Sharp VT-G14 User manual

1
VT-G14
VT-G21
VIDEO TV
RATING 110-240V(AUTO.) ~ 50/60 Hz
POWER CONSUMPTION 112 W
SERIAL NO. Jxxxxxxxxx
SHARP CORPORATION
In the interests of user-safety (Required by safety regulations in some countries) the set should be restored to its
original condition and only parts identical to those specified should be used.
SHARP CORPORATION
TV/VCR COMBINATION
TELEVIDEO
Chassis No. VP-7
MODELS
WARNING
The chassis in this receiver is partially hot. Use an isolation transformer between the line cord plug and power receptacle,
when servicing this chassis.
To prevent electric shock, do not remove cover.
No user — serviceable parts inside. Refer servicing to qualified service personnel.
VT-G14
VT-G21
SERVICE MANUAL
S11N9VT-G14//
ËFull Auto Search Tuning System
ËOn Screen Digital Channel/Sound Level/Tuning Display,
Control (Contrast, Colour, Brightness, Tint, Sharpness,
White temp) Symbol and Level
ËBlue Back Off Timer
Ë39 Key, Wireless Remote Control Unit
ËChannel Skip
ËHigh Speed and Double Speed Video Search System
»PAL/MESECAM : 3 times/7 times (SP/LP)
»NTSC : 3 times/5 times (SP/LP)
5 times/15 times (EP)
VT-G14 VT-G21
FEATURE
ËDPSS (Digital Program Search System)
ËQuick Start Playback with Full Loading System
ËDigital Automatic Tracking Control
ËAutomatic Playback Function
ËAHC (Automatic Head Cleaning System)
ËSharp Super Picture
Ë345 Times Hi-Speed FF/REW
MODEL VT-G21
CAUTION : DANGEROUS
VOLTAGE INSIDE
TO PREVENT ELECTRIC SHOCK, DO NOT
REMOVE COVER. NO USER-SERVICEABLE
PARTS INSIDE. REFER SERVICING TO
QUALIFIED SERVICE PERSONNEL.
Example of suffix symbol:
The component parts of this model are partially
differentdependingon theirsuffix symbols.Before
servicing the units, be sure to check the suffix
symbol on the model label that is applied on the
back of the unit.
Suffix "J" for Russia

2
VT-G14
VT-G21
CONTENTS
»SPECIFICATIONS......................................................... 3
»IMPORTANT SERVICE NOTES.................................... 4
»LOCATION OF USER'S CONTROL.............................. 5
»DISASSEMBLY AND REASSEMBLY ............................ 7
»ADJUSTMENT OF THE TV ELECTRICAL
CIRCUITRY ................................................................. 10
»PRECAUTIONS IN REASSEMBLING......................... 24
»FUNCTION OF MAJOR MECHANICAL PARTS ......... 25
»ADJUSTMENT, REPLACEMENTAND
ASSEMBLY OF MECHANICAL UNITS ....................... 27
»ADJUSTMENT OF THE VCR ELECTRICAL
CIRCUITRY ................................................................. 46
»TROUBLESHOOTING ................................................ 48
»CHASSIS LAYOUT...................................................... 68
»BLOCK DIAGRAM OF TV SECTION .......................... 70
»DESCRIPTION OF TV SECTION
SCHEMATIC DIAGRAM .............................................. 74
»SOLID STATE DEVICE BASE DIAGRAM ................... 75
»WAVEFORMS ............................................................. 76
»BLOCK DIAGRAM OF VCR SECTION ....................... 90
»DESCRIPTION OF VCR SECTION
SCHEMATIC DIAGRAM .............................................. 99
»PRINTED WIRING BOARD ASSEMBLIES ............... 106
»REPLACEMENT PARTS LIST ...................................114
»PACKING OF THE SET ............................................ 134
Page Page

3
VT-G14
VT-G21
SPECIFICATIONS
ËOUTLINE OF THE PRODUCT
Power Source: 110~240 V AC, 50/60 Hz
Power Consumption: VT-G14 : 94 W
VT-G21 : 112W
Receiving Broadcast Standard: B/G, I, D/K, M
Receiving Channel: VHF; 1A~S36
UHF; S37~C57
Receiving System: Sound; 5.5/6.0/6.5/4.5 MHz
Colour; PAL/SECAM/NTSC
Antenna Input Impedance: VHF/UHF;75 ohm Unbalanced (DIN)
Video Signal: Input; 0.5~2.0 Vp-p/75 ohm (RCA)
Output; 1.0 Vp-p/75 ohm (RCA)
Audio Signal: Input; 0.5 Vrms/10k ohm (RCA)
Output; 0.5 Vrms/1k ohm (RCA) (54% MOD)
Temperature: Operation; 5°C to 40°C
Storage; -10°C to 60°C
Dimensions (Approx.): VT-G14 : 378 mm (W) ×387 mm (H) ×384 mm (D)
VT-G21 : 505 mm (W) ×503 mm (H) ×478 mm (D)
Weight (Approx.): VT-G14 : 12.7 kg
VT-G21 : 23.5 kg
Cabinet Material: Plastic
Accessories: Operation Manual
Infrared Remote Control Unit
Dry Batteries, Type AA (×2 pcs.)
ËTV SECTION
Viewing Area: VT-G14 : 33.54 cm Diagonal Measurement
VT-G21 : 50.8 cm Diagonal Measurement
Picture Power: VT-G14 : 22.0 kV at 800 µA Beam Current
VT-G21 : 25.0 kV at 1100 µA Beam Current
Speaker Output: VT-G14 : 3.0 W at Max. (5×9 cm oval type ×1pc.)
VT-G21 : 3.0 W at Max. (5×9 cm oval type ×2pcs.)
Picture Tube: Type; VT-G14 : VB370BVBK1S-S (Tint Tube)
VT-G21 : VB540ADAC1S*S (Tint Tube)
Heater; VT-G14 : 6.3 V, 300 mA
VT-G21 : 6.3 V, 600 mA
Focus; High Bi-Potential Electrostatic
ËVCR SECTION
Outline: VHS Video System Colour Video Cassette Recorder
Format: VHS PAL/NTSC Standard
Video Recording System: Rotary Slant Azimuth 2-Head Helical Scan System
Luminance: FM Recording
Chrominance: Low Frequency Converted Direct Recording
Video Signal System: PAL/SECAM(MESECAM Rec)/NTSC 3.58MHz Colour
Cassette Tape: VHS Type Video Cassette Tape
Tape Width: 12.7 mm
Tape Speed: PAL ; 23.39 mm/s (SP), 11.70 mm/s (LP)
NTSC ; 33.35 mm/s (SP), 16.68 mm/s (LP·PB only), 11.12 mm/s (EP)
Recording/Playback Time: SP ; Max. 240 min (with E-240)
LP ; Max. 480 min (with E-240, PAL only)
EP ; Max. 480 min (with T-160, NTSC only)
Note: The antenna must correspond to the new standard DIN 45325 (IEC 169-2) for combined UHF antenna with
75 ohm connector.
Specifications are subject to change without prior notice.

4
VT-G14
VT-G21
IMPORTANT SERVICE NOTES
Maintenance and repair of this receiver should be done by qualified service
personnel only.
SERVICING OF HIGH VOLTAGE SYSTEM AND
PICTURE TUBE
When servicing the high voltage system, remove static charge from it by
connecting a 10k ohm Resistor in series with an insulated wire (such as a
test probe) between picture tube dag and 2nd anode lead. (AC line cord should
be disconnected from AC outlet.)
1. Picture tube in this receiver employs integral implosion protection.
2. Replace with tube of the same type number for continued safety.
3. Do not lift picture tube by the neck.
4. Handle the picture tube only when wearing shatterproof goggles and after discharging
the high voltage completely.
X-RAY
This receiver is designed so that any X-Ray radiation is kept to an absolute
minimum. Since certain malfunctions or servicing may produce potentially
hazardous radiation with prolonged exposure at close range, the following
precautions should be observed:
1. VT-G14: When repairing the circuit, be sure not to increase the high voltage to more
than 25.3 kV, (at beam 0 µA) for the set.
VT-G21: When repairing the circuit, be sure not to increase the high voltage to more
than 29.3 kV, (at beam 0 µA) for the set.
2. VT-G14: To keep the set in a normal operation, be sure to make it function on 22.0 kV +
1.5 kV – 2.0 kV (at beam 800 µA) in the case of the set. The set has been factory
– Adjusted to the above-mentioned high voltage.
VT-G21: To keep the set in a normal operation, be sure to make it function on 25.0 kV ±
1.5 kV (at beam 1100 µA) in the case of the set. The set has been factory –
Adjusted to the above-mentioned high voltage.
∴ If there is a possibility that the high voltage fluctuates as a result of the repairs, never
forget to check for such high voltage after the work.
3. Do not substitute a picture tube with unauthorized types and/or brands which may cause
excess X-ray radiation.
BEFORE RETURNING THE RECEIVER
Before returning the receiver to the user, perform the following safety checks.
1. Inspect all lead dress to make certain that leads are not pinched or that hardware is not
lodged between the chassis and other metal parts in the receiver.
2. Inspect all protective devices such as non-metallic control knobs, insulating fishpapers,
cabinet backs, adjustment and compartment covers or shields, isolation resistor-capac-
ity networks, mechanical insulators etc.

5
VT-G14
VT-G21
LOCATION OF USER'S CONTROL
Front
AV-1
IN
OUT
VIDEO AUDIO
AV-1
IN
OUT
VIDEO AUDIO
Thisservice manualis forVT-G14 andVT-G21.The
illustration of VT-G21 are used in this service
manual.
Rear
VIDEO
OUTPUT ANTENNA IN
terminal
AUDIO
INPUT
AUDIO
OUTPUT
VIDEO
INPUT
HEADPHONE jack
(Speaker audio turns off when connected
to a pair of headphones)
POWER button
VIDEO/AUDIO INPUT terminals
STOP/EJECT button
FF (Forward Video
Search) button
PLAY button
REW (Reverse Video
Search) button
PRESET button
CHANNEL UP/DOWN buttons
VOLUME UP/DOWN buttons
SHARP SUPER PICTURE button (This function will create a clearer image during playback.)
REC (Recording) button
REC indicator
PROGRAM TIMER indicator
CHILD-LOCK indicator
POWER/WAKE-UP TIMER indicator
Infrared sensor
window
STANDBY/ON
button

6
VT-G14
VT-G21
LOCATION OF USER'S CONTROL (Continued)
TV/VIDEO
CH
PLAY
STOP
REW
REC PAUSE
DPSS
PROG
MENU
TV
•
VCR COMBINATION
SET RETURNCONFIRM
FF
TR
123
456
78
0
9
COUNTER
RESET TAPE SPEED
TIMER
ON/OFF
RETURN button
CONFIRM button
• Used to confirm the
programme setting.
REW button
• Used to rewind the tape or to
conduct Reverse Video Search
during playback mode.
Remote Control
REC button
• Used to record a programme.
STANDBY/ON button
CHANNEL SELECT buttons
FLASHBACK button
Returns to previously
viewed channel.
TAPE SPEED button
• Used to select the recording
tape speed.
PLAY button
• Used for tape playback.
• Used to cancel the PAUSE/
STILL mode and return to nor-
mal playback operation.
SET button
TV/VIDEO Select button
Infrared Transmitter Window
MUTE button
Press →Mutes sound.
Press again →Restores
sound to previous level.
VOLUME UP/DOWN buttons
CHANNEL UP/DOWN
buttons (TRACKING ±/—)
• Used to select the
CHANNEL.
• Used to adjust the TRACK-
ING while playing the tape.
COUNTER RESET button
• Used to reset the tape
counter.
CHILD-PROOF LOCK button
• Used to lock any selected
mode.
FF button
• Usedtofast forwardthetape
ortoconductForwardVideo
Search during playback
mode.
STOP button
• Used to stop the tape.
PAUSE button
• Used to temporarily stop the
tapeduringrecordingmode.
• Used to display a still
picture during playback
mode.
DPSS buttons
• Press the ( /) button to
search for the index signal
and begin playback auto-
matically.
PROGRAMME button
• Press the button to set the
programme Timer.
MENU button
• Used to select the menu
screen.
Inserting batteries
Pull up
±, —buttons
TIMER ON/OFF button
Installing dry batteries in the remote control unit
Before using the TV set for the first time, install the supplied dry batteries in the remote control.
!With your thumb nail, pull up the slit as indicated by the arrow
to remove the back cover.
@Insert two batteries (size “AA”). Be sure to match the battery
±/—terminals with the ±/—marks inside the compartment.
#Replace the battery cover.
• Remove batteries if weak or if the unit is not in use for long periods.
• Do not mix old and new batteries.
• Incorrect installation of the batteries may damage the remote control.
DISPLAY button
• Usedtodisplaythedifferent
current settings on the
screen.

7
VT-G14
VT-G21
DISASSEMBLY AND REASSEMBLY
1. Remove the 10 rear cover fixing screws and detach the rear cover.
2. Take out the anode cap, CRT PWB, connectors F, G and AO, coating ground, SP chip, fixing screws and others.
3. Remove the 2(VT-G14)/1(VT-G21) Main PWB fixing screws and take out the Main PWB unit and the Power PWB.
4. Remove the 4 Power PWB fixing screws, and take out the Power PWB unit.
G
3
F
AO
2
(VT-G14 only)
4
1
1
VT-G21
VT-G14

8
VT-G14
VT-G21
DISASSEMBLY AND REASSEMBLY (Continued)
5. Remove the 7 VCR fixing screws, and detach the shielding case.
6. Remove the 4 cassette housing control fixing screws, and detach the cassette housing control.
7. Remove the 4 mechanism chassis fixing screws, and detach the mechanism chassis from the Main PWB.
8. Remove the 3 Main PWB fixing screws, and detach the Main PWB.
9. Remove the 4 Tuner/Def and IF PWB fixing screws, and detach the Tuner/Def and IF PWB.
5
6
7
7
7
8
9

9
VT-G14
VT-G21
DISASSEMBLY AND REASSEMBLY (Continued)
For servicing any of the components inside, disconnect the lead dressing holder. Position the main PWB unit upright
as shown below and connect the leads for starting the services.
70~80°
Note: Fit the VCR unit the front cabinet with the front flap door tilted at 70~80°.
K
FRONT
F
G
B
B
AJ AJ AV
AM
AN
PA
PA
PB
PB
SP
AN
AM
AV
H
AO
AO
K
H

10
VT-G14
VT-G21
ADJUSTMENT OF THE TV ELECTRICAL CIRCUITRY
ADJUSTMENT PRECAUTIONS
1. Calling the service mode
Get the service test points (TP1002 and TP1003) of the set short-circuited.
2. Getting out of the service mode
Get the above service test points open.
3. On-screen display in the service mode
A service mode item and its data appear in two lines
at the lower left on the screen.
Top line : Service mode item (See below)
Bottom line : Data (See below)
Service mode
Item Display Data Variable range
DIRECT MODE DIRCT Adjustable in the DIRECT MODE
V-AMPLITUDE V-AMP 0 ~ 127 R CUT OFF (0 ~ 255)
V-LINEARITY V-LIN 0 ~ 31 G CUT OFF (0 ~ 255)
V-OUT PHASE V-POS 0 ~ 7 B CUT OFF (0 ~ 255)
H-POSITION H-POS 0 ~ 31 G DRIVE GAIN (0 ~ 255)
BELL FILTER BELL 0 ~ 3 B DRIVE GAIN (0 ~ 255)
R-Y BLACK OFFSET R-Y 0 ~ 15
B-Y BLACK OFFSET B-Y 0 ~ 15
Y-SUB CONTRAST CONT 0 ~ 31
SUB COLOUR COLOR 0 ~ 240
SUB BRIGHT BRI 0 ~ 150
SUB TINT TINT 0 ~ 37
`NICAM D/K N-D/K 0 ~ 1
`IF INT/EXT IF-IN 0 ~ 1
`AGC GAIN AGCGA 0 ~ 31
`AGC OFF AGCOF 0 ~ 1
`FM SOUND ID FMID 0 ~ 3
`AUTO MUTE AMUTE 0 ~ 1
`NICAM LOW ERROR LIMIT NERRL 0 ~ 255
`NICAM UP ERROR LIMIT NERRU 0 ~ 255
`NICAM OUT LEVEL B/G B/G 0 ~ 31
`NICAM OUT LEVEL I I 0 ~ 31
`NICAM OUT LEVEL D/K D/K 0 ~ 31
`NICAM OUT LEVEL M M 0 ~ 31
`FM OUTPUT LEVEL FM 0 ~ 31
Note :
1) Item selectable by the CH '" buttons and data by the VOL '" buttons (effective on both
the remote controller and the set)
2) `This item is not used with the VT-G14 and VT-G21 (but displayed on the screen).

11
VT-G14
VT-G21
Item-by-item control in the service mode
1. DIRECT mode F-B/W 0 - > 1 (forced B/W)
2. DIRECT mode + HOR. POS. mode DRV CNT 0 - > 1 (drive forced center)
SUB-BRIGHT Initial value
R.G.B. CUTOFF 0 (E2PROM data resumed when any of the “0” thru
“9” buttons on the remote controller is pressed)
3. R-Y Black Offset CONTRAST MAX (USER-CONTROL)
BRIGHT MAX (USER-CONTROL)
COLOUR CENTER (USER-CONTROL)
R-MONITOR SW 0 - > 1 (MONITOR OUT)
MUTE MODE Y-MUTE
4. B-Y Black Offset CONTRAST MAX (USER-CONTROL)
BRIGHT MAX (USER-CONTROL)
COLOUR CENTER (USER-CONTROL)
B-MONITOR SW 0 - > 1 (MONITOR OUT)
MUTE MODE Y-MUTE
5. SUB Tint MUTE MODE Y-MUTE
6. Unspecified items PICTURE NORMAL (CONT. BRI. COL.)
Note :
All the settings will be back to the initial ones when shifting into any other mode or getting out of the
service mode.
Allocation of special buttons in the service mode
`HORIZONTAL POSITION CONFIRM (SET -> S-PICTURE)
`Y-MUTE SET
`COLOUR MAX./MIN. select TIMER ON/OFF
`DIRECT TUNING MODE RETURN
`VCR SLOW TEST PROG
`NVM MODE DISPLAY
Adjustment precautions
1) Basically follow the sequential order of adjustments.
(Unless otherwise specified, follow the adjustment procedures.)
2) The “`”-marked steps in the adjustment procedures are automatically taken when in the service mode. Leave
out these steps.
3) For adjustments in the service mode, it is necessary to have the remote controller at hand.
The numeric keys on the remote controller work as follows in the DIRECT mode only.
UP DOWN
R CUT OFF 1 4
G CUT OFF 2 5
B CUT OFF 3 6
G DRIVE GAIN 7
õ
Õ
B DRIVE GAIN 8 0
Notes :
In all the other modes, these buttons are used to select channels.
In the DIRECT TUNING mode, these buttons are used to enter data.

12
VT-G14
VT-G21
Initial settings of EEPROM data
Initial settings of adjustment items
Item Variable range Initial setting
R CUT OFF 0 ~ 255 0
G CUT OFF 0 ~ 255 0
B CUT OFF 0 ~ 255 0
V-AMPLITUDE 50Hz 0 ~ 127 35
V-AMPLITUDE 60Hz 0 ~ 127 37
V-LINEARITY 50Hz 0 ~ 31 25
V-LINEARITY 60Hz 0 ~ 31 18
V-OUT PHASE 50Hz 0 ~ 7 06
V-OUT PHASE 60Hz 0 ~ 7 03
HORIZONTAL POSITION 50Hz 0 ~ 31 08
HORIZONTAL POSITION 60HZ 0 ~ 31 12
Y-SUB CONTRAST 0 ~ 31 0
SUB-COLOUR 0 ~ 240 91
SUB-BRIGHT 0 ~ 150 100
G-DRIVE GAIN 0 ~ 255 128
B-DRIVE GAIN 0 ~ 255 128
SUB-TINT 0 ~ 37 18
BELL FO 0 ~ 3 01
R-Y BLACK OFFSET 0 ~ 15 8
B-Y BLACK OFFSET 0 ~ 15 8
PICTURE Adjust User setting
Initial setting : NORMAL (CONTRAST at MAX, others at CENTER)
Trouble indicators
If the set is interrupted by the protectors, the following indicators work to identify a spot in trouble.
1) LED (red) flashing : Deflection system protector activated (high-voltage or beam protector)
2) REC LED flashing : I2C bus line error (VCJ or tuner, EEPROM)
3) LED off : Power protector activated (+B line short-circuited)
Model
number In-house
product code
Sound
system
On-screen
display
language
Geomagnetism adjustment
VH
Background
y
x
45,000nT(0.45G)Russian
D/K
A3HEG14VJVT-G14 20,000nT(0.20G) 7,500°K 0.300 0.310
VT-G21 A3HEG21VJ D/K Russian 45,000nT(0.45G) 20,000nT(0.20G) 7500K 0.300 0.310
Factory settings

13
VT-G14
VT-G21
SERVICE ADJUSTMENT
ËË
ËË
ËPIF/AFT/AGC ADJUSTMENT
1. TUNER IFT : TU201 (preset)
1. Get the tuner ready to receive the E-9CH signal,
but with no signal input. Adjust the PLL data.
2. Connect the sweep generator’s output cable to
the tuner antenna. (RF sweep)
3. Adjust the sweep generator’s output level to 80
dBµV.
4. Connecttheresponselead(usealow-impedance
probe with wave detector; see
Fig.1 ) to the tun-
er’s IF output terminal.
(This terminal must have the probe alone con-
nected.)
5. Set the RF AGC voltage to 0V ~ 6V with no con-
tact with the waveform.
6. Adjust the tuner IF coil to obtain the waveform as
shown in
Fig. 2 .
Note : Be sure to keep the tuner cover in posi-
tion during this adjustment.
Fig. 1
IF-OUT
1000p 10kΩ
75Ω1000p 100kΩ
Oscilloscope
E-9CH
PC
–1.5dB
Fig. 2
1. VCO coil (T253)
1) Disconnecttheantennafromthe tunerantenna
terminal.
2) Apply DC voltage to pin (4) (IF AGC, TP252)
of IC251.
»DC voltage: 6.0 ± 0.1 V
3) Usingadigitalvoltmeter,measuretheDCvolt-
age at pin (20) (PLL FIL, TP253) of IC201.
»(The digital voltmeter must be able to take
readings down to the third decimal place.)
10 kHz at 0.007 V
4) Relieve TP252 of the DC voltage.
5) Reconnecttheantennainpositionandreceive
the E-12CH signal.
»(With the AFT off, adjust the receiving fre-
quency to 224.25 MHz.)
6) Connect the DC digital voltmeter to TP253.
Adjust T253 so that the voltmeter should read
the same voltage as in Step 3).
»Allowable error: 0.015 V (20 kHz)
2. AFT coil (T254)
1) ReceivetheE-12CH signal in the same condi-
tion as in Step 5) above.
2) Connect the oscilloscope to pin (1) (AFT,
TP251) of IC251.
3) Adjust T254 so that the DC voltage reading be
3.3 V.
»3.3 ± 0.1 V (from the 0-6.6 V variable range)
2. VCO and AFT ADJUSTMENT : T253 (VCO), T254 (AFT)
6V
3.3V
DOWN A B' B B" C UP
DC voltage at TP251
Fig. 3

14
VT-G14
VT-G21
Bias box:About 6.5V
ËË
ËË
ËPIF/AFT/AGC ADJUSTMENT(Continued)
3. RF AGC CUT-IN ADJUSTMENT: R265
1. Receive the “E-12CH”(PAL COLOUR BAR) sig-
nal.
»Field strength: 57 ± 1 dBµV (75 ohms open)
2. Connect the oscilloscope to TP201, as shown at
right.
3. Turn R265 to have the highest voltage.
4. Turn R265 slowly in the opposite direction until
the voltage goes down 0.1 V below the highest
level.
5. Adjust the signal level to 63 ~ 67 dBµV and make
sure there is no noise.
6. Now adjust the signal level to 90 ~ 95 dBµV and
make sure there is no chrominance modulation
beat.
Note : If a 50 ohm field strength meter is used
without a 50/75 impedance converter, set
the field strength to 55 ±1 dBµV. Pay atten-
tion to a loss that would be caused with
the converter.
Oscilloscope
0.1V
TV Set
Bias box
TP201+
+
–
–
Fig. 4

15
VT-G14
VT-G21
ab
Left Right
Beam landing equally outwards.
Left Right
Beam landing shifted to right.
Left Right
Beam landing shifted to the left.
ËË
ËË
ËPURITY ADJUSTMENT
1. PURITY ADJUSTMENT
1. First of all, let a beam current of over 700µA flow
in the set to warm it up for 30 minutes or longer.
(over 400 µA for VT-G14).
2. Keep the purity magnet in the zero magnetic field
in advance. Roughly adjust the static conver-
gence.
3. Receive the green-only colour signal. Adjust the
beam current to about 770 µA. (about 500 µA for
VT-G14)
4. Degauss the cathode ray tube enough with the
degaussing coil.
ADJUSTMENT
Eastward magnetic field specified
1) Observe the beam landings “a”and “b”, as
shown in Fig. A , through a microscope. Ad-
just the landings as specified.
2) If the right and left landings are equally out-
ward as shown in Fig. B , move the deflection
yoke forward.
3) If the right or left landing is shifted to the right
or to the left, as shown in Fig. C and Fig. D ,
adjust the opening angle of the purity magnet.
4) Makesuretherightandleftbeamlandingsare
justasspecified about the screen center. Now
check the cathode ray tube corners.
Be sure that all the landings are at rank “B”.
5) If any other colour appears on the screen,
move the deflection yoke back and forth.
LANDING ERROR
»Outward: Move the deflection yoke forward.
»Inward:Movethedeflectionyoke backward.
6) Receive the monoscope pattern signal.
RASTER ROTATION
7) Adjust the raster rotation to “0”eastward.
»Adjustment error : 0 ±2 mm
8) Tighten up the deflection coil screws.
»Tightening torque : 11±2 kg
Note : Each time the single-colour button is
pressed, the screen colour changes as
follows.
Fig. A
Fig. B
Fig. C
Fig. D
Green-only
screen Red-only
screen
Single-colour
screen cleared
Blue-only
screen

16
VT-G14
VT-G21
ËË
ËË
ËCONVERGENCE ADJUSTMENT
1.CONVERGENCE ADJUSTMENT
(to be done after the purity adjustment)
Wedge "a"
Lacquer
Wedge "b" Wedge "c"
Approx.100°Approx.100°
4-pole magnet
6-pole magnet
CRT neck
Lacquer
Purity magnet
1. Receive the crosshatch pattern signal.
2. Usingtheremotecontroller, call the Normalmode.
STATIC CONVERGENCE
1. Turn the 4-pole magnet to a proper opening an-
gle in order to superimpose the blue and red col-
ours.
2. Turn the 6-pole magnet to a proper opening an-
gle in order to superimpose the green colour over
the blue and red colours.
DYNAMIC CONVERGENCE
1. Adjust the convergence on the fringes of the
screen in the following steps.
»Fig. a :Drive the wedge at point “a” and
swing the deflection coil upward.
»Fig. b :Drive the wedges at points “b” and
“c” and swing the deflection coil
downward.
»Fig. c :Drive the “c” wedge deeper and
swing the deflection coil rightward.
»Fig. d :Drive the “d” wedge deeper and
swing the deflection coil leftward.
2. Fix all the wedges on the cathode ray tube and
apply glass tape over them.
3. Apply lacquer to the deflection yoke lock screw,
magnet unit (purity, 4-pole and 6-pole magnets),
and magnet unit lock screw.
Finally receive the red-only and blue-only colour sig-
nals and make sure there is no other colour mixed
on the screen.
Fig. a Fig. b
Fig. c Fig. d
Fig. 5
B G R
B
G
R
R G B B
G
R
R G B
R
G
B
B G R R
G
B

17
VT-G14
VT-G21
ËË
ËË
ËCRT CUT-OFF, BACKGROUND AND SUB-CONTRAST ADJUSTMENT (1)
1.CRT CUT-OFF (I2C bus data adjustment)
1. Receive the monoscope pattern signal.
2. Put the set in the service mode and call up the DIRECT mode (DIRCT).
3. Set the screen control to 0/10 position.
4. Press the “CONFIRM”button on the remote controller to reach the horizontal centering mode. (S-PICTURE
button on the set)
5. Turn the screen control clockwise until the horizontal raster of the first glimmering colour becomes slightly
visible.
6. Adjust the cut-off data of the other two colours until the horizontal raster becomes whitish.
Note : The data can be turned up and down with the above buttons.
»R CUT OFF UP “1”BUTTON »G CUT OFF DOWN “5”BUTTON
»R CUT OFF DOWN “4”BUTTON »B CUT OFF UP “3”BUTTON
»G CUT OFF UP “2”BUTTON »B CUT OFF DOWN “6”BUTTON
7. Turn the screen control counterclockwise until the horizontal raster disappears.
Note : Before starting this adjustment, warm up the unit for 30 minutes or longer at a beam current of over
700 µA (over 600 µA for VT-G14).
8. Press the “CONFIRM”button on the remote controller to call up the NORMAL mode. (S-PICTURE button on the
set)
SUB-BRIGHTNESS (I2C bus data adjustment)
9. Using the remote controller, call the SUB-BRIGHT setting mode (BRI). (Receive the crosshatch and gray scale
signal.)
10.Set the sub-brightness data so that the third black portion (1st to 5th counted from the left of the screen) of the
window pattern looks sinking.
Note : The service mode adjustment in the above steps 9. and 10. should be carried out after the white
balance and background adjustments.
11.Exit from the service mode.
2. WHITE BALANCE AND BACKGROUND (I2C bus data adjustment)
1. Receive the monoscope pattern signal.
2. Put the set in the service mode and call up the DIRECT mode (DIRCT).
3. Connect the beam ammeter between TP601 and TP602.
4. Using the sub-contrast control, roughly adjust the beam current to about 1,000 µA (about 700 µA for VT-G14).
5. Adjust the G-drive and B-drive data to have a colour temperature of 7,500°K (white).
»7,500°K x : 0.300
y : 0.310
(with a Minolta colour temperature meter CA-100)
Note : The data can be turned up and down with the above buttons.
»G-DRIVE UP “7”BUTTON »B-DRIVE UP “8”BUTTON
»G-DRIVE DOWN “
õ
Õ
”BUTTON »B-DRIVE DOWN “0”BUTTON
6. Adjust the contrast and brightness controls to have the beam current of 200 µA or so. Now check the back-
ground colour. If the colour temperature is not as specified, go back to No. 1 on the preceding page.
7. Exit from the service mode.
Note : Before starting this adjustment, warm up the unit for 30 minutes or longer at a beam current of over
700 µA (over 600 µA for VT-G14).

18
VT-G14
VT-G21
ËË
ËË
ËCRT CUT-OFF, BACKGROUND AND SUB-CONTRAST ADJUSTMENT (2)
3. SUB-CONTRAST
(I2C bus data adjustment)
1. Receive the crosshatch pattern signal.
2. Put the set in the service mode and select the SUB-CONTRAST mode (CONT).
3. Adjust the sub-contrast data to "10" (VT-G21)/ "0" (VT-G14).
4. Exit from the service mode.
Note :
The selected channels in parentheses have the
following signals.
Monoscope pattern (50 Hz) signal
Fig.6
AB
ËË
ËË
ËHORIZONTAL AND VERTICAL CIRCUIT ADJUSTMENT
1. SERVICE MODE DATA ADJUSTMENT
Put the set in the service mode.
Turn up or down the data for this adjustment.
I2C bus data adjustment
»V-AMP 50 Hz
A) Select the V-AMP mode (V-AMP). Adjust the
overscan to 10% .
»V-LINEARITY 50 Hz
B) Select the V-LIN mode (V-LIN). Adjust to get the
best linearity.
»V-OUT PHASE 50 Hz (V-CENTER)
C) Select the V-OUT POS mode (V-POS). Align the
screen center with the cathode ray tube’s geo-
metrical center.
»H-POS 50 Hz (H-CENTER)
D) Select the H-POS mode (H-POS). Make the dis-
tances “A”and “B”on both sides equal.
Exit from the service mode.
Adjust point
Fig.7
2. FOCUS ADJUSTMENT
1. Receive the monoscope pattern signal.
2. MakethePICTUREADJUSTsettingtoNORMAL.
3. Adjust the focus control so that the middle areas
betweenthepattern’scenterand thescreen’s both
ends be in the best focus.
For the V-AMP 60 Hz, V-LINEARITY 60 Hz, V-OUT PHASE 60 Hz, and H-POS 60 Hz adjustments, their corrected
data are automatically entered when the corresponding 50 Hz mode adjustments are made. Check these data on
the 60 Hz mode screen. Readjust any of them if required. (The 50 Hz and 60 Hz modes are selected on the
screen.)
Once the adjustment has been made in the 60 Hz mode, do not change it in the 50 Hz mode.

19
VT-G14
VT-G21
ËË
ËË
ËPAL CHROMA ADJUSTMENT
1. SUB-COLOUR ADJUSTMENT (I2C bus data adjustment)
1. Receive the PAL colour bar signal.
2. Put the set in the service mode.
3. Select the sub-colour mode (COL).
4. ConnecttheoscilloscopetoTP855(REDcathode).
(Use a 10 : 1 probe.) (TP852 for VT-G14)
»Range: 20 V/div.
»Sweep time: 20 µsec/div.
5. Adjust the sub-colour data so that the 75% white
and red portions of the PAL colour bar be at the
same level. See Fig. 8 .
6. Exit from the service mode.
»When getting out of the SUB-COLOUR mode,
the sub-colour data turns up 15.
WYCYG
MG
RB
To be at the same level
Fig.8
ËË
ËË
ËSECAM CHROMA ADJUSTMENT
1. BELL FILTER (ƒ0) (I2C bus data adjustment ) (adjustment not required)
1. Receive the SECAM colour bar signal.
2. Put the set in the service mode.
3. Select the BELL FILTER (f0) mode (BELL).
4. Adjust the data to 1.
5. Exit from the service mode.
WY
CY G
MG
RB
About 3 Vp-p
Fig.9
ËË
ËË
ËNTSC CHROMA ADJUSTMENT
1. SUB-TINT ADJUSTMENT (I2C bus data adjustment)
1. Receive the NTSC colour bar signal.
2. Put the set in the service mode.
3. Select the SUB-TINT mode (TINT).
4. Connect the oscilloscope to TP802 (B-Y OUT).
»Range : 10 mV/div. (AC)
»Sweep time :10 µsec/div.
(Use a 10 : 1 probe.)
5. Adjust the sub-tint data to obtain the waveform
as shown in Fig. 9 .
6. Exit from the service mode.

20
VT-G14
VT-G21
ËË
ËË
ËSECAM CHROMA ADJUSTMENT(Continued)
2. SECAM BLACK LEVEL (R-Y/B-Y) and BLACK OFFSET ADJUSTMENT
(I2C bus data adjustment)
1. Receive the SECAM colour bar signal.
2. Call the service mode.
3. Select the R-Y black offset mode (R-Y).
4. Connect the oscilloscope to pin (36) (B-Y OUT,
TP802) of IC801.
»Range : 10 mV/div.
»Sweep time :5 µsec/div. (Use a 10 : 1 probe.)
5. Vary thedatasothatthebackporchandthewhite
level should become at the same level. See Fig.
10 .
6. Select the B-Y black offset mode (B-Y).
7. Reconnect the oscilloscope to pin (35) (B-Y OUT,
TP801) of IC801. Keep the same conditions as in
Step 4. above.
8. Vary thedatasothatthebackporchandthewhite
level should become at the same level. See Fig.
11 .
9. Quit the service mode.
10.Finally adjust the colour control to the MAX and
MIN positions to make sure there is no change in
the background.
Fig.10
Fig.11
YWCY
To be at the same level
Back porch
YWCY
YWCY
To be at the same level
Back porch