Toshiba 36A43 User Manual

FILE NO. 020-200303

DOCUMENT CREATED IN JAPAN, Mar., 2003

SERVICE MANUAL

COLOR TELEVISION

N3ES Chassis

36A43

(TAC0302)

CHAPTER 1 GENERAL ADJUSTMENTS

SAFETY INSTRUCTIONS ........................................................................................................................................ 3

SET-UP ADJUSTMENT ............................................................................................................................................ 4

SERVICE MODE ...................................................................................................................................................... 6

DESIGN MODE ........................................................................................................................................................ 9

ELECTRICAL ADJUSTMENT ................................................................................................................................ 10

CIRCUIT CHECKS ................................................................................................................................................. 12

GENERAL ADJUSTMENTS

CHAPTER 2 SPECIFIC INFORMATIONS

SETTING & ADJUSTING DATA .............................................................................................................................. 13

LOCATION OF CONTROLS ................................................................................................................................... 14

PROGRAMMING CHANNELS INTO THE TV'S MEMORY .................................................................................... 15

CHASSIS AND CABINET REPLACEMENT PARTS LIST ......................................................................................16

PC BOARDS BOTTOM VIEW................................................................................................................................. 25

TERMINAL VIEW OF TRANSISTORS ................................................................................................................... 28

CIRCUIT BLOCK DIAGRAM .................................................................................................................................. 30

TABLE OF CONTENTS

SPECIFIC INFORMATIONS

SPECIFICATIONS .............................................................................................................................................. END

APPENDIX:

CIRCUIT DIAGRAM

– 2 –

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 hazardous
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 cir­cumstances, exceed (B) kV.

Refer to table-1 for high voltage (A), (B).
(See SETTING & ADJUSTING DATA on page 13)

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 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.

SAFETY PRECAUTION

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, follow­ing 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 pro­tection, 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 char­acteristics for X-RAY RADIATION protection. For contin­ued safety, parts replacement should be undertaken only
after referring to the PRODUCT SAFETY NOTICE below.

GENERAL ADJUSTMENTS

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. An isolation Transformer should be connected in the power
line between the receiver and the AC line before any serv­ice is performed on the receiver.

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 shatter proof 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; 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:

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 combi­nation of 1500 ohm resistor and 0.15 µF capacitor. Re­verse 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 consti­tutes a potential shock hazard and must be corrected im­mediately.

AC VOLTMETER

0.15µF

Place this probe on

Good earth ground
such as a water
pipe, conduit, etc.

1500 ohm
10 watt

each exposed
metallic part.

SPECIFIC INFORMATIONS

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 char­acteristics 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.

– 3 –

WARNING: BEFORE SERVICING THIS CHASSIS, READ THE “X-RAY RADIATION PRECAUTION”, “SAFETY PRECAU-

TION” AND “PRODUCT SAFETY NOTICE” ON PAGE 3 OF SERVICE MANUAL.

■ 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.

COLOR PURITY ADUSTMENT

GENERAL ADJUSTMENTS

(1)Let the screen face in the installing direction or toward the east (when it is to be moved), bring up the service mode

screen after demagnetizing (front, left, right, and top) with the degaussing coil, receive white signals by pressing the
[TV/VIDEO] button, and then the receiver should be operated for more than 40 minutes.

(2)Perform rough adjustment of the central convergence with the P/C magnet according to the adjustment item.

(3)Receive built-in green signals, loosen set screws on the deflection yoke, remove rubber wedges, and shift the deflection

yoke to toward front.

(4)Move alternately the two 2-pole magnets of the P/C magnets so that the green raster can come to the center of the

screen.

SET-UP ADJUSTMENT

Figure 1.

(27": Magnet is fixed with deflection yoke.)

SPECIFIC INFORMATIONS

Green Belt

(5)Receive built-in red and blue signals, check that there is no inclination of the single color raster toward one side, and if

each color tilts to a great extent, make adjustment with the 2-pole magnet so that the 3 colors will come to the center
evenly.

(6)Receive the green raster, shift the deflection yoke from a

foremost position (hitting against the picture tube) to a
backward position horizontally, stop the deflection yoke
at a position where it begins to become a green raster,
and perform accurate marking on the picture tube.

(7)Shift the deflection yoke further backward, and perform

accurate marking at a position where the green raster
begins to being luck.

(8)Fix the deflection yoke at a position 60% forward within

the range marked in items (6) and (7) above.

CONVERGENCE ADJUSTMENTS

* Adjust the convergence magnet to get vest convergence in the the order to (1) ~ (5).

■ CENTER CONVERGENCE:

(1)Receive the white crosshatch or dot pattern from the service signal generator.

(2)Use the 2 pieces of main 4-pole magnets of P/C magnets, change the open angle, and align the red and blue vertical

lines on the screen center.

(3)Freeze the open angle of the main 4-pole magnets, turn them simultaneously, and align the horizontal lines.

(4)Take the same steps for items (2) and (3) above and align red/blue with green on the screen center using two 6-pole

magnets.

2-pole purity magnet

Main 4-pole convergence magnet (30" : 32")
6-pole convergence magnet (34")
6-pole convergence magnet (30" : 32")
Main 4-pole convergence magnet (34")

P/C magnet installing position A

• 30"=26.5 mm

A

Sub-4-pole convergence magnet (32" : 34")
Sub-4-pole convergence magnet (to be installed on deflection yoke for 30", 32”)

Picture tube

• 32"=30.5 mm or 32.5 mm

• 34"=37 mm

• 34"=39 mm

Shift deflection yoke

(7) Perform marking of each point

(6)

(8)

on the tape of picture tube

CRT-D board

100 60 0%

Fix the deflection yoke at a position 60% forward from a
point between (6) and (7)

P/C Mag

– 4 –

(5)Adjust the sub-4-pole magnets only in case there is any deviation of Xv bow-shaped convergence. (To be usually set at

the initial position)

Align both sides with the sub-4-pole magnets and minimize the deviation of blue and red with the main 4-pole magnets.

blue

blue
red

red

Main 4-pole magnet

red/blue

red/blue

green

6-pole magnet

■ CIRCUMFERENCE CONVERGENCE:

Perform correction in the following manner.

*

blue

green
red

A

B

C

(Parts code:23 948 274) TC-S

blue

green

red

S
N

Blue color or blue mark

D

E

F

*Insert the correction piece between the
picture tube and the deflection yoke.

Bonded surface

(Insertion position of correction
piece)

D

E

F

A

B

C

Adjust VR 1 and minimize the deviation of YH. *Only 27", 30" and 32".

Red

green

blue

blue

green

Red

Xv bow-shaped deviation of convergence

blue

green

red

Sub-4-pole magnet

• Adjust coils and minimize deviation
(The 27” unit has coils underneath it)

A

B

C

■ 30", 27", 32"

blue

green

red

(Parts code:23 948 464)

N
S

D

E

F

Bonded surface

GENERAL ADJUSTMENTS

SPECIFIC INFORMATIONS

Red

green

blue

blue

green

Red

Adjust VR 2 (YHC) and minimize the deviation of YH.

Red

blue

green

green

blue

Red

blue

Red

green

green

Red

blue

Adjust VR 3 (YV) and minimize the deviation of YV.

Red

green

blue

blue

green

Red

GH

Red

blue

green

green

blue

red

green

blue

red

green

green

Red

– 5 –

blue

Red

Red

blue

blue

green

VR3

VR2 VR1

■ 34"

YV YHC

27" (Part No. 23 947 371)
32", 30" (Part No. 23 947 121)
34" (Part No. 23 993 080)

GH

Perform correction by inserting the

correction piece into the clear­ance of terminal board coils of
the deflection yoke.

Note:

Perform insertion by turning the

metal side to the terminal board
side of the deflection yoke.

1. ENTERING TO SERVICE MODE

1) Press MUTE button once
on Remote Control.

MUTE

SERVICE MODE

2) Press MUTE button
again to keep pressing.

3) While pressing the MUTE button,
press MENU button on TV set.

S

(Service mode display)

GENERAL ADJUSTMENTS

2. DISPLAYING THE ADJUSTMENT MENU

1) Press MENU button on TV.

Service mode

3. KEY FUNCTION IN THE SERVICE MODE

The following key entry during display of adjustment menu provides special functions.

SPECIFIC INFORMATIONS

A single horizontal line ON/OFF: TV (ANT)/VIDEO button (on TV)
Test signal selection : TV (ANT)/VIDEO button (on Remote)
Selection of the adjustment items : Channel s/t (on TV or Remote)
Change of the data value : Volume T / S (on TV or Remote)
Adjustment menu mode ON/OFF : MENU button (on TV)
Initialization of the memory (QA02) : RECALL+Channel (s) button on TV
Initialization of the self diagnostic data: RECALL+Channel (t) button on TV

“RCUT” selection : 1 button
“GCUT” selection : 2 button
“BCUT” selection : 3 button
“CNTX” selection : 4 button
“COLC” selection : 5 button
“TNTC” selection : 6 button

Test audio signal ON/OFF (1kHz): 8 button
Self diagnostic display ON/OFF : 9 button

Adjustment mode

S

Press

Press

Item

Data

– 6 –

4. SELECTING THE ADJUSTING ITEMS

1) Every pressing of CHANNEL s button in the service mode changes the adjustment items in the order of table-2.
(t button for reverse order)

Refer to table-2 for preset data of adjustment mode.
(See SETTING & ADJUSTING DATA on page 13)

5. ADJUSTING THE DATA

1) Pressing of VOLUME T / S button will change the value of data in the range from 00H to FFH. The variable range

depends on the adjusting item.

6. EXIT FROM SERVICE MODE

1) Pressing POWER button to turn off the TV once.

■ INITIALIZATION OF MEMORY DATA OF QA02

After replacing QA02, the following initialization is required.

1. Enter the service mode, then select any register item.

2. Press and hold the CALL button on the Remote, then press the CHANNEL s button on the TV. The initialization of QA02 has
been complated.

3. Check the picture carefully. If necessary, adjust any adjustment item above.
Perform “Auto search Memory” on the owner’s manual.

CAUTION: Never attempt to initialize the data unless QA02 has been replaced.

7. TEST SIGNAL SELECTION

1) Every pressing of TV/VIDEO button on the Remote Control in the Service mode changes the built-in test patterns
on screen in the following order.

GENERAL ADJUSTMENTS

Normal picture Black cross-bar

on green raster

Red raster

Green raster

Blue raster

All black

All white

White and black

Black cross-bar

White cross-bar

2) Press "8" button while any built-in test pattern to on the screen to
output the 1 kHz sound. Press the button again to cut off the sound.

Note: If the video cable is connected to the VIDEO1 INPUT jack, the

built-in pattern signals are not displayed.

H signal (black)

H signal (white)

White cross-dot

Black cross-dot

White cross-hatch

Black cross-hatch

Signals Picture

• Red raster

• Green raster

• Blue raster

• All Black

• All White

• Black & White

• Black cross-bar

• White cross-bar

• Black cross-bar
on green raster

• Black cross-hatch

• White cross-hatch

• Black cross-dot

• White cross-dot

SPECIFIC INFORMATIONS

• H signal (white)

• H signal (black)

The signals marked with are not usable to display in the Test signal for some model.

*

– 7 –

8. SELF DIAGNOSTIC FUNCTION

1) Press “9” button on Remote Control during display of adjustment menu in the service mode.
The diagnosis will begin to check if interface among IC’s are executed properly.

2) During diagnosis, the following displays are shown.










GENERAL ADJUSTMENTS

 Part number of microprocessor (QA01)

 Operation number of protection circuit (current limiter) . . . . “000” is normal.

 BUS line check “OK” ................... Normal

 BUS line ACK (acknowledge) check

SELF CHECK
NO. 23
POWER : 000
BUS LINE : OK
BUS CONT : OK
BLOCK : MAIN
SET ID : 03
E2P VER : 02
OPT0 : 20H OPT1 : 84H OPT2 :01H

SPECIFIC INFORMATIONS

 SYNC signal available/not available (available: green, not available: red)
 SET ID
 Version of E2P
 OPT data

******

“SCL-GND” or “NG” .............. SCL-GND short circuit

“SDA-GND” or “NG” ............. SDA-GND short circuit

“SCL-SDA” or “NG” .............. SCL-SDA short circuit

“OK” ..................... Normal

Display of Location Number . . . . NG

(Display example)
“QA02 NG”, “H001 NG”, “Q501 NG” etc.
Note: The indication of failure place is only one place though failure places are plural. When repair

of a failure place finishes, the next failure place is indicated. (The order of priority of indica­tion is left side.)

The item marked with are not usable to display in the SELF DIAGNOSTIC FUNCTION for some model.

*

– 8 –

1. ENTERING TO DESIGN MODE

1) Select the Service mode.

DESIGN MODE

2) While pressing RECALL button on
Remote and press MENU button on TV.

3) Press MENU button on TV.

S D

(Design mode) (Adjustment mode)

When QA02 is initialized, items “OPT0” and “OPT1” of DESIGN MODE are set to the data of the representative model of this
chassis family.
Therefore, because ON-SCREEN specification remains in the state of the representative of model. This model is required to
reset the data of items “OPT0” and “OPT1”.

2. SELECTING THE ADJUSTING ITEMS

Every pressing of CHANNEL t button in the design mode changes the adjustment items in the order of table-3.
(s button for reverse order)

Refer to table-3 for data of design mode.
(See SETTING & ADJUSTING DATA on page 13)

3. ADJUSTING THE DATA

Pressing of VOLUME s or t button will change the value of data.

Press

Press

ITEM

DATA

GENERAL ADJUSTMENTS

SPECIFIC INFORMATIONS

– 9 –