19A30
Capítulo 1: Ajustes generales
Instrucciones de seguridad
Ajuste inicial
Modo de servicio
Modo de diseño
Ajustes eléctricos
Revisiones de circuitos
Capítulo 2: Informaciones específicas
Fijación y ajuste de los datos
Localización de controles
Programando la memoria de canal
Diagrama a bloques del circuito
Lista de partes de reempalzo del chasis y el gabinete
Vista inferior de las placas de circuito impreso
Vista de terminales de transistores
Especificaciones
Apéndice: Diagrama del circuito
Televisores a color
TOSHIBA CORPORATION
1-1, SHIBAURA 1- CHOME, MINATO-KU, TOKYO 105-8001, JAPAN
FILE NO. 020-200002
SERVICE MANUAL
COLOR TELEVISION
N0ES Chassis
19A30, 19A10
(TAC0007)
(TAC0005)
PRINTED IN U.S.A.
Feb., 2000
U
2
GENERAL
ADJUSTMENTS
SPECIFIC
INFORMATIONS
TABLE OF CONTENTS
CHAPTER 1 GENERAL ADJUSTMENTS
SAFETY INSTRUCTIONS ........................................................................................................................................ 3
SET-UP ADJUSTMENT ............................................................................................................................................ 4
SERVICE MODE ...................................................................................................................................................... 8
DESIGN MODE ...................................................................................................................................................... 11
ELECTRICAL ADJUSTMENTS .............................................................................................................................. 12
CIRCUIT CHECKS ................................................................................................................................................. 16
CHAPTER 2 SPECIFIC INFORMATIONS
SETTING & ADJUSTING DATA ............................................................................................................................. 17
LOCATION OF CONTROLS ................................................................................................................................... 18
PROGRAMMING CHANNEL MEMORY ................................................................................................................. 19
CIRCUIT BLOCK DIAGRAM .................................................................................................................................. 20
CHASSIS AND CABINET REPLACEMENT PARTS LIST ......................................................................................21
PC BOARDS BOTTOM VIEW ................................................................................................................................ 27
TERMINAL VIEW OF TRANSISTORS ................................................................................................................... 30
SPECIFICATIONS .................................................................................................................................................. 33
APPENDIX:
CIRCUIT DIAGRAM
3
GENERAL
ADJUSTMENTS
SPECIFIC
INFORMATIONS
CHAPTER 1 GENERAL ADJUSTMENTS
SAFETY INSTRUCTIONS
WARNING: BEFORE SERVICING THIS CHASSIS, READ THE "X-RAY RADIATION PRECAUTION", "SAFETY PRECAU-
TION" AND "PRODUCT SAFETY NOTICE" INSTRUCTIONS BELOW.
X-RAY RADIATION PRECAUTION
1. Excessive high voltage can produce potentially hazard-
ous X-RAY RADIATION. To avoid such hazards, the high
voltage must not be above the specified limit. The nominal
value of the high voltage of this receiver is (A) kV at zero
beam current (minimum brightness) under a 120V AC
power source. The high voltage must not, under any cir-
cumstances, exceed (B) kV.
Refer to table-1 for high voltage (A), (B).
(See SETTING & ADJUSTING DATA on page 17)
Each time a receiver requires servicing, the high voltage
should be checked following the HIGH VOLTAGE CHECK
procedure in this manual. It is recommended that the read-
ing 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.
2. This receiver is equipped with a Fail Safe (FS) circuit which
prevents the receiver from producing an excessively high
voltage even if the B+ voltage increases abnormally. Each
time the receiver is serviced, the FS circuit must be checked
to determine that the circuit is properly functioning, follow-
ing the FS CIRCUIT CHECK procedure in this manual.
3. The only source of X-RAY RADIATION in this TV receiver
is the picture tube. For continued X-RAY RADIATION pro-
tection, the replacement tube must be exactly the same
type tube as specified in the parts list.
4. Some part in this receiver have special safety-related char-
acteristics for X-RAY RADIATION protection. For contin-
ued safety, parts replacement should be undertaken only
after referring to the PRODUCT SAFETY NOTICE below.
SAFETY PRECAUTION
Connect a 1500 ohm 10 watt resistor, paralleled by a 0.15
µF, AC type capacitor, between a known good earth ground
(water pipe, conduit, etc.) and the exposed metallic parts,
one at a time. Measure the AC voltage across the combi-
nation of 1500 ohm resistor and 0.15
µF capacitor. Re-
verse the AC plug at the AC outlet and repeat AC voltage
measurements for each exposed metallic part. Voltage
measured must not exceed 0.3 volts rms. This corresponds
to 0.2 milliamp. AC. Any value exceeding this limit consti-
tutes a potential shock hazard and must be corrected im-
mediately.
WARNING : Service should not be attempted by anyone unfa-
miliar with the necessary precautions on this receiver. The fol-
lowing are the necessary precautions to be observed before
servicing this chassis.
1. An isolation Transformer should be connected in the power
line between the receiver and the AC line before any serv-
ice is performed on the receiver.
2. Always discharge the picture tube anode to the CRT con-
ductive coating before handling the picture tube. The pic-
ture tube is highly evacuated and if broken, glass frag-
ments will be violently expelled. Use shatter proof gog-
gles and keep picture tube away from the unprotected body
while handling.
3. When replacing a chassis in the cabinet, always be cer-
tain that all the protective devices are put back in place,
such as; non-metallic control knobs, insulating covers,
shields, isolation resistor-capacitor network etc.
4. Before returning the set to the customer, always perform
an AC leakage current check on the exposed metallic parts
of the cabinet, such as antennas, terminals, screwheads,
metal overlays, control shafts etc. to be sure the set is
safe to operate without danger of electrical shock. Plug
the AC line cord directly into a 120V AC outlet (do not use
a line isolation transformer during this check). Use an AC
voltmeter having 5000 ohms per volt or more sensitivity in
the following manner:
AC VOLTMETER
0.15
µF
Good earth ground
such as a water
pipe, conduit, etc.
Place this probe on
each exposed
metallic part.
1500 ohm
10 watt
PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in this chassis have special safety-related characteristics. These characteristics are
often passed unnoticed by a visual inspection and the protection afforded by them cannot necessarily be obtained by using
replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety char-
acteristics are identified in this manual and its supplements; electrical components having such features are identified by
the international hazard symbols on the schematic diagram and the parts list.
Before replacing any of these components, read the parts list in this manual carefully. The use of substitute replacement
parts which do not have the same safety characteristics as specified in the parts list may create shock, fire, X-ray
radiation or other hazards.
4
GENERAL
ADJUSTMENTS
SPECIFIC
INFORMATIONS
WARNING: BEFORE SERVICING THIS CHASSIS, READ THE "X-RAY RADIATION PRECAUTION", "SAFETY PRECAU-
TION" AND "PRODUCT SAFETY NOTICE" ON PAGE 3 OF THIS MANUAL.
SET-UP ADJUSTMENT (FOR 13", 14", 19", 20")
s The following adjustments should be made when a complete realignment is required or a new picture tube is installed.
Perform the adjustments in order as follows :
1. Color Purity
2. Convergence
3. White Balance
Note: The PURITY/CONVERGENCE MAGNET assembly and rubber wedges need mechanical positioning.
Refer to figure 1.
Mounting position of the purity magnet assembly should fit to same position as old one because slightly difference to
the position depend on a kind of tube.
* There are no adjustment of purity and convergence in some picture tube (Unified with purity magnet)
GLASS CLOTH
TAPES
DEFLECTION
YOKE
TEMPORARY
MOUNTING
RUBBER WEDGE
ADHESIVE
DEFLECTION
YOKE
PURITY/
CONVERGENCE
MAGNET ASS'Y
14mm(13", 14")
19mm(19", 20")
Figure 1.
COLOR PURITY ADJUSTMENT
NOTE : Before attempting any purity adjustments, the receiver
should be operated for at least fifteen minutes.
1. Demagnetize the picture tube and cabinet using a degauss-
ing coil.
2. Set the brightness and contrast to maximum.
3. Use a green raster from among the built-in test signals.
4. Loosen the clamp screw holding the yoke and slide the
yoke backward or forward to provide vertical green belt
(zone) in the picture screen.
5. Remove the Rubber Wedges.
6. Rotate and spread the tabs of the purity magnet (See fig-
ure 2.) around the neck of the picture tube until the green
belt is in the center of the screen. At the same time, enter
the raster vertically.
7. Slowly move the yoke forward or backward until a uniform
green screen is obtained. Tighten the clamp screw of the
yoke temporarily.
8. Check the purity of the red and blue raster.