JVC AV-20RM4SE User manual

SERVICE MANUAL
COPYRIGHT © 2005 Victor Company of Japan, Limited No.YA080
2005/2
COLOUR TELEVISION
YA08020052
AV-20RM4SE,
AV-21RM4SE,
AV-21RM4SN,
AV-21RM4SP
TABLE OF CONTENTS
1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19
RM-C1100TV
[AV-21RM4]

1-2 (No.YA080)
SPECIFICATION
Design & specifications are subject to change without notice.
Item Content
AV-20RM4SE AV-21RM4SE AV-21RM4SP AV-21RM4SN
Dimensions ( W ×H ×D )
60.6cm × 47.5cm × 49.0cm 60.6cm ×47.5cm ×47.0cm
Mass 18kg 21kg
TV RF System B/G, L B/G, D/K B/G
Colour Sys-
tem
TV Mode PAL / SECAM PAL
Video Mode PAL / SECAM / NTSC 3.58 / NTSC 4.43
PAL / NTSC 3.58 / NTSC 4.43
Sound System A2 / NICAM
Teletext System TOP / WST
Receiving
Frequency
VHF(VL)
VHF(VH)
UHF
CATV
46.25MHz - 168.25MHz
175.25MHz - 463.25MHz
471.25MHz - 863.25MHz
S01 - S41 / S75 - S79 (B/G), S01 - S20 / S75 - S77(L)
Intermediate
Frequency
VIF
SIF
38.9MHz
33.4MHz (5.5MHz:B/G)
32.4MHz (6.5MHz:L)
Colour Sub
Carrier
Frequency
PAL
SECAM
NTSC
4.43MHz
4.40625MHz / 4.25MHz
3.58MHz / 4.43MHz
Power Input AC220V - AC240V, 50Hz
Power Consumption
85W (Max) / 4W (Standby) 85W (Max) / 3W (Standby)
Aerial Input Terminal 75Ωunbalanced, coaxial
Picture Tube Size Visible size : 48cm (20"),
Measured diagonally
(H:41.2cm ×V:31.2cm)
Visible size : 51cm (21"), Measured diagonally
(H:41.6cm ×V:31.5cm)
High Voltage
26kV (in cut-off service mode) 28kV (in cut-off service mode)
Speaker 5.7cm ×12.6cm, Oval type ×2
Audio Output 5.5W (10%THD)
EXT-1 Input / Output 21-pin Euro connector (SCRAT socket) ×1
EXT-2 Input Video
Audio(L/R)
1V(p-p) 75Ω, RCA pin jack ×1
500mV(rms) (-4dBs), High Impedance, RCA pin jack ×2
Headphone Jack Mono mini jack 3.5mm ×1
Remote Control Unit VE-30017763 (RM-C1100), (AA/R06 dry battery ×2)

(No.YA080)1-3
SECTION 1
PRECAUTION
1.1 SAFETY PRECAUTIONS [EXCEPT FOR UK]
(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) 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 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.
(5) 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).
(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) 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.
(8) 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.
(9) 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 3000V 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.
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 1000Ωper 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)
PLACE THIS PROBE
ON EACH EXPOSED
METAL PART
1500 10W
0.15 F AC-TYPE
GOOD EARTH GROUND

1-4 (No.YA080)
1.2 SAFETY PRECAUTIONS [FOR UK]
(1) The design of this product contains special hardware and 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 product 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 product have special safety-related characteristics. These characteristics are often
not evident from visual inspection nor can the protection afforded by them necessary 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 the 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) The leads in the products are routed and dressed with ties, clamps, tubing’s, barriers and the like to be separated from live parts,
high temperature parts, moving parts and / or sharp edges for the prevention of electric shock and fire hazard. When service is
required, the original lead routing and dress should be observed, and it should be confirmed that they have been returned to
normal, after re-assembling.
WARNING
(1) The equipment has been designed and manufactured to meet international safety standards.
(2) It is the legal responsibility of the repairer to ensure that these safety standards are maintained.
(3) Repairs must be made in accordance with the relevant safety standards.
(4) It is essential that safety critical components are replaced by approved parts.
(5) If mains voltage selector is provided, check setting for local voltage.

(No.YA080)1-5
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
2.1 FEATURES
• It is a remote controlled color television.
• It can tune cable channels.
• Controlling the TV is very easy by its menu driven system.
• It has 1 Euroconnector sockets for external device.
• Front AV Input available.
• Simple teletext (Toptext, WST) system.
• It is possible to connect headphone.
• Direct channel access.
• APS (Automatic Programming System).
• All programs can be named.
• Forward or backward automatic tuning.
• Sleep timer.
• Child Lock.
• Automatic sound mute when no transmission.
• 5 minutes after the broadcasting (closedown), the TV switches
itself automatically to stand-by mode.
2.2 MAIN DIFFERENCE LIST
2.3 21-PIN EURO CONNECTOR (SCART) : EXT-1
(P-P= Peak to Peak, B-W= Blanking to white peak)
Item AV-20RM4SE AV-21RM4SE AV-21RM4SN AV-21RM4SP
MAIN PWB ASSY VE-20161051 VE-20161048 VE-20161045 VE-20161041
TV RF System B/G,D/K ←B/G B/G, L
Colour System (TV mode) PAL, SECAM ←PAL PAL, SECAM
TV RF System B/G,D/K ←B/G B/G, L
Pin No. Signal designation Matching value EXT-1
1 AUDIO R output 500mV(rms) (Nominal), Low impedance Used (TV OUT)
2 AUDIO R input 500mV(rms) (Nominal), High impedance Used (R1)
3 AUDIO L output 500mV(rms) (Nominal), Low impedance Used (TV OUT)
4 AUDIO GND --- Used
5 GND (B) --- Used
6 AUDIO L input 500mV(rms) (Nominal), High impedance Used (L1)
7 B input 700mV(B-W), 75 ΩUsed
8 FUNCTION SW (SLOW SW) Low : 0V-3V
High : 8V-12V, High impedance
Used
9 GND (G) --- Used
10 SCL / T-V LINK --- Not used
11 G input 700mV(B-W), 75 ΩUsed
12 SDA3 --- Not used
13 GND (R) --- Used
14 GND (YS) --- Used
15 R / C input R : 700mV(B-W), 75 Ω
C : 300mV(P-P), 75 ΩUsed (R)
16 Ys input (FAST SW) Low : 0V-0.4V, 75 Ω
High : 1V-3V, 75 ΩUsed
17 GND (VIDEO output) --- Used
18 GND (VIDEO input) --- Used
19 VIDEO output 1V(P-P) (Negative sync),75 ΩUsed (TV OUT)
20 VIDEO / Y input 1V(P-P) (Negative sync), 75 ΩUsed
21 COMMON GND --- Used
20 18 16 14 12 10 8 6 4 2
21 19 17 15 13 11 9 7 5 3 1
Pin assignment

1-6 (No.YA080)
SECTION 3
DISASSEMBLY
3.1 DISASSEMBLY PROCEDURE
3.1.1 REMOVING THE REAR COVER
(1) Unplug the power cord.
(2) Remove the 6 screws [A].
(3) Withdraw the REAR COVER toward you.
3.1.2 REMOVING THE MAIN PWB
• Remove the REAR COVER.
(1) Slightly raise the both sides of the MAIN PWB by hand and
withdraw the MAIN PWB backward.
(If necessary, take off the wire clamp, connectors etc.)
3.1.3 REMOVING THE SPEAKER
• Remove the REAR COVER.
(1) Remove the 4 screws [B].
(2) Remove the speaker toward you.
3.1.4 REMOVING THE FRONT AV JACK PWB
• Remove the REAR COVER.
• Remove the MAIN PWB.
(1) Remove the 2 screws [C].
(2) Remove the FRONT AV JACK PWB.
3.1.5 REMOVING THE HEADPHONE JACK PWB
• Remove the REAR COVER.
• Remove the MAIN PWB.
(1) Remove the 1 screw [D].
(2) Remove the HEADPHONE JACK PWB.
3.1.6 CHECKING THE PW BOARD
• To check the back side of the PW Board.
(1) Pull out the PW Board. (Refer to REMOVING THE MAIN
PWB).
(2) Erect the PW Board vertically so that you can easily check
the back side of the PWB.
CAUTION:
• When erecting the PW Board, 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.
3.1.7 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.YA080)1-7
A
B
CMAIN PWB
FRONT AV JACK PWB
HEADPHONE JACK
PWB
FUNCTION
BUTTON
SPEAKER
FRONT CABINET
BACK COVER
PICTURE TUBE
CRT SOCKET PWB
(Within MAIN PWB)
(x6)
(x4)
(x2)
D
(x1)

1-8 (No.YA080)
3.2 REPLACEMENT OF MEMORY IC
3.2.1 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.
3.2.2 PROCEDURE FOR REPLACING MEMORY IC SERVICE MENU
Fig.1
Fig.2
PROCEDURE
1. Power off
Switch the power off and unplug the power cord from the outlet
2. Replace IC.
Be sure to use memory IC written with the initial data values.
3. Power on
Plug the power cord into the outlet and switch the power on.
4. SERVICE MENU setting
(1) Press [MENU] key and, while the displayed MENU screen,
press [4], [7], [2], [5] key on the remote control unit or press
[MUTING] key and [INFORMATION] key at the
simultaneously.
(2) The SERVICE MENU screen of Fig. 1 will be displayed.
(3) Verify what to set in the SERVICE MENU, and set
whatever is necessary (Fig.1). Refer to the SERVICE
ADJUSTMENT for setting.
(4) Press the [STANDARD] key to exit SERVICE MENU.
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 after page.
Where these do not agree, refer to the OPERATING
INSTRUCTIONS (USER'S GUIDE) and set the items as
described.
JVCAK30/37 B20
OSD
IF1
IF2
IF3
IF4
AGC
VLIN
RGBH
VSOF
VPOF
: 1 1 AVL
POWER
MUTING
INFORMATION
NUMBER
STANDARD
COLOUR
MENU
VALUE
SELECT (+)
VALUE
SELECT (-)
ITEM
SELECT ( )
ITEM
SELECT ( )
SERVICE MENU SELECT KEY
AV

(No.YA080)1-9
3.3 SETTING OF THE LAST MEMORY FOR SHIPMENT
3.3.1 USER SETTING VALUES
3.3.2 SETTING APS BIT IN SERVICE MENU
(1) Press the [INFORMATION] and [MUTING] keys enter service menu in TV mode simultaneously. Service Menu will appear.
(2) Press the []/[] key to select TX1(TELETEXT OPTION).
(3) Press the [7] key to set APS bit. (After this, bit 7 of TX1 will be "1")
(4) Press [STANDARD] key to exit service mode.
NOTE : DO NOT TURN OFF THE TV BY USING POWER BUTTON ON THE FRONT PANEL.
Setting item Setting value Setting item Setting value
PICTURE MENU INSTALL
BRIGHTNESS These adjust are automatically
restored when APS bit in
service menu is set.
The procedure for setting APS
bit is described below.
PROGRAMME
Refer to the INSTRUCTION
BOOK
CONTRAST BAND
COLOUR CHANNEL
SHARPNESS SEARCH
HUE(only NTSC) FINE TUNING
MODE AUTO STORE
SOUND MENU FEATURE MENU
BALANCE Center SLEEP TIMER OFF
BASS Center CHILD LOCK OFF
TREBLE Center LANGUAGE ENGLISH
MODE MONO AV-1 OUTPUT TV
EFFECT OFF

1-10 (No.YA080)
3.4 REPLACEMENT OF CHIP COMPONENT
3.4.1 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.
3.4.2 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.
3.4.3 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

(No.YA080)1-11
SECTION 4
ADJUSTMENT
4.1 ADJUSTMENT PREPARATION
(1) You can make the necessary adjustments for this unit with
either the Remote Control Unit or with the adjustment tools
and parts as given below.
(2) Adjustment with the Remote Control Unit is made on the
basis of the initial setting values, however, the new setting
values which set the screen to its optimum condition may
differ from the initial settings.
(3) Make sure that AC power is turned on correctly.
(4) Turn on the power for set and test equipment before use,
and start the adjustment procedures after waiting at least
30 minutes.
(5) Unless otherwise specified, prepare the most suitable
reception or input signal for adjustment.
(6) Never touch any adjustment parts which are not specified
in the list for this adjustment - variable resistors,
transformers, condensers, etc.
(7) Presetting before adjustment.
Unless otherwise specified in the adjustment instructions,
preset the following functions with the remote control unit:
4.2 ADJUSTMENT EQUIPMENT
(1) DC voltmeter (or digital voltmeter)
(2) Signal generator (Pattern generator)
: [PAL / SECAM / NTSC]
(3) Remote control unit
4.3 ADJUSTMENT ITEM
• FOCUS ADJUSTMENT
• SCREEN ADJUSTMENT
• OSD HORIZONTAL POSITION ADJUSTMENT
• IF ADJUSTMENT
• AGC AUTOMATICALLY ADJUSTMENT
• DEFLECTION ADJUSTMENT
• WHITE BALANCE ADJUSTMENT
4.4 ADJUSTMENT LOCATIONS
Setting item Setting value
BRIGHTNESS
Center
CONTRAST
COLOUR
SHARPNESS
FUSE
IC500
EEP ROM
IC501
MICOM
TUNER
AV-1(SCART)
FBT
FRONT
UPPER:FOCOUS
LOWER:SCREEN
MAIN
SW
LED
REMOCON
RECEIVER VOL.
(+) (-)(+) (-)
CH. / PROG.
MENU
PL602
MAIN PWB
TOP
FRONT AV JACK PWB
HEADPHONE JACK PWB
HP
TOP

1-12 (No.YA080)
4.5 BASIC OPERATION OF SERVICE MODE
4.5.1 HOW TO ENTER SERVICE MODE
(1) Press the MENU key.
(2) MENU screen will be displayed (fig.1).
Fig.1
(3) While the MENU screen is displayed , press the [4], [7], [2],
[5] key or [INFORMATION] key and [MUTING] key
simultaneously.
(4) The SERVICE MENU screen will be displayed (fig.2).
Fig.2
4.5.2 SELECTION OF ADJUSTMENT ITEMS
(1) Enter the SERVICE MODE.
(2) Press the []/[] key to select the adjustment item.
(3) Press the []/[] key to set the setting value.
4.5.3 HOW TO EXIT SERVICE MODE
(1) Press the [STANDARD] key.
4.5.4 HOW TO ENTER THE GEOMETRY MENU
• This model is built-in GEOMETRY MENU for geometry
adjustment.
(1) Enter the SERVICE MODE.
(2) Press the [GREEN] key, geometry menu appears (Fig. 3).
(3) Press the []/[] key and select the adjustment item.
(4) Press the []/[] key and set the setting value.
Fig.3
MENU
MENU SCREEN
SOUND
PICTURE
FEATURE
INSTALL.
PROGRAM.
ADJUSTMENT ITEM SETTING VALUE
JVCAK30/37 B20
SERVICE MENU
OSD
IF1
IF2
IF3
IF4
AGC
VLIN
RGBH
VSOF
VPOF
: 1 1 AVL
GEOMETRY
GEOMETRY MENU
VSIZ
VPOS
VSCO
VCCO
HSIZ
HPOS
HPIN
AUTO
ADJUSTMENT ITEM SETTING VALUE
FUNCTION
Key
AV Key
INFORMATION
Key
NUMBER Key
STANDARD
Key
COLOUR Key
MENU Key
REMOTE CONTROL UNIT key NAME
FUNCTION OF COLOUR key
RED key :
It switches the AVL to ON or OFF mode on service menu.
AVL word is visible on service menu when AVL is on.
GREEN key :
It switches to GEOMETRY adjust menu. Geometry
of the picture is adjusted in this menu.
YELLOW key :
It switches to VERTICAL SCAN DISABLE mode.
It is useful to adjust screen voltage.
BLUE key :
It is used to adjust AGC and IF automatically on service menu.

(No.YA080)1-13
4.5.5 ADJUSTMENT ITEM
4.5.5.1 SERVICE MENU 4.5.5.2 GEOMETRY MENU
Adjustment
item Description
OSD HORIZONTAL POSITION OF OSD
IF1 IF COARSE ADJUSTMENT
IF2 IF FINE ADJUSTMENT
IF3 IF COARSE ADJUSTMENT FOR L-PRIME
IF4 IF FINE ADJUSTMENT FOR L-PRIME
AGC AUTOMATIC GAIN CONTROL
VLIN VERTICAL LINEARITY
RGBH RGB MODE HORIZONTAL SHIFT OFFSET
VSOF VERTICAL SIZE OFFSET for 60Hz
VPOF VERTICAL POSITION OFFSET for 60Hz
HSOF HORIZONTAL SIZE OFFSET for 60Hz
HPOF HORIZONTAL POSITION OFFSET for 60Hz
HTOF HORIZONTAL TRAPEZOID OFFSET for 60Hz
WR WHITE POINT ADJUSTMENT FOR RED
WG WHITE POINT ADJUSTMENT FOR GREEN
WB WHITE POINT ADJUSTMENT FOR BLUE
BR BIAS FOR RED
BG BIAS FOR GREEN
APR AUTOMATIC RGB PEAK REGULATION THRESHOLD
BRI BRIGHTNESS
CON CONTRAST
COL COLOUR
SHA SHARP
HUE HUE
VOL VOLUME
WR-R WHITE POINT ADJUSTMENT for RED (RGBmode)
WG-R WHITE POINT ADJUSTMENT for GREEN (RGBmode)
WB-R WHITE POINT ADJUSTMENT for BLUE (RGBmode)
FMP1 FM PRESCALER WHEN AVL IS OFF
NIP1 NICAM PRESCALER WHEN AVL IS OFF
SCP1 SCART PRESCALER WHEN AVL IS OFF
SEC1 SECAM PRESCALER WHEN AVL IS OFF
FMP2 FM PRESCALER WHEN AVL IS ON
NIP2 NICAM PRESCALER WHEN AVL IS ON
SCP2 SCART PRESCALER WHEN AVL IS ON
SEC2 SECAM PRESCALER WHEN AVL IS ON
F1H
HIGH BYTE OF VHF1-VHF3 CROSS-OVER FREQUENCY
F1L LOW BYTE OF VHF1-VHF3 CROSS-OVER FREQUENCY
F2H HIGH BYTE OF VHF3-UHF CROSS-OVER FREQUENCY
F2L LOW BYTE OF VHF3-UHF CROSS-OVER FREQUENCY
BS1 BAND SWITCHING BYTE FOR VHF1
BS2 BAND SWITCHING BYTE FOR VHF3
BS3 BAND SWITCHING BYTE FOR UHF
CB CONTROL BYTE
OP1 PERIPHERAL OPTIONS
OP2 RECEPTION STANDARD OPTIONS
OP3 VIDEO OPTIONS
OP4 TV FEATURES
OP5 CHANNEL TABLES
TX1 TELETEXT OPTIONS
GEOM GEOMETRY OPTIONS
OP8 PIP PRESET CHANGE
Adjustment
item Description
VSIZ VERTICAL SIZE for 50Hz
VPOS VERTICAL POSITION for 50Hz
VSCO VERTICAL S-CORRECTION for 50Hz
VCCO VERTICAL CORNER CORRECTION for 50Hz
HSIZ HORIZONTAL SIZE for 50Hz
HPOS HORIZONTAL POSITION for 50Hz
HPIN HORIZONTAL PINCUSHION for 50Hz
HCCO HORIZONTAL CORNER CORRECTION for 50H
HTRP HORIZONTAL TRAPEZOID for 50Hz
VZSZ VERTICAL ZOOM SIZE for 50Hz

1-14 (No.YA080)
4.6 ADJUSTMENTS PROCEDURE
4.6.1 FOCUS ADJUSTMENT
4.6.2 SCREEN ADJUSTMENT
4.6.3 OSD ADJUSTMENT
Item Measuring
instrument Test point Adjustment part Description
FOCUS
adjustment
Signal
generator
Remote
control unit
FOCUS VR
[On the FBT]
(1) Receive a PAL crosshatch signal.
(2) Adjust FOCUS VR on the FBT as thin as possible.
FBT
FOCUS VR
SCREEN VR
Item Measuring
instrument Test point Adjustment part Description
SCREEN
adjustment
Remote
control unit
SCREEN VR
[On the FBT]
(1) Enter the SERVICE MODE.
(2) Press the [YELLOW] key to disable vertical scan.
(3) Adjust SCREEN VR. on the FBT as thin as possible.
(4) Press [YELLOW] key again to enable vertical scan.
(5) Press [STANDARD] key to leave service menu.
FBT
FOCUS VR
SCREEN VR
Item Measuring
instrument Test point Adjustment part Description
OSD
HORIZONTAL
POSITION
adjustment
Remote
control unit
OSD (1) Enter the SERVICE MODE.
(2) Select OSD with the []/[] key.
(3) Adjust the OSD horizontal position with the []/[]
key, which shifts the reference bar on the bottom of
the SERVICE MENU horizontally, so that the OSD is
positioned on the screen center. (X=X')
JVCAK30/37 B20
Screen size
Reference ba
r
SERVICE MENU SCREEN
OSD
IF1
IF2
IF3
IF4
AGC
VLIN
RGBH
VSOF
VPOF
: 1 1 AVL
XX'

(No.YA080)1-15
4.6.4 IF ADJUSTMENT
4.6.5 AGC AUTOMATICALLY ADJUSTMENT
4.6.6 DEFLECTION ADJUSTMENT
Item Measuring
instrument Test point Adjustment part Description
IF adjustment Remote
control unit
IF1
IF2
IF3
IF4
(1) Receive a PAL colour bar pattern.
(2) Enter the SERVICE MODE.
(3) Select IF 1 with the []/[] key.
(4) Press [BLUE] key during IF 1 is highlighted, IF 1 and
IF 2 values are adjusted automatically by software.
(5) If the standard is L-prime, IF 3 and IF 4 values are
adjustment automatically when [BLUE] key is
pressed during IF 1 is highlighted.
Item Measuring
instrument Test point Adjustment part Description
AGC
AUTOMATICALLY
adjustment
Remote
control unit
AGC (1) Receive a 60dBµV RF signal level.
(2) Enter the SERVICE MODE.
(3) Select AGC with the []/[] key.
(4) Press [BLUE] key.
(5) The adjustment will be done automatically by
software.
(6) See the AGC indicator on SERVICE MENU, it must
be "1".
(7) Check that picture is normal at 90dBµV signal level.
Item Measuring
instrument Test point Adjustment part Description
VERTICAL
SIZE OFFSET
(60Hz)
adjustment
Signal
generator
Remote
control unit
VSOF (1) Receive a NTSC crosshatch pattern of vertical
frequency 60Hz.
(2) Enter the SERVICE MODE.
(3) Select VSOF with the []/[] key.
(4) Adjust VSOF with the []/[] key until the horizontal
black lines on both the upper and lower part of the
pattern become very close to the upper and lower
horizontal sides of picture size and nearly about to
disappear.
(5) Check and readjust VSOF item if the adjustment
becomes improper after some other geometric
adjustments are done.
JVCAK30/37 B20
OSD
IF1
IF2
IF3
IF4
AGC
VLIN
RGBH
VSOF
VPOF
: 1 1 AVL
IF INDICATOR AGC INDIXATOR NON
:11
Screen
size
Very close
Very close
Picture
size
100%

1-16 (No.YA080)
VERTICAL
POSITION
OFFSET
(60Hz)
adjustment
Signal
generator
Remote
control unit
VPOF (1) Receive a NTSC circle pattern of vertical frequency
60Hz.
(2) Enter the SERVICE MODE.
(3) Select VPOF with the []/[] key.
(4) Adjust VPOF with the []/[] key until the picture is
vertically centered. (C=D)
(5) Check and readjust vertical position item if the
adjustment becomes improper after some other
geometric adjustments are done.
HORIZONTAL
POSITION
OFFSET
(60Hz)
adjustment
Signal
generator
Remote
control unit
HPOF (1) Receive a NTSC circle pattern signal of vertical
frequency 60Hz.
(2) Enter the SERVICE MODE.
(3) Select HPOF with the []/[] key.
(4) Adjust HPOF with the []/[] key until the circle
pattern is horizontally centered. (E=F)
(5) Check and readjust a horizontal position item if the
adjustment becomes improper after some other
geometric adjustments are done. Press the [MENU]
key and memorize the set value.
VERTICAL
SIZE
(50Hz)
adjustment
Signal
generator
Remote
control unit
VSIZ (1) Receive a PAL crosshatch pattern of vertical
frequency 50Hz.
(2) Enter the SERVICE MODE.
(3) Press the [GREEN] key to enter the GEOMETRY
MENU.
(4) Select VSIZ (Vertical size) with the []/[] key.
(5) Adjust VSIZ with the []/[] key until the horizontal
black lines on both the upper and lower horizontal
sides of picture size and nearly about to disappear.
(6) Check and readjust VSIZ item if the adjustment
becomes improper after some other geometric
adjustments are done.
Item Measuring
instrument Test point Adjustment part Description
C
D
EF
Screen
size
Very close
Very close
Picture
size
100%

(No.YA080)1-17
VERTICAL
POSITION
(50Hz)
adjustment
Signal
generator
Remote
control unit
VPOS (1) Receive a PAL circle pattern signal of vertical
frequency 50Hz.
(2) Enter the GEOMETRY MODE.
(3) Select VPOS (Vertical position) with the []/[] key.
(4) Adjust VPOS with the []/[] key until the circle
pattern is vertically centered. (A=B)
(5) Check and readjust VPOS item if the adjustment
becomes improper after some other geometric
adjustments are done.
HORIZONTAL
POSITION
(50Hz)
adjustment
Signal
generator
Remote
control unit
HPOS (1) Receive a PAL circle pattern signal of vertical
frequency 50Hz.
(2) Enter the GEOMETRY MODE.
(3) Select HPOS (Horizontal position) with the []/[]
key.
(4) Adjust HPOS with the []/[] key until the circle
pattern is horizontally centered. (C=D)
(5) Check and readjust HPOS item if the adjustment
becomes improper after some other geometric
adjustments are done.
VERTICAL
LINEARITY
adjustment
Signal
generator
Remote
control unit
VLIN (1) Receive a PAL circle pattern .
(2) Enter the SERVICE MODE.
(3) Select VLIN with the []/[] key.
(4) Adjust VLIN with the []/[] key until circle as round
as possible.
Item Measuring
instrument Test point Adjustment part Description
A
B
CD

1-18 (No.YA080)
4.6.7 WHITE BALANCE ADJUSTMENT
RGB MODE
HORIZONTAL
SHIFT
adjustment
Signal
generator
Remote
control unit
RGBH (1) Input R/G/B circle pattern signal via video input
terminal.
(2) Press [AV] key, force the TV to RGB mode.
(3) Enter the SERVICE MODE.
(4) Select RGBH with the []/[] key.
(5) Adjust RGBH with the []/[] key until the circle
pattern is horizontally centered. (A=B)
(6) Check and readjust RGBH item if the adjustment
becomes improper after some other geometric
adjustments are done.
Item Measuring
instrument Test point Adjustment part Description
AB
Item Measuring
instrument Test point Adjustment part Description
WHITE
BALANCE
(Low light)
adjustment
Signal
generator
Remote
control unit
WR
WG
WB
(1) Receive a black & white signal (colour off).
(2) Enter the SERVICE MODE.
(3) Select WR / WG / WB with the []/[] key
respectively.
(4) Adjust WR / WG / WB with the []/[] key,
respectively, until the white part turns to pure white
without any other colour.
WHITE
BALANCE
(High light)
adjustment
Signal
generator
Remote
control unit
BR
BG
(1) Receive a black & white signal (colour off).
(2) Enter the SERVICE MODE.
(3) Select BR / BG with the []/[] key respectively.
(4) Adjust BR / BG with the []/[] key, respectively
until the white part of screen make white colour.

(No.YA080)1-19
SECTION 5
TROUBLESHOOTING
This service manual does not describe TROUBLESHOOTING.

(No.YA080)
AV & MULTIMEDIA COMPANY VIDEO DISPLAY CATEGORY 12, 3-chome, Moriya-cho, kanagawa-ku, Yokohama, kanagawa-prefecture, 221-8528, Japan
Victor Company of Japan, Limited
VPT
Printed in Japan