Tauras TV2K-TXT User manual

TV2K - TXT
COLOUR TELEVISION RECEIVER
SERVICE MANUAL
SECIFICATION
zSYSTEM PAL/SECAM,B/G,DK, I.
zPOWER INPUT AC 170-245V(50/60Hz)
zPOWER CONSUMPTION 60W
zAERIAL IMPEDANCE 75OHM UNVALANCED
zTUNER VOLTAGE SYNTHESIZER TUNING
zRECEIVING CHANNELS VHF-L E2-S6
VHF-H S7-S41
UHF E21-E69

zPROGRAMME MAX.99 PROGRAM MEMORIES
zPICTURE TUBE 14”,20”,21”;90°
zSOUND OUTPUT 2.0W
zSPEAKER 3W 8 OHM
zAV JACKS FULL SCART ×1
CAUTION : Before servicing the chassis, read the “Safely Precaution”.
“X -Ray radiation Precaution” and “Product Safety Notice” in this manual.
X-RAY RADIATION PRECAUTION
1. Excessive high voltage can produce potentially hazardous X-RAY RADIATION. To
Avoid such hazards the high voltage must be specified limit. The normal value of the
high voltage of this receiver is 24.5KV +/-2KV under 230V AC power source. The
high voltage must not exceed 27KV.

2. Each time a receiver requires servicing the high voltage should be checked following
the HIGH VOLTAGE CHECK procedure in this manual. It is recommended the
reading of the high voltage be recorded as a part of the service record. It is
important to use an accurate and reliable high voltage meter.
3. The primary source of X -RAY RADIATION in this TV receiver is the picture tube.
For continued X-RAY RADIATION protection, the replacement tube must be exactly
the same type tube as used in this TV receiver.
4. Some parts in this receiver have special safety-related characteristics for X-RAY
RADIATION protection. For continued safety, parts replacement should be
undertaken only after referring the PRODUCT SAFETY NOTICE below.
SAFETY PRECAUTION
WARNING: Service should not be attempted by anyone unfamiliar with the necessary
Precautions on this receiver.
The following are the necessary precautions to be observed before servicing this
chassis.
1. Since the power supply circuit of this receiver is directly connected to the AC
power line. An isolation transformer should be used during any dynamic service to
avoid possible shock hazard.
2. Always discharge the picture tube anode to the CRT conductive coating before
handling the picture tube. The picture tube is highly evacuated and if broken, glass

fragments will be violently expelled. Use shatterproof goggles and keep picture tube
away from the unprotected body while handling.
3. When replacing a chassis in the cabinet, always be certain that all the protective
devices are put back in place, such as: nonmetallic control; knobs, insulating covers,
shields, isolation resistor-capacitor, network, etc.
4. When replacing parts or circuit boards, disconnect the power cord.
5. When replacing a high voltage resistor (metal oxide resistor) on circuit hoard,
keep the resistor APP. 10mm(1/2 in.) away from circuit board.
6. Connection wires must be kept away from components with high voltage or high
temperature.
7. If any fuse in this TV receiver is blown, replace it with the FUSE specified in the
chassis parts list.
8. The receiver is designed to operate with 230V(50Hz) AC mains.
PRODUCT SAFERY NOTICE
Many electrical and mechanical parts in this chassis have special safety-related
characteristics are often passed unnoticed by a visual inspection and the X-RAY
RADIATON protection afforded by them cannot necessarily be obtained by using
replacement components rated for higher voltage. The use of substitute replacement
parts that do not have the same safety characteristics as specified in the parts list may

create shock, fire, X-RAY RADIATION or other hazards.
GENERAL ADJUSTMENT
AUTOMATIC DEGAUSSING
An automatic degaussing coil is attached around the picture tube, degaussing the tube
properly in about one second after the set is switched on. If the receiver is moved or
faced on a different direction, the power must be switched off at least 15 minutes in
order that the automatic degaussing circuit operated properly. External degaussing is
necessary if the automatic degassing proves ineffective after the set is moved.
B+ ADJUSTMENT
C AUTION: To avoid X-ray hazards and result in a nominal display width, B+ voltage
must be set in the scale of 108.0V+/-0.5V.
1. Make sure the AC power supply is 230V, 50Hz.
2. Switch on the TV receiver, tune in an active channel.
3. Measure the voltage between C641 on Main P.C. Board by DC voltmeter.
4. Set contrast, brightness, color to maximum.
5. Adjust VR631 on Main P. C. Board for B+108.0V+/-0.5V voltage reading.

HIGH VOLTAGE CHECK
C AUTION: There is no high voltage adjustment in this chassis, B+108V voltage
directly relates to the high voltage. The high voltage does not exceed 27KV under any
conditions.
1. Connect an accurate high voltage meter to the second anode cap of the picture
tube.
2. Turn on the receiver, set brightness and contrast to minimum (Zero beam
current).
3. Make sure the high voltage does not exceed 27KV.
4. NO matter whether the luminance, contrast and chrominance controls are set to
maximum or minimum, the high voltage must be kept under 27KV.
FOCUSING
Receive a TV test pattern signal; adjust controls for optimum picture. Adjust Focus
Control for a well-defined, sharpest display in the center area of the screen.

ADJUSTMENT AND SERVICING THE CHASSIS
SERVICE MODE
To enter the service mode, a special remote control which contains an additional
SERVICE key must be used. See the illustration. Press the ‘SERVICE’ key on
remote control, TV will display service menu as following table 1 line by line. To select
the parameter by using the ‘P+/P-’ keys. To adjust the selected parameter by using
the ‘V+/V-’ keys. To quit the service mode, press the ‘P.P.’ key on remote control
when in the service mode.
Table 1
Parameter Value 14 “ Value 20”,
21 “
Red Gain 32 40
DC Red 063 063
Green Gain 32 40
DC Green 063 063
Blue Gain 32 40
DC Blue 063 063
Apr Threshold 12 12
Logo 6------------ 6------------

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To enter the table 2, press the ‘OK’ key for
the first time on the remote control when in
the service mode.
Table 2
Parameter Value
Tuner AGC 22
H position 32
VPOS 50 10
VPOS 60 10
VAMP 50 47
VAMP 60 53
Bright max 63
Bright min 00
Sub Tint 32
VCO Coarse 05
VCO Fine 063
VCO Coarse L1 05
VCO Fine L1 080
To enter the table 3, press the ‘OK’ key for
the second time on the remote control
when in the service mode.
Table 3
Parameter Value
AGC gain 00
Option 1 48
Option 2 00
Option 3 06

Option 4 09
Option 5 00
ST Ttext 00
H POS OSD 001
V POS OSD 01
H POS TXT 066
V POS TXT 04
Following are the items of the OPTIONS in more details.
OPTION1:
B5=P/N/S Crystals application (0=2 crystals, 1=1 crystal)
B4=Cutoff Loop (0= OFF, 1=ON)
B3=Safety_Reset (0=Active, 1=non)
B2=Super Tuner (0=OFF, 1=ON)
B1=Sound Demodulation (0= Intercarrier/MONO, 1=QSS/NICAM)
B0=Logo Display (0=OFF, 1=ON)
OPTION2: (It’s better to keep the default setting option2=0)
B5=Half_Contrast (0=OFF, 1=ON)
B4=Color 6db (0=OFF, 1=ON)
B3=APR Feature (0=ON, 1=OFF)
B2=Black Stretch (0=ON, 1=OFF)
B1=Auto Flesh (0=ON, 1=OFF)
B0=Coring (0=ON, 1=OFF)
OPTION3:
B5=AVL (0=OFF, 1=ON)
B4=PIF Over modulation (0=OFF, 1=ON)

B3=Market_France-SECAM L/L’ (0=OFF, 1=ON)
B2=Manual/Auto Cutoff (0=Manual, 1=Auto Cutoff)
B1=Mute pin Low/High To control the speaker (0=Low, 1=High)
B0=TDA7449/TDA7439 (0=TDA7449, 1=TDA7439)
OPTION4:
B4=SCART2 (0=OFF, 1=ON)
B3=RGB (0=OFF, 1=ON)
B2=SVHS (0=OFF, 1=ON)
B1=AV2 (0=OFF, 1=ON)
B0=AV1 (0=OFF, 1=ON)
OPTION5 and ST Ttext is for teletext setting only. It normally could not be changed. If
it’s necessary to adjust the OPTION 5, please read the following information before
adjustment.
A. For CPUs with English, French, German, Polish or English, French, German, Turkish,
Please refer to the setting as below.
1. If OPTION 5 = 00, then the TEXT languages like "ENGLISH, FRENCH, SWEDISH,
TURKISH, GERMAN, PORTUGUESE, ITALIAN, RUMANIAN " can be decoded.
2. If OPTION 5 = 02, then the TEXT languages like "POLISH, FRENCH, ESTONIAN,
CZECH, GERMAN, SERBIAN, LETTISH, RUMANIAN " can be decoded.
3. If OPTION 5 = 04, then the TEXT languages like "ENGLISH, FRENCH, SWEDISH,
CZECH, GERMAN, PORTUGUESE, LETTISH, RUMANIAN " can be decoded.
4. If OPTION 5 = 06, then the TEXT languages ENGLISH, FRENCH, SWEDISH, TURKISH,
GERMAN, PORTUGUESE, LETTISH, RUMANIAN can be decoded.
B. For coming new OTP/CPU with English, Russian, Czech, Polish, the setting of the OPTION
5 will be changed as below.
1. If OPTION 5 = 00, then the TEXT languages like "ENGLISH, FRENCH, SWEDISH,
CZECH, GERMAN, PORTUGUESE, ITALIAN, RUMANIAN " can be decoded.
2. If OPTION 5 = 02, then the TEXT languages like "ENGLISH, RUSSIAN, SWEDISH,
TURKISH, GERMAN, PORTUGUESE, ITALIAN, RUMANIAN " can be decoded.
3. If OPTION 5 = 04, then the TEXT languages like "POLISH, RUSSIAN, SWEDISH,
CZECH, GERMAN, SERBIAN, ITALIAN, RUMANIAN " can be decoded.

4. If OPTION 5 = 06, then the TEXT languages like "POLISH, RUSSIAN, SWEDISH,
CZECH, GERMAN, PORTUGUESE, ITALIAN, RUMANIAN can be decoded.
Normally, it is supposed not to set OPTION 5 = 01. If you set the OPTION 5 = 01, then the font
can be switched by press key MENU on remote control in TEXT mode for TV3K. If you set
OPTION 5 = 00, 02, 04, 06, then there is no any activity while press MENU in TEXT mode.
Please check.
A.F.C. ADJUSTMENT
Removing any R.F. signal source and prevent any stray signal source from entering
the tuner by shorting the tuner input inner contact to the out screen.
Inject the 38.9 MHZ carrier into the tuner IF output pin (pin 11).Select the parameter
‘VCO Coarse’ in the service mode (see Table 2).The ‘VCO Status…’will appear on
the screen. Then press the ‘AV’ key on remote control, the CPU will adjust
automatically until the ‘VCO Status OK’ appears on the screen. If this can not be
achieved, i.e. there is no any pattern on the screen, please adjust the T201 first until a
stable pattern appears on the screen. And then press the ‘AV’ key on remote control.
The CPU will adjust automatically once again until the ‘VCO Status OK’ appears on
the screen.
GEOMETRY
To adjust the picture position and vertical size, select the appropriate parameter in the service
mode and adjust as necessary. Please see table 2.
Remote control
29 DIRECTIVTY 6m(MIN) 8m(NOR
)
OK
30 DIRECTIVTY 30°FROM LIGHT AXIS 5m(MIN) 7m(NOR OK

)

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USER MANUAL

- 3 -
Programmes’settingTV-2K
After first pressing After second pressing After third pressing
Picture Install Setup
Brightness Auto Tune Timer
Contrast ManualTune Organize
Colour FineTune Function
Sharpness Store Language
Press remote control key MENU. On TV screen appears tables MENU:
Press the MENU key on remote control 2 times and choose function “Install”. Press P- key and choose
“Auto Tune” or “Manual Tune” functions. Press the OK key to enter programs’ search mode. When
programmeappears,presstheMENUkeyandreturntotheinstallationtable.PrestheP-keyandchoose
function “Store”. Press the OK key. When installation table appears, choose required programme
number in table “Programe” by using “+”, “-” keys, then choose Store and OK.
Press the MENU key to return to the installation table and start setting of the next programme.
Controlofsupplyvoltages
Programme UEBL (PAL) must by turned on TV set
Parametername Parameter
value Controlelement Measuring place Measuring conditions
Supply voltage (106-114)V VR5O1 D6O7"+” UEBL
BRIGHT.SATURAT-31
CONTRAST-45
Filamentvoltage 6,O-6,6V VR5O1 Stand connector

- 4 -
4.1 Centering
-horizontal
-vertical
+6mm
+4mm Hposition VPOS5O O-63 O-15 UEBLPALGRID at 9 gradations
of brightness
4.2 Picture size
-horizontal
-vertical
22.5-24.5
windows’
16.5-18.0
windows
VR5O1
VAMP 5O
O-63
UEBL brightness
from min. to max.
4.3 Nonlinear
distortions along
horizontal and
vertical
See user
parameters’
checking
AS
GRIGat9
gradations of
brightness
Regulation and checking of raster parameters’ (TV-2K)
Parametername Parameter
value Controlelement Measuring place Measuring
conditions
4.4 Geometrical
distortions
The other parameters you should set as indicated in the table.
Service table 1 Service table 2 Service table 3
Service modes
14" 20",21" Service V3.0 14"TV 20",21"TV Design
Red Gain 32 40 Tuner AGC 22 22 AGC Gane 00
DC Red 064 064 *HPosition 31 31 Option 1 48
Green Gain 32 40 *V Pos 50 10 07 Option 2 00
DC Green 063 063 -V Pos 60 11 11 Option 3 07
Blue Gain 32 40 *V AMP 50 44 55 * Option 4 09 (11)
DC Blue 063 063 -V AMP 60 62 62 Option 5 00
Apr. Threshold 15 15 Bright Max. 63 63 ST Text 00
Logo 6— 6— BrightMin. 00 00 HPOSOSD001
Sub. Tint 32 32 V POS OSD 01
-VCO Coarse 05 05 HPOSTXT057
-VCO Fine 039 - 069 V POS TXT 04
-VCO Coarse L1 05 05 Op.4 *09-AV,RGB;
-VCO Fine L1 080 080 Op.4*11-AV1,AV2,RGB
Press the service key and the OK key on remote control one time. First service table appears on
the screen. You will have second service table Service V3.0 - after pressing the OK key the
second time and Design table - after pressing one more time. Set the raster parameters visually
by using the remote control keys “+”, “-”, “P+” and “P-”: size, centering, nonlinear and geometrical
distortions.

- 5 -
Specific value of V AMP 50 depends on type picture tube.
* The parameters values are specified during adjusting operations.
- Uncontrolled parameters
The values of parameters should be set as shown in table.
To exit from service mode you should press the service key.
Check value of high voltage. The voltage should be not less than 20.5 kV at maximal brightness
and contrast. The high voltage should not exceed 26.5 kV at 100 µA of current. When current
through picture tube changes from 900 µA to 100 µA, the change of high voltage should not
exceed 10 % and the size change of picture should not exceed 12 mm along the vertical and 16
mm along the horizontal. The current through the tube should be over the range 700 - 950 µA.
Switch on 0.5SJ+0.5JB signal. Evaluate visually the quality of SJ signal. The bars shoul be located
in this way: white, yellow, bluish, green, purple, red, blue, black. During change of brightness the
line of flyback should not appear.
Switch on TEXT signal. Evaluate visually the quality of the signal.
NOTE. During control youl sold pay attention if three main colours - red, blue and green - present
in teletext. Take technological remote control ir switch TV board to AV1 mode. (Red key).
Depending on trasmited signal, a programme should presen on monitor screen.
Check if sound passes to TV board through SCART connector in mode AV by regulating soun
from min to max.
Press the red key on remote control and switch the board to the television mode. Range of video
signal on SCART connector should be equal 1+0.1 V (complete range)when measuring by
osciloscope on adapter pins. The oscilloscope picture of sound shoud present on both adapter
pins.
Corection of field clarity and beam convergence are made after loosening of MSS fixig ring and by
rotation the rings of clear field and static convergence. The correction of dynamic convergence in
corners is made by inserting additional shunt under the beam deflection system. After finding of
correct position, the shunt should be glued to the cone of picture tube. Dynamic convergence
should be made at the repairee workplace.
Half of coloured, half of white and black bars - evaluation of sound and picture quality of english
stadard (I)
Press the TXT key on remote control. The teletext page with number 100 should appear on the
screen. Check it visually if there are no any picture defects on it. Pres the AUTOSTORE or AV key
on remote control. The page with number 101 should appear on the screen. Check it visually if
there are no any errors and picture defects on it.Switch off the teletext by presiing TXT key.
Checking of remote control keys and AV1-AV2-RGB modes (red key).
Pull out aeriak and check if the sound is blocked and the screen is blue. The pictute and sound
should be restored after connectin of the aerial. Assure that TV set does not radiate noises in
any mode.
Leave:BRIGHTNESS-31,CONTRAST-50,SATURATION-31,SOUND-0.
Field clarity. Beam convergence

- 6 -
Device “YPY”-10
WARNING! 1. All procedures with breakdown device must be executed witth dielectric
gloves and on dielectric mat.
2. The aerial with signals should be disconected.
3. The device shoul be surely earthed.
1. Stop the TV set front a mirror on conveyor.
A plug of TV power cable connect to the socket of electric resistance control device.
2. Connect a grounding plug of “aerial” type of device to the TV aerial socket.
3. Output wire should be connected to “=” marked terminal, the switch “=” of device output
voltage should be in position “=”.
4. Press the key of output voltage switch by left hand and keep it in this position.
5. Press the output voltage regulator and rotating it evenly increase the output voltage to 4240 V
gradually (in 3-10 seconds) controlling it by means of device instruments. Hold the 4240 V voltage
3 - 5 seconds and visually check the indications of instruments.
6. By evenly rotation of output voltage regulator, decrease the voltage to 0 V. Release the key of
output voltage switch.
7. Disconnect the grounding plug of “aerial” type of device from aerial input on TV.
CHECKINGOFELECRICRESISTANCE
Connect a generetor of 60 dB/µ 38.9 MHz to the pins 10 and 11 of selector. During this operation
pay attention that signal output must be connected to the pin 11, and the housing of cable - to pin
10. Switch on the service mode of TV set.
Bright line lower to record “VCO Fine 063”. Rotate a circuit L208 and wach if record “AFC Status
OK” appears. Press the “-” key on remote control and find the lower limit of intermediate
frequency (IF) range (the record OK ust disappear). After this by using the “+” key adjust ID by 5
digits from end og range. “VCO Coarse” should be equal 05. Disconect the IF cable from pins of
selector.
220OM
38.9 MHz >———————————————> 11
50-150 mV ———————————————> 10
unmodulated
Setting of intermediate frequency

- 7 -
La composizione dei programmi TV-2K
Avendo premuto il tasto “MENU” sul telecomando sullo schermo del televisore appaiono le tabelle
“MENU”:
Avendo premuto la prima volta Avendo premuto la seconda volta Avendo premuto la terza volta
Picture Install Setup
Brightness Auto Tune Timer
Contrast ManualTune Organize
Colour FineTune Function
Sharpness Store Language
Premere due volte il tasto del telecomando “MENU”e scegliere la funzione “Install”.
Premere il tasto “P-”e scegliere la funzione “Auto Tune”oppure “Manual Tune”.
Premere il tasto “OK”per inserire il modo di ricerca dei programmi.
Quandoappareilprogramma,premereiltasto“MENU”etornarealletabelledelleinstallazioni.Premere
il tasto “P-”e scegliere la funzione “Store”.
Premere il tasto “OK”. Quando appare la tabella delle installazioni “Programe”sulla riga, scegliere il
numero del programma desiderato con l’aiuto dei tasti “+”, “-”, scegliere “Store”e “OK”.
Premere il tasto “MENU”per tornare alla tabella delle installazioni e rincominciare la composizione del
prossimo programma.
Il controllo delle tensioni di alimentazione
Nel TV deve essere inserito il programma UEBL (PAL)
La denominazione
del parametro Il valore del parametro L’elementodi regolazione Il luogo di misura Le condizioni di misura
La tensione di
alimentazione (106-114)V VR5O1 D6O7"+”UEBL
La luminanza -31
Il contrasto -45
La tensione di
riscaldamento 6,O-6,6V VR5O1 Ilcolleganmento del banco