TOSHIBA 32A60 - Service Manual Immediate Download

TOSHIBA CORPORATION

1-1, SHIBAURA 1- CHOME, MINATO-KU, TOKYO 105-8001, JAPAN

FILE NO. 020-200016

SERVICE MANUAL

COLOR TELEVISION

N0S Chassis

27A60, 32A60, 36A60

(TAC0020)

PUBLISHED IN JAPAN,

Jun., 2000

(TAC0021)

(TAC0022)

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 ADJUSTMENT ................................................................................................................................ 12

CIRCUIT CHECKS ................................................................................................................................................. 16

CHAPTER 2 SPECIFIC INFORMATIONS

SETTING & ADJUSTING DATA .............................................................................................................................. 17

LOCATION OF CONTROLS ................................................................................................................................... 18

PROGRAMMING CHANNEL MEMORY ................................................................................................................. 20

CIRCUIT BLOCK DIAGRAM .................................................................................................................................. 21

CHASSIS AND CABINET REPLACEMENT PARTS LIST ......................................................................................22

PC BOARDS BOTTOM VIEW ................................................................................................................................. 31

TERMINAL VIEW OF TRANSISTORS ................................................................................................................... 35

SPECIFICATIONS .................................................................................................................................................. 37

APPENDIX:

CIRCUIT DIAGRAM

GENERAL

ADJUSTMENTS

SPECIFIC

INFORMATIONS

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.

CHAPTER 1 GENERAL ADJUSTMENTS

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.

GENERAL

ADJUSTMENTS

SPECIFIC

INFORMATIONS

CONVERGENCE ADJUSTMENTS

NOTE: Before attempting any convergence adjustments, the

receiver should be operated for at least fifteen min-

utes.

CENTER CONVERGENCE ADJUSTMENT

1. Use the cross-dot pattern from among the built-in test sig-

nals.

2. Set the brightness and contrast for well defined pattern.

3. Adjust two tabs of the 4-Pole Magnets to change the an-

gle between them (See figure 2.) and superimpose red

and blue vertical lines in the center area of the picture

screen.

4. Turn the both tabs at the same time keeping the angle

constant to superimpose red and blue horizontal lines at

the center of the screen.

5. Adjust two tabs of 6-Pole Magnets to superimpose red/

blue line and green one. Adjusting the angle affects the

vertical lines and rotating both magnets affects the hori-

zontal lines.

6. Repeat adjustments 3, 4, 5 keeping in mind red, green

and blue movement, because 4-Pole Magnets and 6-Pole

Magnets have mutual interaction and make dot movement

complex.

CIRCUMFERENCE CONVERGENCE ADJUSTMENT

1. Loosen the clamping screw of deflection yoke slightly to

allow the yoke to tilt.

2. Temporarily put a wedge as shown in figure 1. (Do not

remove cover paper on adhesive part of the wedge.)

3. Tilt front of the deflection yoke up or down to obtain better

convergence in circumference. (See figure 3.) Push the

mounted wedge into the space between picture tube and

the yoke to fix the yoke temporarily.

4. Put other wedge into bottom space and remove the cover

paper to stick.

5. Tilt front of the yoke right or left to obtain better conver-

gence in circumference. (See figure 3.)

6. Keep the yoke position and put another wedge in either

upper space. Remove cover paper and stick the wedge

on picture tube to fix the yoke.

7. Detach the temporarily mounted wedge and put it in an-

other upper space. Stick it on picture tube to fix the yoke.

8. After fixing three wedges, recheck overall convergence.

Tighten the screw firmly to fix the yoke and check the yoke

is firm.

9. Stick three adhesive tapes on wedges as shown in figure

Figure 2.

BLU

RED

BLU

RED

RED/BLU GRN

RED/BLU

GRN

BGR

RGB

BGR

RGB

4-POLE MAGNETS MOVEMENT

INCLINE THE YOKE UP (OR DOWN)

6-POLE MAGNETS MOVEMENT

Center Convergence by Convergence Magnets

Circumference Convergence by DEF Yoke

INCLINE THE YOKE RIGHT (OR LEFT)

Figure 3. Dot Movement Pattern

4-POLE

MAGNETS

PURITY

MAGNETS

6-POLE

MAGNETS

ADJUST THE ANGLE

(VERTICAL LINES)

FIXED

ROTATE TWO TABS

AT THE SAME TIME

(HORIZONTAL LINES)

CONVERGENCE MAGNET ASSEMBLY

ADJUSTMENT OF MAGNETS