Toshiba 28Z23B, 32Z23B Schematic
FILE NO. 033-200222
SERVICE MANUAL
COLOUR TELEVISION
Z23B Chassis
32Z23B, 28Z23B
– SUMMARY –
32Z23B, 28Z23B are the same as 32Z23G except for the parts tabled on back of this sheet.
Use this service manual together with the original service manual of 32Z23G, 28Z23G (File
No. 030-200216).
PUBLISHED IN JAPAN, Jul., 2002 So
REPLACEMENT PARTS LIST DIFFERENCES
Location
No.
C114 24797229 EL, 2.2?F, ±20%, 50V
CV26 24797470 EL, 47?F, ±20%, 50V
CV39 24794220 EL, 22?F, ±20%, 16V
CV41 24794220 EL, 22?F, ±20%, 16V
H001 23321413 Tuner, TEDB7-205A
L161 23262300 Coil, IF, TRF1246AV
* P801 23372151 Power Cord
QA01 23009166 IC, SAA5563/0620
RV18 24366472 CF, 4700 ohm
RV25 24366222 CF, 2200 ohm
RV60 24366561 CF, 560 ohm
RV61 24366561 CF, 560 ohm
U902 23787678 SIGNAL Board, PD0720A
*
U902 23787680 SIGNAL Board, PD0720C
*
U903 23787674 POWER & DEF Board,
*
U903 23787677 POWER & DEF Board,
*
* Y101 23565660 Owner’s Manual, English,
Y131 23589236 QSUG
Z102 23303237 Filter, 38MHZ, K9353M
Z103 23303186 Ceramic Trap, TCF1111
Part No. Description
(32Z23B)
(28Z23B)
PD0721A (32Z23B)
PD0721D (28Z23B)
32Z23B/28Z23B
TOSHIBA CORPORATION
1-1, SHIBAURA 1-CHOME, MINATO-KU, TOKYO 105-8001, JAPAN
FILE NO. 030-200216
SERVICE MANUAL
COLOUR TELEVISION
Z23B Chassis
32Z23G, 28Z23G
PUBLISHED IN JAPAN Jun. 2002 So
TABLE OF CONTENTS
CHAPTER 1 GENERAL ADJUSTMENTS
SAFETY INSTRUCTIONS ........................................................................................................................................3
SET-UP ADJUSTMENT ............................................................................................................................................ 4
SERVICE MODE ...................................................................................................................................................... 6
DESIGN MODE ........................................................................................................................................................ 9
ELECTRICAL ADJUSTMENTS .............................................................................................................................. 10
CIRCUIT CHECK .................................................................................................................................................... 12
CHAPTER 2 SPECIFIC INFORMATIONS
GENERAL ADJUSTMENTS
SETTING & ADJUSTING DATA ..............................................................................................................................13
LOCATION OF CONTROLS ................................................................................................................................... 14
CHASSIS AND CABINET REPLACEMENT PARTS LIST ......................................................................................16
PC BOARDS BOTTOM VIEW................................................................................................................................. 27
TERMINAL VIEW OF TRANSISTORS ................................................................................................................... 33
CIRCUIT BLOCK DIAGRAM .................................................................................................................................. 35
SPECIFICATIONS .............................................................................................................................................. END
APPENDIX:
CIRCUIT DIAGRAM
SPECIFIC INFORMATIONS
– 2 –
CHAPTER 1 GENERAL ADJUSTMENTS
SAFETY INSTRUCTIONS
WARNING: BEFORE SERVICING THIS CHASSIS, READ THE “X-RAY RADIATION PRECAUTION”, “SAFETY PRE-
CAUTION” 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;
non-metallic control knobs, insulating covers, shields, isolation resistor-capacitor network etc.
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.
SPECIFIC INFORMATIONS
– 3 –
WARNING: BEFORE SERVICING THIS CHASSIS, READ THE “X-RAY RADIATION PRECAUTION”, “SAFETY PRE-
CAUTION” 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.
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.
GENERAL ADJUSTMENTS
There are no adjustment of purity and convergence in some picture tube (Unified with purity magnet)
*
COLOR PURITY ADJUSTMENT
NOTE : Before attempting any purity adjustments, the re-
ceiver should be operated for at least fifteen minutes.
1. Demagnetize the picture tube and cabinet using a degaussing 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.
SPECIFIC INFORMATIONS
DEFLECTION
YOKE
29.1mm(28", 29")
25mm(25")
19mm(19", 20", 21")
14mm(13", 14")
5. Remove the Rubber Wedges.
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.
TEMPORARY
MOUNTING
RUBBER WEDGE
GLASS CLOTH
TAPES
PURITY/
CONVERGENCE
MAGNET ASS'Y
ADHESIVE
DEFLECTION
YOKE
Figure 1.
– 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
2. DISPLAYING THE ADJUSTMENT MENU
GENERAL ADJUSTMENTS
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.
A single horizontal line ON/OFF: INFO button (on Remote) or a button (on TV)
SPECIFIC INFORMATIONS
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
Item
Data
(Service mode display)
Service mode
Press
Press
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)
S
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)
Signals Picture
• Red raster
• Green raster
• Blue raster
• All White
• Black cross-hatch
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.
<SELF CHECK>
23******
POWER : 00
BUS LINE : OK
BUS CONT : OK
BLOCK :
GENERAL ADJUSTMENTS
UV V1 V2 V3
QV01
Indicated color of mode now selected : Green and Red
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---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
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.
*
NOTE: Component which controls character display on
screen is ICF01 (QT01) (TELETEXT IC.). If this
display function fails to operate due to damage in
ICF01 (QT01), 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.
– 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”, “OPT1” and “OPT2” 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”, “OPT1” and “OPT2”.
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)
Note: Constrict the picture height
until the vertical retrace line
appears adjusting the item
GENERAL ADJUSTMENTS
SPECIFIC INFORMATIONS
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 ap-
pears 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 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 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 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. Receive the Black and White pattern.
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 –
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
CIRCUIT CHECK
SPECIFIC INFORMATIONS
– 12 –
CHAPTER 2 SPECIFIC INFORMATIONS
SETTING & ADJUSTING DATA
SAFETY INSTRUCTIONS
HIGH VOLTAGE AT ZERO BEAM: (A) 31.9 kV
MAX HIGH VOLTAGE: (B) 34.0 kV
AC VOLTAGE
Table-1
SERVICE MODE
ADJUSTING ITEMS AND DATAS IN THE SERVICE MODE:
32”, 28”
(C) 220~240 V
GENERAL ADJUSTMENTS
Item
RCUT
GCUT
BCUT
GDRV
BDRV
BRTC
COLP
COLS
SCNT
SRY
SBY
HPOS
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 BRIGHT CEN
SUB COLOR CEN PAL
SUB COLOR CEN SECAM
SUB CONTRAST
SECAM R-Y
SECAM B-Y
H-POSITION (WIDE)
Adjustment
Item Name of adjustment Preset Data Data Remarks
* There are no adjustments of the design mode.
Reference data
40H
40H
40H
40H
40H
40H
3CH
3CH
07H
08H
07H
09H
←
←
←
←
←
←
←
←
←
←
←
07H
Item
VPOS1
HIT
VLIN
WID
PARA
CNR
TRAP
RAGC
CSAW
CPAR
HSC
Table-2
Adjustment
V-POSITION (WIDE)
HEIGHT (WIDE)
V-LINEARITY (WIDE)
PICTURE WIDTH (WIDE)
E-W PARABOLA (WIDE)
E-W CORNER (WIDE)
TRAPEZIUM (WIDE)
RF AGC
CENTER SAW
CENT PARA
E-W S CORR
Reference data
80H
34H
13H
34H
15H
18H
3BH
27H
06H
05H
10H
←
←
←
22H
11H
0FH
3CH
←
05H
02H
12H
SPECIFIC INFORMATIONS
Table-3
– 13 –
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