JVC AV-21KT1BEF User manual

SERVICE MANUAL
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LIMITED No.52134
2003/10
COLOUR TELEVISION
52134200310 AV-21KT1BEF/A,/B, AV-21KT1SEF/A,/B,
AV-21KT1BNF/A,/B, AV-21KT1SNF/A,/B,
AV-21KT1BPF/A,/B, AV-21KT1SPF/A,/B
TABLE OF CONTENTS
1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20
RM-C1100TV

1-2 (No.52134)
SPECIFICATION
Design & specifications are subject to change without notice.
Item Content
AV-21KT1BEF
AV-21KT1SEF AV-21KT1BNF AV-21KT1SNF AV-21KT1BPF AV-21KT1SPF
Dimensions ( W ×H ×D ) 61cm ×45cm ×48cm
Mass 21kg
TV RF System B/G, D/K, K1 B/G B/G, L/L'
Colour System TV Mode PAL / SECAM PAL PAL / SECAM
Video Mode PAL / SECAM / NTSC 3.58 /
NTSC 4.43 PAL / NTSC 3.58 / NTSC 4.43 PAL / SECAM / NTSC 3.58 / NTSC 4.43
Sound System NICAM / A2 (Germany system)
Teletext System FLOF (Fastext) / TOP (German system)
Number of CH memory position 100ch
Receiving
Frequency VHF Low 46.25MHz ~ 168.25MHz
VHF High 175.25MHz ~ 463.25MHz
UHF 471.25MHz ~ 863.25MHz
CATV BG : S01-S41 & S75-S79
DK : S01-S41 BG : S01-S41 & S75-S79 BG : S01-S41 & S75-S79 L : S01-S41 & S75-S77
Intermediate
Frequency VIF SIF 38.9MHz (B/G, D/K, L) / 33.9MHz (L') 33.4MHz (5.5MHz:B/G) / 32.9MHz (6.0MHz:D/K) / 32.4MHz (6.5MHz:L) / 40.4MHz (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)
Aerial Input Terminal 75Ωunbalanced, coaxial
Picture Tube Visible size : 51cm (Measured diagonally)
High Voltage 25.3kV
Speaker 5.7cm ×16cm oval type ×2
Audio Output 6.5W + 6.5W
Input Video
S-Video
Audio (L/R)
1V(p-p) 75Ω
Y : 1V(p-p) positive
C : 0.286V(p-p)
500mV(rms) (-4dBs), High impedance (RCA pin jack ×2)
Output Video
Audio (L/R) 1V(p-p) 75Ω 500mV(rms), Low impedance
Input Terminal Front Side
Rear Side F-AV (Video / Audio) AV-1 (Video / Audio / RGB)
AV-2 (Video / Audio / RGB) : AV-2S (Video / Audio / RGB / S-VIDEO)
Output Terminal Right Side
Rear Side Headphone Jack (Stereo mini jack Ø3.5mm ×1) AV-1 (Video / Audio)
AV-2 (Video / Audio)
Remote Control Unit VE-30017763 (RM-C1100), (AA/R06 dry battery ×2)

(No.52134)1-3
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) 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.52134)
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
2.1 21-pin Euro connector (SCART) : AV-1 / AV-2 (AV-2S)
(P-P= Peak to Peak, B-W= Blanking to white peak)
Pin No. Signal Designation Matching Value AV-1 AV-2 (AV-2S)
1 AUDIO R output 500mV(rms) (Nominal), Low impedance Used Used
2 AUDIO R input 500mV(rms) (Nominal), High impedance Used (R1) Used (R2)
3 AUDIO L output 500mV(rms) (Nominal), Low impedance Used Used
4 AUDIO GND --- Used Used
5 GND (B) --- Used Used
6 AUDIO L input 500mV(rms) (Nominal), High impedance Used (L1) Used (L2)
7 B input 700mV(B-W), 75 ΩUsed Used
8 FUNCTION SW
(SLOW SW) Low : 0V-3V, High : 8V-12V, High impedance Used Used
9 GND (G) --- Used Used
10 SCL / T-V LINK --- Not used Used (SCL / TV-LINK)
11 G input 700mV(B-W), 75 ΩUsed Used
12 SDA3 --- Not used Not used
13 GND (R) --- Used Used
14 GND (YS) --- Used Used
15 R / C input R : 700mV(B-W), 75 Ω
C : 300mV(P-P), 75 ΩUsed (R) Used (C2/R)
16 Ys input
(FAST SW) Low : 0V-0.4V, 75 Ω High : 1V-3V, 75 ΩUsed Used
17 GND (VIDEO output) --- Used Used
18 GND (VIDEO input) --- Used Used
19 VIDEO output 1V(P-P) (Negative sync), 75 ΩUsed Used
20 VIDEO / Y input 1V(P-P) (Negative sync), 75 ΩUsed Used
21 COMMON GND --- Used Used
20 18 16 14 12 10 8 6 4 2
21 19 17 15 13 11 9 7 5 3 1
[Pin assignment]

(No.52134)1-5
2.2 FEATURES
• It is a remote controlled color television.
• 100 programs from VHF, UHF bands or cable channels can be
preset.
• It can tune cable channels.
• Controlling the TV is very easy by its menu driven system.
• It has two Euroconnector sockets for external device (such as
video recorder, video games, audio set, etc.)
• Front AV Input available.
• Stereo sound systems (German + Nicam) are available.
• Full function Teletext (Fastext, Toptext).
• 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.
2.3 MAIN DIFFERENCE LIST
Part Name [/A models] [/B models]
Model name AV-21KT1BEF/A
AV-21KT1BNF/A
AV-21KT1BPF/A
AV-21KT1SEF/A
AV-21KT1SNF/A
AV-21KT1SPF/A
AV-21KT1BEF/B
AV-21KT1BNF/B
AV-21KT1BPF/B
AV-21KT1SEF/B
AV-21KT1SNF/B
AV-21KT1SPF/B
PICTURE TUBE VE-LG320X65 VE-THO13X191
Part Name AV-21KT1BEF AV-21KT1BNF
AV-21KT1BPF
AV-21KT1SEF
AV-21KT1SNF
AV-21KT1SPF
COLOUR BLACK SILVER
FRONT CABINET VE-20122422 VE-20122430
REAR COVER VE-20112186 VE-20121199
FUNCTION BUTTON VE-20112187 VE-20121204
POWER BUTTON VE-20112223 VE-20121207
JVC LOGO VE-40013592 VE-40013593
Part Name AV-21KT1BEF
AV-21KT1SEF AV-21KT1BNF AV-21KT1SNF AV-21KT1BPF AV-21KT1SPF
MAIN PWB ASSY VE-20124223 [/A]
VE-20133635 [/B] VE-20124225 [/A] VE-20129865 [/B] VE-20121220 [/A] VE-20129808 [/B]
INSTRUCTION BOOK VE-50036404 VE-50036402 VE-50036403
RATING LABEL VE-20122445 VE-20122419 VE-20122423
CARTON BOX VE-50036605 VE-50036586 VE-50036588

1-6 (No.52134)
SECTION 3
DISASSEMBLY
3.1 DISASSEMBLY PROCEDURE
3.1.1 REMOVING THE REAR COVER
(1) Unplug the power cord.
(2) Remove the 7 screws [A] as shown in the Fig. 1.
(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 chassis 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], and remove speaker as shown
in Fig. 1.
(2) Remove the speaker.
(3) Remove the other side speaker by same procedure.
3.1.4 REMOVING THE FRONT AV PWB
• Remove the REAR COVER.
• Remove the MAIN PWB.
(1) Remove the 2 screws marked [C] as shown in Fig. 1.
(2) Remove the FRONT AV PWB.
3.1.5 REMOVING THE HEADPHONE PWB
• Remove the REAR COVER.
• Remove the MAIN PWB.
(1) Remove the 1 screw [D] as shown in Fig. 1.
(2) Remove the HEADPHONE 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 PW Board.
3.1.7 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 PW board.
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 togeth-
er.
Should it be inadvertently removed, be sure to tie the wires
with a new cable tie.

(No.52134)1-7
Fig.1
A
(X7)
B(X4)
D(X1)
B(X4)
C(X2)
MAIN PWB
SPEAKER
HEADPHONE
PWB
FRONT CABINET
FRONT AV PWB
CRT
REAR COVER

1-8 (No.52134)
3.2 REPLACEMENT OF CHIP COMPONENT
3.2.1 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.
3.2.2 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.
3.2.3 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.52134)1-9
3.3 REPLACEMENT OF MEMORY IC
3.3.1 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.
3.3.2 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 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.
Fig.1
Fig.2
JVCAK30/37 B20
OSD
IF1
IF2
IF3
IF4
AGC
VLIN
RGBH
VSOF
VPOF
: 1 1 AVL
SERVICE MENU
POWER
MUTING
INFORMATION
NUMBER
STANDARD
COLOUR
MENU
VALUE
SELECT (+)
VALUE
SELECT (-)
ITEM
SELECT ( )
ITEM
SELECT ( )
SERVICE MENU SELECT KEY
AV

1-10 (No.52134)
3.4 SETTING OF THE LAST MEMORY FOR SHIPMENT
3.4.1 USER SETTING VALUES
3.4.2 SETTING APS BIT IN SERVICE MENU
(1) Enter service menu in TV mode by pressing "INFORMATION" and "MUTING"keys simultaneously. Service Menu will appear.
(2) Select TX1(TELETEXT OPTION) by pressing Up/Down keys on remote control unit.
(3) Press the 7 key on remote control unit to set APS bit. (After this, bit 7 of TX1 will be "1")
(4) Press STANDARD key on remote control unit 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
SOUND MENU FEATURE MENU
BALANCE CENTER SLEEP TIMER OFF
BASS CENTER CHILD LOCK OFF
TREBLE CENTER LANGUAGE ENGLISH
MODE STEREO AV-2 OUTPUT TV
EFFECT OFF
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

(No.52134)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 re-
ception or input signal for adjustment.
(6) Never touch any adjustment parts which are not specified
in the list for this adjustment - variable resistors, transform-
ers, 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 CIRCUIT ADJUSTMENT
• GEOMETRY MENU ADJUSTMENT
• WHITE BALANCE ADJUSTMENT
4.4 ADJUSTMENT LOCATIONS
BRIGHTNESS CENTER
CONTRAST
COLOUR
SHARPNESS
FUSE
12.5A
IC500
EEP ROM
IC501
MICOM IC403
IC700
TUNER
SCART
HVT
FBT
FRONT FRONT
TOP
SIDE
UPPER:FOCOUS
LOWER:SCREEN
MAIN
SW
LED
REMOCON
RECEIVER VOL.
(+) (-)(+) (-)
CH. / PROG.
MENU
MAIN PWB
DEG
COIL
POWER
CORD
HV
PL405
PL602
PL302
FRONT AV PWB
HEADPHONE PWB
CRT SOCKET PWB MAIN PWB
HP

1-12 (No.52134)
4.5 BASIC OPERATION OF SERVICE MENU
4.5.1 HOW TO ENTER SERVICE MENU
(1) Press the MENU key.
(2) MENU screen of (fig.1) will be displayed.
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 of (Fig.2) will be displayed.
Fig.2
4.5.2 SELECTION OF ADJUSTMENT ITEMS
(1) Enter the SERVICE MENU
(2) Press the [/] key and select the ADJUSTMENT ITEM.
(3) Press the [/] key and set the SETTING VALUE.
4.5.3 HOW TO EXIT SERVICE MODE
(1) Press the [STANDARD] Key on REMOTE CONTROL
UNIT.
4.5.4 HOW TO ENTER THE GEOMETRY MENU
• This model is built-in GEOMETRY MENU for geometry
adjustment.
(1) Enter the SERVICE MENU
(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.52134)1-13
4.5.5 ADJUSTMENT ITEM
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

1-14 (No.52134)
4.5.6 GEOMETRY MENU
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

(No.52134)1-15
4.6 ADJUSTMENT PROCEDURE
4.6.1 FOCUS / SCREEN ADJUSTMENT
4.6.2 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 cross-hatch signal. (2) Adjust FOCUS VR on the FBT as thin as possible.
SCREEN
adjustment Remote control unit SCREEN VR [On the FBT] (1) Enter the SERVICE MENU. (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.
Item Measuring
instrument Test point Adjustment part Description
HORIZONTAL
POSITION OF
OSD
adjustment
Remote
control unit OSD (1) Enter the SERVICE MENU. (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')
FBT
FOCUS VR
SCREEN VR
FBT
FOCUS VR
SCREEN VR
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'

1-16 (No.52134)
4.6.3 IF ADJUSTMENT
4.6.4 AGC AUTOMATICALLY ADJUSTMENT
4.6.5 DEFLECTION CIRCUIT ADJUSTMENT
Item Measuring
instrument Test point Adjustment part Description
IF adjustment Remote
control unit IF 1 IF 2
IF 3
IF 4
(1) Receive a PAL colour bar pattern.
(2) Enter the SERVICE MENU.
(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) Enter the SERVICE MENU. (2) Receive a 60dBmV RF signal level.
(3) Select AGC with the [/] key.
(4) Press [BLUE] key on the remote control unit.
(5) Then 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 90dBmV signal level.
Item Measuring
instrument Test point Adjustment part Description
VERTICAL
LINEARITY
adjustment
Signal
generator
Remote
control unit
VLIN (1) Receive a PAL B/G circle pattern.
(2) Enter the SERVICE MENU.
(3) Select VLIN with the [/] key.
(4) Adjust VLIN with the [/] key until circle as round
as possible.
JVCAK30/37 B20
OSD
IF1
IF2
IF3
IF4
AGC
VLIN
RGBH
VSOF
VPOF
: 1 1 AVL
IF INDICATOR AGC INDICATOR NONE
: 1 1

(No.52134)1-17
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 on the remote control unit, force the
TV to RGB mode.
(3) Enter the SERVICE MENU.
(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.
VERTICAL SIZE
OFFSET
adjustment
(60Hz)
Signal
generator
Remote
control unit
VSOF (1) Receive a NTSC-M cross-hatch pattern of vertical
frequency 60Hz.
(2) Enter SERVICE MENU.
(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 opper anr lower
horizontal sides of picture size and nearly about to
disappear.
(5) Check and readjust VSOF item if the adjustment
bocomes improper after some other geometric
adjustments are done.
VERTICAL
POSITION
OFFSET
adjustment
(60Hz)
Signal
generator
Remote
control unit
VPOF (1) Receive a NTSC-M circle pattern of vertical
frequency 60Hz.
(2) Enter the SERVICE MENU.
(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.
Item Measuring
instrument Test point Adjustment part Description
AB
Screen
size
Very close
Very close
Picture
size
100%
C
D

1-18 (No.52134)
4.6.6 GEOMETRY MENU ADJUSTMENT
HORIZONTAL
POSITION
OFFSET
adjustment
(60Hz)
Signal
generator
Remote
control unit
HPOF (1) Receive a NTSC-M circle pattern signal of vertical
frequency 60Hz.
(2) Enter the SERVICE MENU.
(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.
Item Measuring
instrument Test point Adjustment part Description
VERTICAL SIZE
adjustment
(50Hz)
Signal
generator
Remote
control unit
VSIZ (1) Receive a PAL B/G cross-hatch pattern of vertical
frequency 50Hz.
(2) Enter the SERVICE MENU.
(3) Press the [GREEN] key then 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.
VERTICAL
POSITION
adjustment
(50Hz)
Signal
generator
Remote
control unit
VPOS (1) Receive a PAL B/G circle pattern signal of vertical
frequency 50Hz.
(2) Enter the GEOMETRY MENU.
(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.
Item Measuring
instrument Test point Adjustment part Description
EF
Screen
size
Very close
Very close
Picture
size
100%
A
B

(No.52134)1-19
4.6.7 WHITE BALANCE ADJUSTMENT
HORIZONTAL
POSITION
OFFSET
adjustment
(50Hz)
Signal
generator
Remote
control unit
HPOS (1) Receive a PAL B/G circle pattern signal of vertical
frequency 50Hz.
(2) Enter the GEOMETRY MENU.
(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.
Item Measuring
instrument Test point Adjustment part Description
WHITE
BALANCE
adjustment
(Low light)
Signal
generator
Remote
control unit
WR
WG
WB
(1) Receive a black & white signal (colour off).
(2) Enter the SERVICE MENU.
(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
adjustment
(High light)
Signal
generator
Remote
control unit
BR
BG (1) Receive a black & white signal (colour off). (2) Enter the SERVICE MENU.
(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.
Item Measuring
instrument Test point Adjustment part Description
CD

1-20 (No.52134)
SECTION 5
TROUBLESHOOTING
This service manual does not describe TROUBLESHOOTING.