JVC AV-20D304/SA User manual

SERVICE MANUAL
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LTD. No.52103
2003/02
AV-20D304
COLOR TELEVISION
52103200302
AV-20D304/SA
TABLE OF CONTENTS
1 PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
3 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
BASIC CHASSIS
FE2

AV-20D304
1-2 (No.52103)
SPECIFICATION
Design & specifications are subject to change without notice.
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 20.4kg (45 Ibs)
TV RF System CCIR(M)
Color Sound System NTSC, BTSC system (Multi Channel Sound)
TV Receiving Channels and Frequency
VL Band
VH Band
UHF Band
02ch~06ch : 54MHz~88MHz
07ch~13ch : 174MHz~216MHz
14ch~69ch : 470MHz~806MHz
CATV Receiving Channels and Frequency
Low Band
High Band
Mid Band
Super Band
Hyper Band
Ultra Band
Sub Mid Band
54MHz~804MHz
02~06, A-8 by 02~06&01
07~13 by 07~13
A~1 by 14~22
J~W by 23~36
W+1~W+28 by 37~64
W+29~W+84 by 65~125
A8, A4~A1 by 01, 96~99
TV/CATV Total Channel 180 channels
Intermediate Frequency
Video IF Carrier
Sound IF Carrier
45.75MHz
41.25MHz (4.5MHz)
Color Sub Carrier 3.58MHz
Power Input 120V AC, 60Hz
Power Consumption 75W
Picture Tube 20” (51cm) measured diagonally H : 40.6cm x V : 30.5cm
High Voltage 26.3kV±0.5kV (at zero beam current)
Speaker 5 x 9cm (2” x 3-1/2”) Oval type x 2
Audio Power Output 1.2W x 2
Antenna terminal (VHF/UHF) F-type connector, 75ohm
Video / Audio Input (1 / 2 / 3)
Video (1 / 3)
Audio (1 / 2 / 3)
S-Video (Input 1)
Component (Input 2)
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
Audio Output (Variable) More then 0~1550mV(rms) (+6dBs)
low impedance (400Hz when modulated 100%) (RCA pin jack x )
Headphone Jack 3.5mm mini jack x 1
Remote Control Unit RM-C1254G (AA battery x 2)

AV-20D304
(No.52103)1-3
SECTION 1
PRECAUTIONS
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
10kΩ2W 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 "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 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.).
(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".
AC VOLTMETER
(HAVING 1000 /V,
OR MORE SENSITIVITY)
PLACE THIS PROBE
ON EACH EXPOSED
METAL PART
1500 10W
0.15 F AC-TYPE
GOOD EARTH GROUND
PWB
White line side
WHT
PW
POWER CORD
REPLACEMENT WARNING.
Connecting the white line side of power
cord to "WHT" character side.
A V
This mark shows a fast
operating fuse, the
letters indicated below
show the rating.

AV-20D304
1-4 (No.52103)
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
2.1 FUNCTIONS
[REAR PANEL] [REMOTE CONTROL UNIT]
(RM-C1254G)
[FRONT PANEL]
MENU POWERCHANNEL VOLUME

AV-20D304
(No.52103)1-5
2.2 DISASSEMBLY PROCEDURE
2.2.1 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 4 screws [B].
(4) Then remove the REAR COVER toward you.
2.2.2 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.)
2.2.3 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.
2.2.4 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.
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.
2.2.5 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.

AV-20D304
1-6 (No.52103)
Fig.1
PWB STOPPER
D
C
D
SPEAKER
SPEAKER
MAIN PWB
CRT SOCKET PWB
REAR COVER
POWER CORD
FEONT CABINET
HVT
A
B

AV-20D304
(No.52103)1-7
2.3 MEMORY IC REPLACEMENT
2.3.1 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.
2.3.2 PROCEDURE FOR REPLACING MEMORY IC
(1) Power off
Switch the power off and unplug the power cord from the outlet.
(2) Replace IC
Be sure to use a memory IC written with the initial setting data.
(3) Power on
Connect the power cord to the outlet 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 “USER SETTING VALUES”, and if these are different, set the correct value.
(6) SERVICE MENU setting
Verify what to set in the SERVICE MENU, and set whatever is necessary. Refer to the ADJUSTMENT for setting.
1.V/C(S)
3.SOUND(A)
7.LOW LIGHT
9.VCO
11.I2C BUS
SERVICE MENU
2.DEF(D)
4.OTHERS(F)
8.HIGH LIGHT
SELECT BY
OPERATE BY EXIT BY EXIT
KEY ASSIGNMENT OF REMOTE CONTROL UNIT
SLEEP
TIMER
DISPLAY
VIDEO
STATUS
VOLUME
- / +
CHANNEL
+ / -
EXIT

AV-20D304
1-8 (No.52103)
2.3.3 USER SETTING VALUES
Setting item Setting value Setting item Setting value
REMOTE CONTROL UNIT KEY
POWER OFF DISPLAY OFF
CHANNEL CH-02 VIDEO STATUS DYNAMIC
VOLUME 15 HYPER SURROUND OFF
TV/VIDEO TV
SETTING OF MENU
PICTURE MODE INITIAL SETUP MODE
TINT Center LANGUAGE ENG
COLOR Center FRONT PANELLOCK OFF
PICTURE +8 V2 COMPONENT-IN NO
BRIGHT Center AUTO SHUT OFF OFF
DETAIL +10 CLOSED CAPTION OFF
NOISE MUTING ON AUTO TUNER SET UP AIR
SOUND MODE CHANNEL SUMMARY Unnecessary to set
BASS Center V-CHIP OFF
TREBLE Center SET LOCK CODE (0000) Unnecessary to set
BALANCE Center XDS ID ON
MTS STEREO
CLOCK / TIMERS MODE
SET CLOCK MANUAL
TIME ZONE PACIFIC
D.S.T. OFF
ON / OFF TIMER OFF

AV-20D304
(No.52103)1-9
2.4 REPLACEMENT OF CHIP COMPONENT
2.4.1 CAUTIONS
(1) Avoid heating for more than 3 seconds.
(2) Do not rub the electrodes and the resist parts of the pattern.
(3) When removing a chip part, melt the solder adequately.
(4) Do not reuse a chip part after removing it.
2.4.2 SOLDERING IRON
(1) Use a high insulation soldering iron with a thin pointed end of it.
(2) A 30w soldering iron is recommended for easily removing parts.
2.4.3 REPLACEMENT STEPS
1. How to remove Chip parts
[Resistors, capacitors, etc.]
(1) As shown in the figure, push the part with tweezers and
alternately melt the solder at each end.
(2) Shift with the tweezers and remove the chip part.
[Transistors, diodes, variable resistors, etc.]
(1) Apply extra solder to each lead.
(2) As shown in the figure, push the part with tweezers and
alternately melt the solder at each lead. Shift and remove
the chip part.
Note :
After removing the part, remove remaining solder from the
pattern.
2. How to install Chip parts
[Resistors, capacitors, etc.]
(1) Apply solder to the pattern as indicated in the figure.
(2) Grasp the chip part with tweezers and place it on the
solder. Then heat and melt the solder at both ends of the
chip part.
[Transistors, diodes, variable resistors, etc.]
(1) Apply solder to the pattern as indicated in the figure.
(2) Grasp the chip part with tweezers and place it on the
solder.
(3) First solder lead Aas indicated in the figure.
(4) Then solder leads Band C.
SOLDER SOLDER
A
B
C
A
B
C

AV-20D304
1-10 (No.52103)
SECTION 3
ADJUSTMENT
3.1 ADJUSTMENT PREPARATION
(1) There are 2 ways of adjusting this TV : One is with the REMOTE CONTROL UNIT and the other is the conventional method
using adjustment parts and components.
(2) The adjustment using the REMOTE CONTROL UNIT is made on the basis of the initial setting values. The setting values which
adjust the screen to the optimum condition can be different from the initial setting values.
(3) Make sure that connection is correctly made AC to AC power source.
(4) Turn on the power of the TV and measuring instruments for warning up for at least 30 minutes before starting adjustments.
(5) If the receive or input signal is not specified, use the most appropriate signal for adjustment.
(6) Never touch the parts (such as variable resistors, transformers and condensers) not shown in the adjustment items of this service
adjustment.
(7) Preparation for adjustment. Unless otherwise specified in the adjustment items, preset the following functions with the REMOTE
CONTROL UNIT.
3.2 MEASURING INSTRUMENT AND FIXTURES
(1) DC voltmeter (or digital voltmeter)
(2) Oscilloscope
(3) Signal generator (Pattern generator : NTSC)
(4) TV audio multiplex signal generator
(5) Remote control unit
Item Preset value
PICTURE MODE (VSM) DYNAMIC
TINT, COLOR, PICTURE, BRIGHT, DETAIL CENTER
MTS STEREO
BASS TREBLE BALANCE CENTER
HYPER SURROUND OFF

AV-20D304
(No.52103)1-11
3.3 ADJUSTMENT LOCATIONS
Fig.1
CRT SOCKET PWB
(Within MAIN PWB ASS'Y)
T
TP-E
(SOLDER SIDE)
TOP
CRT EARTH
(BRAIDED ASS'Y)
E1
TP-B
MAIN PWB
POWER
FRONT
HV
UPPER : FOCUS
LOWER : SCREEN
X
TUNER
MEMORY
IC201
IC702
IC421
HVT
S
AV IN / OUT
VOL+ VOL- CH+ CH- MENU
POWER
B1
IC901
F901
U
IC101
T111
S401

AV-20D304
1-12 (No.52103)
3.4 BASIC OPERATION OF SERVICE MENU
3.4.1 TOOL OF SERVICE MENU OPERATION
Operate the SERVICE MENU with the REMOTE CONTROL UNIT.
3.4.2 SERVICE MENU ITEMS
With the SERVICE MENU, various adjustments can be made, and they are broadly classified in the following items of settings.
(1) V/C (S) This mode adjusts the VIDEO and CHROMA control circuit.
(2) DEF (D) This mode adjusts the DEFLECTION control circuit.
(3) SOUND (A) This mode adjusts the SOUND control circuit.
(4) OTHERS (F) This mode adjusts the display setting and the other settings (Do not change the values).
(7) LOW LIGHT This mode adjusts the WHITE BALANCE (LOW LIGHT) control circuit.
(8) HIGH LIGHT This mode adjusts the WHITE BALANCE (HIGH LIGHT) control circuit.
(9) VCO This mode adjusts the VCO control circuit.
(11) I2C BUS This mode adjusts the I2C BUS control circuit (They are fixed).

AV-20D304
(No.52103)1-13
3.4.3 BASIC OPERATION IN SERVICE MENU
3.4.3.1 HOW TO ENTER THE SERVICE MENU
(1) Press the [SLEEP TIMER] key and set the SLEEP TIMER
for "0 MIN".
Then press the [DISPLAY] key and [VIDEO STATUS] key
of the remote control unit at the same time to enter the
SERVICE MENU screen.
Fig.1
3.4.3.2 SUB MENU SCREEN SELECTION
Press [VOLUME (-/+)] keys of the remote control unit, and select
the SUB MENU SCREEN from SERVICE MENU.
In SERVICE MENU, press the [CHANNEL (-/+)] key to select any
of the SUB MENU items. The letters of the selected items are
displayed in yellow.
Fig.2
3.4.3.3 SETTING METHOD
[1.V/C(S) ADJUSTMENT MODE]
For example, adjust the 1.V/C(S) by using the remote control unit.
1) Press the [CHANNEL (-/+)] keys to select the one of adjustment mode from S01 BRIGHT to S21 AGC ADJ.
2) Press the [VOLUME (-/+)] keys to change the adjustment value. The setting value will be stored automatically when release
the REMOTE CONTROL UNIT keys.
It can adjust the items from 1.V/C(S) to 3.SOUND(A) in the same procedure.
[7.LOW LIGHT, 8.HIGH LIGHT AND 9.VCO ADJUSTMENT MODE]
Since the key operation in this mode is peculiar, please refer to the clause of the "ADJUSTMENT PROCEDURE".
[4.OTHERS AND 11.I2C BUS ADJUSTMENT MODE]
These are no requirement for adjustment. Setting only. Don't change these values.
3.4.3.4 RELEASE OF SERVICE MENU
When adjustment is completed, press the [EXIT] key twice. Then return to the normal screen.
1.V/C(S)
3.SOUND(A)
7.LOW LIGHT
9.VCO
11.I2C BUS
SERVICE MENU
2.DEF(D)
4.OTHERS(F)
8.HIGH LIGHT
SELECT BY
OPERATE BY EXIT BY EX IT
1.V/C(S) 2.DEF(D)
3.SOUND(A) 4.OTHERS(F)
7.LOW LIGHT 8.HIGH LIGHT
9.VCO
11.I2C BUS
KEY ASSIGNMENT OF REMOTE CONTROL UNIT
SLEEP
TIMER
DISPLAY
VIDEO
STATUS
VOLUME
- / +
CHANNEL
+ / -
EXIT

AV-20D304
1-14 (No.52103)
3.4.4 SERVICE MENU FLOW CHART
Fig.3
1.V/C(S)
RF 4 : 3 STD LOW
S01 BRIGHT
RF 4 : 3 STD LOW
D01 V FREQ
BRIGHT
2.DEF(D)
7.LOW LIGHT
8.HIGH LIGHT
3.SOUND(A)
4.OTHERS(F)
9.VCO
11.I2C BUS
SERVICE MENU
1.V/C(S) 2.DEF(D)
3.SOUND(A) 4.OTHERS(F)
7.LOW LIGHT 8.HIGH LIGHT
9.VCO
11.12C BUS
SELECT BY
OPERATE BY EXIT BY
TOO HIGH GOOD TOO LOW
SYNC: YES
AFC ON
FINE 0
I2C BUS ON
F01 OSD POSI
A01 IN LEVEL
***
SERVICE MENU (MAIN MENU)
EXIT
***
***
***
******
***
***
Do not adjust
Do not adjust

AV-20D304
(No.52103)1-15
3.5 INITIAL SETTING VALUE OF SERVICE MENU
(1) Adjustment of the SERVICE MENU is made on the basis of the initial setting values. However, the new setting values which
displays on the screen in its optimum condition may differ from the initial setting value.
(2) Do not change the initial setting values of the items not listed in "ADJUSTMENT PROCEDURE".
(3) "---" is impossible to adjust.
3.5.1 [1.V / C]
No. Setting item Variable range
Initial setting value
RF EXTERNAL (SV / CV) COMPONENT
STANDARD THEATER STANDARD THEATER STANDARD THEATER
S01 BRIGHT 0~127 64 --- --- --- --- ---
S02 PICTURE 0~127 65 --- --- --- --- ---
S03 COLOR 0~127 41 --- --- --- 47 ---
S04 TINT 0~127 63 --- --- --- 64 ---
S05 DETAIL 0~63 30 --- 35 --- 40 ---
S06 BRIGHT +- -128~+127 --- 0 1 --- 1 ---
S07 PICT+- -128~+127 --- -15 0 --- 0 ---
S08 COLOR +- -128~+127 --- -3 0 --- --- ---
S09 TINT+- -128~+127 --- -6 -4 --- --- ---
S10 DETAIL+- -128~+127 --- 3 --- --- --- ---
No. Setting item Variable range
Initial setting value
RF/EXT (SV / CV) COMPONENT
STANDARD THEATER STANDARD THEATER
LOW HIGH LOW HIGH LOW HIGH LOW HIGH
S11 R CUT OFF 0~255 30 --- --- --- --- --- --- ---
S12 G CUT OFF 0~255 30 --- --- --- --- --- --- ---
S13 B CUT OFF 0~255 30 --- --- --- --- --- --- ---
S14 R DRIVE 0~127 64 --- --- --- --- --- --- ---
S15 B DRIVE 0~127 64 --- --- --- --- --- --- ---
S16 R CUT+- -128~+127 --- 0 0 0 0 --- --- ---
S17 G CUT+- -128~+127 --- 0 0 0 0 --- --- ---
S18 B CUT+- -128~+127 --- 0 0 0 0 --- --- ---
S19 R DRV+- -128~+127 --- 5 13 7 0 --- --- ---
S20 B DRV+- -128~+127 --- 6 -25 -9 0 --- --- ---
No. Setting item Variable range Initial setting value
S21 AGC ADJUST 0~127 64

AV-20D304
1-16 (No.52103)
3.5.2 [2.DEF]
3.5.3 [3.SOUND MODE]
3.5.4 [4.OTHERS]
3.5.5 [7.LOW LIGHT MODE]
3.5.6 [8.HIGH LIGHT MODE]
No. Setting item Variable range Initial setting value
RF EXTERNAL (SV / CV)
D01 AFC GAIN 0~3 0 2
D02 H POSI 0~31 13 13
D03 V SIZE 0~125 65 65
D04 V S CORR 0~15 0 0
D05 V LIN 0~15 8 8
D06 H SIZE 0~63 32 32
D07 WVMT TOP 0~3 0 0
D08 WVMT BTM 0~3 0 0
D09 EWCR TOP 0~31 16 16
D10 EWCR BTM 0~31 16 16
D11 EW PARA 0~63 26 26
D12 BLANK SW 0~1 0 0
No. Setting item Variable range Initial setting value
A01 IN LEVEL 0~63 36
A02 FH MON 0~1 0
A03 ST VCO 0~63 43
A04 PIL CAN 0~1 0
A05 FILTER 0~63 35
A06 LOW SEP 0~63 8
A07 HI SEP 0~63 26
A08 5FH MON 0~1 0
A09 SAP VCO 0~63 44
No. Setting item Variable range Initial setting value
F01 OSD POSI 0~255 28
F02 OSD PREQ 0~255 85
F03 CCD POSI 0~63 47
F04 CCD FREQ 0~255 94
F05 CCD CONT 0~63 11
F06 PUR CONT 0~255 62
F07 VNR CHK 0~255 3
F08 VCSN TM 0~255 5
F09 CCD PCHK 0~1 1
No. Setting item Variable range Initial setting value
1 RED 0~255 30
2 GREEN 0~255 30
3 BLUE 0~255 30
No. Setting item Variable range Initial setting value
1 RED 0~255 64
2 BLUE 0~255 64

AV-20D304
(No.52103)1-17
3.6 ADJUSTMENTS PROCEDURE
3.6.1 CHECK ITEM
3.6.2 VCO
3.6.3 RF AGC
Item Measuring
instrument Test point Adjustment part Description
B1 POWER
SUPPLY
DC voltmeter
Signal
generator
B1 Connector
TP-91
TP-E
[MAIN PWB]
(1) Receive the black and white signal. (color off)
(2) Connect the DC voltmeter to TP-91 (B1 connector 1
pin) and TP-E (B1 connector 3 pin).
(3) Confirm that the voltage is DC134V±2V.
Item Measuring
instrument Test point Adjustment part Description
IF VCO Remote
control unit
[9.VCO]
CW transf. (T111)
[MAIN PWB]
• It must not adjust without inputting the RF signal.
(1) Receive a broadcast.
(2) Select 9.VCO in the SERVICE MENU.
(3) Confirm that the color change from "TOO HIGH" to
"TOO LOW" by CW transf. on MAIN PWB, and
check the "SYNC : YES".
(4) Adjust CW transf. until "GOOD" letters turns green.
And then confirm that the "SYNC : YES" again.
Adjustment can be done in this statement.
(5) Push the [EXIT] key to exit the [9.VCO] mode.
TOO HIGH GOOD TOO LOW
SYNC: YES
AFC ON
FINE 0
Item Measuring
instrument Test point Adjustment part Description
RF AGC Signal
generator
Remote
control unit
[1.V/C(S)]
S21 : AGC ADJ
(1) Receive a black and white signal (colour off).
(2) Select <S21>(AGC ADJ) of the 1.V/C(S).
(3) Press the [MUTING] key and turn the picture color
off.
(4) With the [VOLUME (-)] key to get the noise in the
screen picture (zero side of setting value).
(5) Press the [VOLUME (+)] key several times and step
when noise disappears from the screen (at that time,
not to increase the value too much).
(6) Change to other channels and make sure that there
is no irregularity.
(7) Press the [MUTING] key and get color out.
No
S21
Setting item
AGC ADJ 0~127
Variable
range
Initial setting
value
80

AV-20D304
1-18 (No.52103)
3.6.4 FOCUS
3.6.5 DEFLECTION CIRCUIT
Item Measuring
instrument Test point Adjustment part Description
FOCUS Signal
generator
FOCUS VR
[In HVT]
(1) Receive the crosshatch signal.
(2) While looking at the screen, adjust the FOCUS VR
to the vertical and horizontal lines will be clear and in
fine detail.
(3) Make sure that the picture is in focus even when the
screen gets darkened.
Item Measuring
instrument Test point Adjustment part Description
V. SIZE &
V. CENTER
Signal
generator
Remote
control unit
[2.DEF(D)]
D03 : V SIZE
V. CENTER SW(S401)
[MAIN PWB]
(1) Receive the crosshatch signal.
(2) Select the <D03>(V SIZE).
(3) Adjust the <D03> so that the vertical screen size
becomes 90%.
(4) Adjust the V’ CENTER SW to agree the vertical cen-
ter with display center.
H. CENTER Signal
generator
Remote
control unit
[2.DEF(D)]
D02 : H POSI
(1) Receive the crosshatch signal.
(2) Select <D02>(H POSI).
(3) Adjust the <D02> so that left width and right width of
the crosshatch screen becomes equal.
Picture
size
(100%)
Screen
size
(90%)
No
S03
Setting item
V SIZE 0~125
Variable
range
Initial setting
value
65
No
D02
Setting item
H POSI 0~31
Variable
range
Initial setting
value
10

AV-20D304
(No.52103)1-19
3.6.6 VIDEO CIRCUIT
Item Measuring
instrument Test point Adjustment part Description
WHITE
BALANCE
(LOW LIGHT)
Signal
generator
Remote
control unit
[7.LOW LIGHT]
[1.V/C(S)]
S11 : R CUTOFF
S12 : G CUTOFF
S13 : B CUTOFF
S01 : BRIGHT
SCREEN VR
[ in HVT]
(1) Receive the black and white signal ( color off ).
(2) Select the 7.LOW LIGHT in the SERVICE MENU.
(3) Set the initial setting value of <S11>(R CUTOFF),
<S12>(G CUTOFF), <S13>(B CUTOFF) and
<S01>(BRIGHT).
(4) Display a single horizontal line by pressing the [1]
key.
(5) Turn the SCREEN VR all the way to the left.
(6) Turn the SCREEN VR gradually to the right from the
left until either one of the red, blue or green color
appears faintly.
(7) Adjust the two colors which did not appear until the
single horizontal line that is displayed becomes
white using the [4] to [9] keys.
(8) Turn the SCREEN VR until the single horizontal line
is displayed faintly.
(9) Press the [2] key to cancel the single horizontal line
mode.
(10) Adjust the <S01> level to become the black
component shines white slightly by [VOLUME] key.
(11) Confirm that whether the color ingredient of R,G,or B
is visible to the black component, which shines white
slightly.
(12) When the color ingredient can be seen, two colors
other than a visible color is adjusted, and it is made
to look white.
(13) Return the value of <S01> to initial setting value.
NOTE:
If the [3] key is pressed, it can escape from WHITE
BALANCE adjustment mode.
KEY ASSIGNMENT OF REMOTE CONTROL UNIT
R CUTOFF
R CUTOFF
H LINE OFF
H LINE ON
EXIT
G CUTOFF
G CUTOFF
B CUTOFF
B CUTOFF
No
S11
Setting item
R CUT OFF 0~255
Variable
range Initial setting value
30
S12 G CUT OFF 0~255 30
S13 B CUT OFF 0~255 30
S01 BRIGHT 0~127 64