Toshiba 36ZT29B Schematic

FILE NO. 030-200214

SERVICE MANUAL

COLOUR TELEVISION

ZD26 Chassis

36ZT29B

PUBLISHED IN JAPAN Jun. 2002 So

CHAPTER 1 GENERAL ADJUSTMENTS

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

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

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

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

ELECTRICAL ADJUSTMENTS .............................................................................................................................. 10

CIRCUIT CHECK .................................................................................................................................................... 12

GENERAL ADJUSTMENTS

CHAPTER 2 SPECIFIC INFORMATIONS

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

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

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

PC BOARDS BOTTOM VIEW................................................................................................................................. 37

TERMINAL VIEW OF TRANSISTORS ................................................................................................................... 46

CIRCUIT BLOCK DIAGRAM .................................................................................................................................. 48

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

TABLE OF CONTENTS

SPECIFIC INFORMATIONS

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 (C) V AC power
source. The high voltage must not, under any circumstances,
exceed (B) kV.

Refer to table-1 for high voltage (A), (B) & AC voltage (C).
(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.

2. 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.

3. 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

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. 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; non­metallic control knobs, insulating covers, shields, isolation resistor-capacitor network etc.

PRODUCT SAFETY NOTICE

SPECIFIC INFORMATIONS

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 THIS MANUAL.

SET-UP ADJUSTMENT

■ 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.

GENERAL ADJUSTMENTS

*

COLOR PURITY ADJUSTMENT
NOTE : Before attempting any purity adjustments, the receiver

1. Demagnetize the picture tube and cabinet using a degauss-

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

SPECIFIC INFORMATIONS

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)

5. Remove the Rubber Wedges.

should be operated for at least fifteen minutes.

ing coil.

yoke backward or forward to provide vertical green belt
(zone) in the picture screen.

6. Rotate and spread the tabs of the purity magnet (See fig­ure 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.

GLASS CLOTH
TAPES

DEFLECTION
YOKE

29.1mm(28", 29")
25mm(25")
19mm(19", 20", 21")
14mm(13", 14")

PURITY/
CONVERGENCE
MAGNET ASS'Y

Figure 1.

TEMPORARY
MOUNTING

RUBBER WEDGE

ADHESIVE

DEFLECTION
YOKE

– 4 –

CONVERGENCE ADJUSTMENTS

NOTE: Before attempting any convergence adjustments, the

receiver should be operated for at least fifteen min­utes.

■ CENTER CONVERGENCE ADJUSTMENT

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

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

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

6-POLE

4-POLE

MAGNETS

MAGNETS

ADJUST THE ANGLE
(VERTICAL LINES)

■ 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 conver­gence 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 an­other 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

1.

FIXED

GENERAL ADJUSTMENTS

ROTATE TWO TABS
AT THE SAME TIME
(HORIZONTAL LINES)

PURITY
MAGNETS

CONVERGENCE MAGNET ASSEMBLY ADJUSTMENT OF MAGNETS

Figure 2.

BLU RED

BLU

RED

4-POLE MAGNETS MOVEMENT

BGR

R
G
B

RGB

RED/BLU

GRN

Center Convergence by Convergence Magnets

B
G
R

RED/BLU GRN

6-POLE MAGNETS MOVEMENT

B
G
R

BGR

RGB

R
G
B

SPECIFIC INFORMATIONS

INCLINE THE YOKE UP (OR DOWN)

Circumference Convergence by DEF Yoke

Figure 3. Dot Movement Pattern

INCLINE THE YOKE RIGHT (OR LEFT)

– 5 –

1. ENTERING TO SERVICE MODE

1) Press o button once on
Remote Control.

SERVICE MODE

2) Press o button again to
keep pressing.

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

Mute or

GENERAL ADJUSTMENTS

2. DISPLAYING THE ADJUSTMENT MENU

1) Press MENU button on TV.

Adjustment mode

ITEM

DATA

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: INFO button (on Remote) or a button (on TV)
Test signal selection : a button (on Remote)
Selection of the adjustment items : Channel s/t (on TV or Remote)
Change of the data value : Volume ; +/– (on TV or Remote)
Adjustment menu mode ON/OFF : MENU button (on TV)
Initialization of the memory (QA02) : CALL + Channel button on TV (s)
Reset the count of operating protect

circuit to “00”: CALL + Channel button on TV (t)

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

Self diagnostic display ON/OFF : 9 button

Item

Data

Press

Press

Item

Data

(Service mode display)

Service mode

S

S

Color thickness correction
note: Displayed differently as shown below, de-

pending on the setting of the receiving color
system.
COLP (PAL)
COLC (NTSC)
COLS (SECAM)

CAUTION : Never try to perform initialization unless you have changed the memory IC.

– 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 ; +/– 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 a button on the Remote Control changes the built-in test patterns on screen as described below
in SERVICE MODE.

GENERAL ADJUSTMENTS

Signal off

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

*

NTSC signals (5 patterns)

PAL signals (5 patterns)

• Red raster

• Green raster

• Blue raster

• All White

• Black cross-hatch

Signals Picture

SPECIFIC INFORMATIONS

– 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.

Indicated color of mode now selected : Green and Red

<SELF CHECK>

23******



POWER : 00



BUS LINE : OK



BUS CONT : OK



BLOCK :



UV V1 V2 V3
QV01

Indicated color of other modes : White

Green : Normal
Red : The microcomputer operates to provide judgement

of no video signal. The red color is still indicated
though the signal is input, failure may exist in input
signal line including QV01.

QV01 : In case of indication green ---Normal

In case of indication red with input signal----

GENERAL ADJUSTMENTS

Failure may exist in output line including QV01.

 Part number of microcomputer (QA01)
 Operation number of protecting circuit ----“00” is nor-

mal.
When indication is other than “00”, overcurrent apts to
flow, and circuit parts may possibly be damaged.

 BUS LINE CHECK ----“OK” is normal.

“SDA1-GND” ------------- SDA-GND short circuit.
“SCL1-GND” -------------- SCL-GND short circuit.
“SCL1-SDA1” ------------- SCL-SDA short circuit.

 BUS CONT ----“OK” is normal.

When indication shows “Q uuu NG”, the device with

SPECIFIC INFORMATIONS

the number may possibly be damaged.

 BLOCK

NOTE: Component which controls character display on

screen is ICF01 (TELETEXT IC.). If this display
function fails to operate due to damage in ICF01,
self diagnosis procedure is as follows.
(1) In case that power indicator is blinking with

interval of 0.5 seconds; it means protecting
circuit (Current limiter) is operating, and cir­cuit components may possibly be damaged.
Check related components.

(2) In case that power indicator is blinking with

interval of 1 second; Protecting circuit does
not operate, but a part of Bus line does not
operate normally. Check Bus line.

UV : TV reception mode
V1 : VIDEO 1 input mode (a1)
V2 : VIDEO 2 input mode (a2)
V3 : VIDEO 3 input mode (a3)

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

*

– 8 –

1. ENTERING TO DESIGN MODE

1) Select the Service mode.

DESIGN MODE

2) While pressing o or CALL 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 –

ELECTRICAL ADJUSTMENTS

ITEM ADJUSTMENT PROCEDURE

FOCUS VR ADJ

SUB-BRIGHTNESS
(BRTC)

GENERAL ADJUSTMENTS

SPECIFIC INFORMATIONS

Note: Constrict the picture height

until the vertical retrace line
appears adjusting the item
HIT (HEIGHT).

HORIZONTAL POSITION
ADJUSTMENT (HPOS)

VERTICAL POSITION
ADJUSTMENT (VPOS)

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

2. Press the TV/VIDEO button on the Remote until the black cross-bar pattern ap­pears on the screen.

3. Adjust the FOCUS control (on T461) for well defined scanning lines on the picture
screen.

1. Set CONTRAST to minimum, and
BRIGHTNESS to center by adjusting
user controls.

2. Set the TV in service mode to get white
cross-bar of inside pattern.

3. Select BRTC (brightness correction),
and adjust the ; – /+ button to reduce
the value so that white portion of inside
pattern slightly light.

4. Adjust ; – /+ button to increase the
data value of BRTC, and set it just
before the difference between the belt of
vertical retrace and the border of black
portion of inside pattern is visible.
After that, return vertical height and
contrast.

1. Set the TV in service mode, and get
black or white cross-bar signal with
VIDEO button on remote hand unit.

2. Select either HPOS (Horizontal
picture phase) or VPOS (Vertical
picture phase) with CHANNEL s, t
buttons, and adjust horizontal or
vertical picture position in the center
of screen with VOLUME ; – /+
buttons.

Belt of vertical retrace

VERTICAL AMPLITUDE
ADJUSTMENT (HIT)

1. Set the TV in service mode, and get
black or white cross-hatch signal
with VIDEO button on remote hand
unit.

2. Select HIT (Vertical amplitude) with
CHANNEL s, t buttons, and adjust
vertical amplitude with VOLUME
; – /+ buttons so that vertical am­plitude lacks a little.

3. Adjust vertical amplitude with VOL­UME ; – /+ buttons so that the first
bar on cross-hatch signal touches
edge of screen.

The first

– 10 –

ITEM ADJUSTMENT PROCEDURE

WHITE BALANCE
ADJUSTMENT

CUTOFF ADJUSTMENT

•

(RCUT)
(GCUT)
(BCUT)

DRIVE ADJUSTMENT

•

(GDRV)
(BDRV)

1. Set Contrast to 40, and brightness to +20 by picture control.

2. Set the TV in service mode, and get the inside W/B adjusting signal with VIDEO

button.

3. Select RCUT, GCUT and BCUT with CHANNEL s, t buttons, to set individual

values to Initial reference data, and to set GDRV and BDRV to Initial reference
data with VOLUME ; – /+ buttons.

4. Press -/- - button on the remote control and rotate Screen VR to get one slight

horizontal line on screen.
Note: Every pressing of -/- - button provides Horizontal line picture and Normal
picture alternately.

5. Press -/- - button to release horizontal line picture, and select the two other colors

which did not light in the above step with CHANNEL s, t buttons. Then tap VOL­UME ; – /+ buttons so that three colors slightly light in the same level.

X To correct white balance in light area,

select GDRV and BDRV with CHANNEL
s, t buttons to adjust.

X To correct white balance in dark area,

perform fine adjustment of RCUT, GCUT
and BCUT.

Light area check

(to show white)

Dark area check

(to show black)

GENERAL ADJUSTMENTS

SPECIFIC INFORMATIONS

– 11 –

CIRCUIT CHECK

HIGH VOLTAGE CHECK
CAUTION: There is no HIGH VOLTAGE ADJUSTMENT on this chassis. Checking should be done following the steps

below.

1. Connect an accurate high voltage meter to the second anode of the picture tube.

2. Turn on the receiver. Set the BRIGHTNESS and CONTRAST controls to minimum (zero beam current).

3. High voltage must be measured below (B) kV.

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

4. Vary the BRIGHTNESS control to both extremes to be sure the high voltage does not exceed the limit under any conditions.

GENERAL ADJUSTMENTS

SPECIFIC INFORMATIONS

– 12 –

CHAPTER 2 SPECIFIC INFORMATIONS

SETTING & ADJUSTING DATA

SAFETY INSTRUCTIONS

HIGH VOLTAGE AT ZERO BEAM: (A) 33.4 kV
MAX HIGH VOLTAGE: (B) 35.0 kV
AC VOLTAGE

Table-1

SERVICE MODE

ADJUSTING ITEMS AND DATAS IN THE SERVICE MODE:

36”

(C) 220~240 V

GENERAL ADJUSTMENTS

Item

RCUT
GCUT
BCUT
GDRV
BDRV
CNTX
BRTC
COLC
TNTC
COLP
COLS
COLD
SCNT
SRY
SBY

DESIGN MODE

ADJUSTING ITEMS AND DATAS IN THE DESIGN MODE:

R CUTOFF (B/W)
G CUTOFF (B/W)
B CUTOFF (B/W)
R DRIVE
B DRIVE
SUB CONTRAST MAX
SUB BRIGHT CEN
SUB COLOR CEN NTSC
SUB TINT CEN
SUB COLOR CEN PAL
SUB COLOR CEN SECAM
SUB COLOR CEN DTV
SUB CONTRAST
SECAM R-Y
SECAM B-Y

Adjustment

Item Name of adjustment Preset Data Data Remarks

OPT0
OPT1
OPT2
OPT3
OPT4

Reference data

40H
40H
40H
35H
35H
7FH
80H

02H
1EH
05H
08H
41H
08H
07H
04H

Table-2

OPTION 0
OPTION 1
OPTION 2
OPTION 3
OPTION 4

Item

HPOS
VPOS
HIT
VLIN
VSC
VPS2
WID
PARA
CNR
TRAP
CPAR
HSC
VPSI
CSAW

Adjustment

50Hz H-POSITION
V-POSITION
HEIGHT
V-LINEARITY
V-S CORRECTION
V-SHIFT
PICTURE WIDTH
E-W PARABOLA
E-W CORNER
TRAPEZIUM
WIDE CENT PARA
WIDE EW S CORR
WIDE V-POS
WIDE CENT SAW

B0H
77H
10H
01H
2FH

←

←

←

←

←

Reference data

31H
00H
30H
10H

2DH

40H
25H
10H

1AH

45H
07H
10H
73H
08H

SPECIFIC INFORMATIONS

Table-3

– 13 –

Front

GENERAL ADJUSTMENTS

LOCATION OF CONTROLS

SPECIFIC INFORMATIONS

Rear terminals

DIGITAL

REC

GRN ORG GRN RED

VIDEO-3

MAIN SWITCH

(S-VIDEO TERMINAL)

POSITION UP

VIDEO-3

HEAD PHONE

POSITION DOWN

VOLUME UP

VOLUME DOWN

MENU

100Hz Dynamic Frame Scan

Progressive Scan

EXTERNAL SPEAKER SWITCH
(EXT/INT)

DIGITAL AUDIO INPUT
(OPTICAL/COAXIAL)

EXTERNAL SPEAKER TERMINAL

VIDEO-2 (21PIN S-VIDEO/AV)

VIDEO-3 (21PIN S-VIDEO/AV)

VIDEO-1 (21PIN S-VIDEO/AV)

SERIAL

MODEM

DVD COMMON INTERFACE

VCR/AERIAL TERMINAL

AUDIO OUT (FIXED)

VIDEO-4 (AUDIO IN)

VIDEO-4 (COMPONENT VIDEO)

– 14 –