PAUSE

PLAYFFFF

REW

SLEEP
TIMER

VIDEO

STATUS

RM-C205

AV-N21204

SERVICE MANUAL

COLOR TELEVISION

BASIC CHASSIS

AV-N21204/SA

FV5

SLEEP

VIDEO

POWER

TIMER

STATUS

DISPLAY

INPUT

1

3

2

4

6

5

7

9

8

100+

RETURN+

0

MUTING

V—CHIP

+

CH

VOL

VOL

+

CH

MENU

EXIT

VCR CONTROL

CHANNEL

POWER

TV/VCR

PLAY

REW

PAUSE

REC

STOP

RM-C205

TABLE OF CONTENTS

1 PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

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

3 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11

4 TROUBLE SHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29

COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LTD.

No.52128

2003/04

AV-N21204

SPECIFICATION

Items Contents

Dimensions (W x H x D) 59.2cm x 45.6cm x 48.7cm (23-3/8” x 18” x 19-1/4”)

Mass 20.4 kg (45.0 Ibs)

TV RF System CCIR (M)

Color Sound System NTSC, BTSC system (Multi Channel Sound)

TV Receiving Channels and Frequency

VHF LOW

VHF HIGH

TV/CATV Total Channel 180 channels

Intermediate Frequency

Video IF Carrier

Sound IF Carrier

Color Sub Carrier 3.58MHz

Power Input AC 120V, 60Hz

Power Consumption 87W

Picture Tube 21” (51cm) measured diagonally H : 40.6cm x V : 30.5cm

High Voltage 26.5kV±1kV (at zero beam current)

Speaker 5 x 9cm (2” x 3-1/2”) Oval type x 2

Audio Power Output 1W+1W

Antenna terminal (VHF/UHF) F-type connector, 75ohm

Video / Audio Input (1 / 2 / 3)

Video (1 / 3)

Audio (1 / 2 / 3)

S-Video (1)

Component video (2)

Audio Output (Variable) More then 0~1550mV(rms) (+6dBs)

Headphone Jack 3.5mm mini jack x 1

Remote Control Unit RM-C205 (AA/R6/UM-3 battery x 2)

02ch~06ch : 54MHz~88MHz
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~1 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

45.75MHz

41.25MHz (4.5MHz)

1V(p-p), 75ohm (RCA pin jack x 2)
500mV(rms) (-4dBs), high Impedance (RCA pin jack x 8)
Mini DIN 4pin x 1
Y : 1V(p-p) positive (negative sync provided, when terminated with 75ohm)
C : 0.286V(p-p) (burst signal when terminated with 75ohm)
RCA pin jack x 3
Y : 1V(p-p) positive (negative sync provided, when terminated with 75ohm)
Pb/Pr : 0.7V(p-p) 75ohm

low impedance (400Hz when modulated 100%) (RCA pin jack x 2)

Design & specifications are subject to change without notice.

1-2 (No.52128)

SECTION 1

PRECAUTIONS

AV-N21204

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 that 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

(NEUTRAL) 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 with a measuring
apparatus (oscilloscope etc.) the LIVE side GND and
ISOLATED(NEUTRAL) side GND or EARTH side GND at the same
time.
If above note will not be kept, a fuse or any parts will be broken.

(6) 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.

(7) 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).

(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, screwheads, 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

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 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
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 1500ohm 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

GOOD EARTH GROUND

1500 10W

ON EACH EXPOSED
ME TAL PART

(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”.

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

POWER CORD
REPLACEMENT WARNING.

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

PWB

White line side

A V

WHT

PW

“Leakage

(No.52128)1-3

AV-N21204

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

2.1 FEATURES

• New chassis design enables use of a single board with simplified circuitry.

• 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 IC.

• Adoption of the VIDEO STATUS function.

• Adoption of the ON/OFF TIMER function.

• With 75ohm V/U in common (F-Type) ANT Terminal.

• SLEEP TIMER for setting in real time.

• Closed-caption broadcasts can be viewed.

• Audio Video input terminal.

• Variable Audio output terminal.

• Built-in MTS system.

2.2 SYSTEM BLOCK DIAGRAM

TUNER

TUNER

CONTROL

MEMORY IC

SCL

CPU

(MAIN MICON)

SCL

MTS/TONE

SDA

SDA

AFC

DECODER

IF

1 Chip

REMOTE

CONTROL

1-4 (No.52128)

2.3 DISASSEMBLY PROCEDURE

AV-N21204

2.3.1 REMOVING THE REAR COVER

(1) Unplug the power plug.
(2) As shown in the Fig.1, remove the 9 screws [A].
(3) As shown in Fig.1, remove the 2 screws [B].
(4) Then remove the REAR COVER toward you.

2.3.2 REMOVING THE MAIN PWB

• Remove the REAR COVER.
(1) Raise the backside of the MAIN PWB, and remove the

PWB STOPPER [C] from the cabinet.

(2) Withdraw the MAIN PWB backward. (If necessary, remove

the wire clamp, connectors etc.)

2.3.3 REMOVING THE SPEAKER

• Remove the REAR COVER.
(1) As shown in Fig.1, remove the 4 screws [D], then remove

the SPEAKER.

(2) Follow the same steps when remove the other hand

SPEAKER.

NOTE:

When removing the 4 screws [D] of the SPEAKER, remove the
lower side screw first, and then remove the upper one.

2.3.4 CHECKING THE PW BOARD

• Remove the REAR COVER.
(1) Pull out the MAIN CHASSIS (refer to REMOVING THE

MAIN PWB).

(2) Erect the MAIN CHASSIS vertically so that you can easily

check the backside of the PW Board.

2.3.5 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
onnected to the CRT SOCKET PW board.

2.3.6 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.

(No.52128)1-5

AV-N21204

FRONT CABINET

SPEAKER

D

CRT SOCKET PWB

MAIN PWB

HVT

SPEAKER

REAR COVER

D

TUNER

C

PWB STOPPER

1-6 (No.52128)

B

A

POWER CORD

Fig.1

2.4 REPLACEMENT OF MEMORY IC

2.4.1 MEMORY IC

This TV use memory IC.
In the memory IC, there are memorized data for correctly operating the video and deflection circuits.
When replacing the memory IC, be sure to use IC written with the initial values of data.

2.4.2 PROCEDURE FOR REPLACING MEMORY IC

(1) Power off

Switch the power off and unplug the power plug.

(2) Replace IC

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

(3) Power on

Connect the power plug and switch the power on.

(4) Setting of receive channels

Set the receive channels. For setting, refer to the OPERATING INSTRUCTIONS.

(5) User settings

Check the user setting items according to TABLE “USER SETTING VALUE”, and if these are different, set the correct value.

(6) CHECK THE SYSTEM CONSTANT ITEMS

If the value of each item of a system setup is not correctly set
as a value peculiar to this television, operation of a
microcomputer and the output of an image do not become
suitable. Please set up the value of each item correctly,
according to the following description.

(1) Press the [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 (Fig.1).
(2) The SERVICE MENU screen of Fig.1 will be displayed.
(3) While the SERVICE MENU is displayed, again

simultaneously press the [DISPLAY] and [VIDEO

STATUS] keys to display the SYSTEM CONSTANT

screen (Fig.2).
(4) Refer to the Table 1 of SYSTEM CONSTANT SETTING,

and check the setting items. Where these differ, select

the item with the [CH (-/+)] key and adjust it with the [VOL

(-/+)] keys (The letters of the selected item are displayed

in yellow).
(5) The setting value will be stored automatically when

release the remote control unit keys.
(6) Press the [EXIT] key twice to return to the normal screen.

SERVICE MENU

PICTURE SOUND
GAME
LOW LIGHT HIGH LIGHT
RF AFC CHK
VCO(CW)

SELECT BY EXIT BY
OPERATE BY

EXIT

Fig.1

SYSTEM CONSTANT

MODEL
V-CHIP
CAN V-CHIP

******** *****

SELECT BY EXIT BY
OPERATE BY

:
:
:

*******

NO
NO

EXIT

Fig.2

(7) SERVICE MENU setting

Verify what to set in the SERVICE MENU, and set whatever is necessary. Refer to the SECTION 3 ADJUSTMENT for setting.

AV-N21204

(No.52128)1-7

AV-N21204

2.4.3 SYSTEM CONSTANT SETTING

Setting item

MODEL

V-CHIP

CAN V-CHIP

ޓAV-27220

ޓC-13210

Setting content

AV-20220

C-20210

YES NO

YES NO

2.4.4 USER SETTING VALUE

Setting item Setting value

1. Use remote controller keys

POWER Off

CHANNEL CH 02

CHANNEL PRESET See OPERATING INSTRUCTIONS.

VOLUME 10

INPUT (TV/VIDEO) TV

DISPLAY Off

SLEEP TIMER 0

VIDEO STATUS STANDARD

2. Setting of MENU

TINT Center

COLOR Center

PICTURE Center

BRIGHT Center

DETAIL Center

BASS Center

TREBLE Center

BALANCE Center

MTS STEREO

TV SPEAKER ON

NOISE MUTING ON

SET VIDEO STATUS All center

SET CLOCK Unnecessary to set

ON/OFF TIMER Off

LANGUAGE ESP

CLOSED CAPTION Off

BACKGROUND BLACK

AUTO TUNER SETUP TUNER MODE : AIR

CHANNEL SUMMARY Unnecessary to set

SET LOCK CODE Unnecessary to set

Initial setting value

AV-20220

NO

NO

1-8 (No.52128)

2.4.5 SERVICE MENU SETTING ITEM

Menu item Setting item Menu item Setting item

PICTURE 1. BRIGHT GAME TINT

2. PICTURE COLOR

3. TV DETAIL PICTURE

4. TV BPF BRIGHT

5. TINT DETAIL

6. COLOR LOW LIGHT RED

7. EXT BRIGHT GREEN

8. EXT PICTURE BLUE

9. EXT DETAIL HIGH LIGHT GREEN

10. EXT BPF BLUE

11. EXT TINT RF AFC CHECK

12. EXT COLOR FINE

13. V SIZE STATUS

14. V CENTER VCO(CW) Refer to “ADJUSTMENTS PROCEDURE”

15. H POSITION

16. OSD H POSITION

17. OSD V POSITION

18. H AFC

19. RF AGC

20. OSD SELECT

SOUND 1. IN LEVEL

2. FH MON

3. ST VCO

4. PILOT

5. FILTER

6. LOW SEP

7. HIGH SEP

8. 5FH MON

9. SAP VCO

10. FIL OFF

[Do not adjust]

RF AFC

AV-N21204

(No.52128)1-9