Toshiba 25AF6SH User manual

SERVICE MANUAL
COLOUR TELEVISION
D1ES Chassis
FILE NO. 070-200112
25AF6SH
Dec. 2001
TOSHIBA CORPORATION
1-1, SHIBAURA 1- CHOME, MINATO-KU, TOKYO 105-8001, JAPAN

– 2 –
GENERAL ADJUSTMENTS
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
SETTING & ADJUSTING DATA ...................................................................................................................................... 13
LOCATION OF CONTROLS ........................................................................................................................................... 14
PROGRAMMING CHANNEL MEMORY ......................................................................................................................... 16
CIRCUIT BLOCK DIAGRAM .......................................................................................................................................... 18
CHASSIS AND CABINET REPLACEMENT PARTS LIST .............................................................................................. 19
PC BOARDS BOTTOM VIEW ......................................................................................................................................... 27
TERMINAL VIEW OF TRANSISTORS ........................................................................................................................... 33
SPECIFICATIONS ...................................................................................................................................................... END
APPENDIX:
CIRCUIT DIAGRAM

–3 –
GENERAL ADJUSTMENTS
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 (C) V AC power
source. The high voltage must not, under any circum-
stances, 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 volt-
age 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 pro-
tection, 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 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
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 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
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: 1.The PURITY/CONVERGENCE MAGNET assembly and rubber wedges need mechanical positioning.
Refer to figure 1.
2.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
29.1mm(28", 29")
25mm(25")
19mm(19", 20", 21")
14mm(13", 14")
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.

–5 –
GENERAL ADJUSTMENTS
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
1.
Figure 2.
BLU RED
BLU
RED
RED/BLU GRN
RED/BLU
GRN
B
G
R
R
G
B
BGR
RGB
BGR
RGB
R
G
B
B
G
R
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

–6 –
GENERAL ADJUSTMENTS
SERVICE MODE
1. ENTERING TO SERVICE MODE
S
(Service mode display)
Item
Data
3) While pressing the obutton,
press MENU button on TV set.
2) Press obutton again to
keep pressing.
2. DISPLAYING THE ADJUSTMENT MENU
1) Press MENU button on TV.
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: - / - - button (on Remote) or abutton (on TV)
Test signal selection : abutton (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
Test audio signal ON/OFF (1kHz) : 8 button
Self diagnostic display ON/OFF : 9 button
1) Press obutton once on
Remote Control.
Adjustment mode
Press
Press
Service mode
Item
Data
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.
* The key function marked with are not usable to control in the Test signal for some model.

–7 –
GENERAL ADJUSTMENTS
4. SELECTING THE ADJUSTING ITEMS
1) Every pressing of CHANNEL sbutton in the service mode changes the adjustment items in the order of table-2.
(tbutton 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 sbutton 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 abutton on the Remote Control changes the built-in test patterns on screen as described below
in SERVICE MODE.
Signals Picture
•Red raster
•Green raster
•Blue raster
•All Black
•All White
•Black & White
•Black cross-hatch
•White cross-hatch
•Black cross-dot
•White cross-dot
•Black cross-bar
•White cross-bar
•Black cross-bar
on green raster
•H signal (white)
•H signal (black)
* The signals marked with are not usable to display in the Test signal for some model.
Signal off NTSC signals (14 patterns)
PAL signals (14 patterns)

–8 –
GENERAL ADJUSTMENTS
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.
23******
POWER : 00
BUS LINE : OK
BUS CONT : OK
BLOCK : UV V1 V2
QV01
<SELF CHECK>
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
the number may possibly be damaged.
BLOCK
UV : TV reception mode
V1 : VIDEO 1 input mode (a1)
V2 : VIDEO 2 input mode (a2)
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.
NOTE: Component which controls character display on
screen is QT01 (TELETEXT IC.). If this display
function fails to operate due to damage in 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 cir-
cuit 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.





* The items marked with are not usable to display in the SELF DIAGNOSTIC FUNCTION for some model.

–9 –
GENERAL ADJUSTMENTS
DESIGN MODE
1. ENTERING TO DESIGN MODE
ITEM
DATA
S D Press
(Design mode) (Adjustment mode)
Press
3) Press MENU button on TV.
2) While pressing o(or CALL) button on
Remote and press MENU button on TV.
1) Select the Service mode.
2. SELECTING THE ADJUSTING ITEMS
Every pressing of CHANNEL tbutton in the design mode changes the adjustment items in the order of table-3.
(sbutton 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 sor tbutton will change the value of data.
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”.

–10 –
GENERAL ADJUSTMENTS
ELECTRICAL ADJUSTMENTS
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.
FOCUS VR ADJ
SUB-BRIGHTNESS
(BRTC)
Note: Constrict the picture height
until the vertical retrace line
appears adjusting the item
HIT (HEIGHT).
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 pat-
tern slightly light.
4. Adjust ;–/+ button to increase the data
value of BRTC, and set it just before the
difference between the belt of vertical re-
trace and the border of black portion of
inside pattern is visible.
After that, return vertical height and con-
trast.
ITEM ADJUSTMENT PROCEDURE
Belt of vertical retrace
HORIZONTAL POSITION
ADJUSTMENT (HPOS)
VERTICAL POSITION
ADJUSTMENT (VPOS)
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 pic-
ture phase) or VPOS (Vertical picture
phase) with CHANNEL s, tbuttons,
and adjust horizontal or vertical pic-
ture position in the center of screen
with VOLUME ;–/+ buttons.
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, tbuttons, and adjust
vertical amplitude with VOLUME
;–/+ buttons so that vertical am-
plitude lacks a little.
3. Adjust vertical amplitude with VOL-
UME ;–/+ buttons so that the first
bar on cross-hatch signal touches
edge of screen.
The first

–11 –
GENERAL ADJUSTMENTS
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, tbuttons, to set individual
values to Initial reference data, and to set GDRV and BDRV to Initial reference
data with VOLUME ;–/+ buttons (See page 19).
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, tbuttons. Then tap VOL-
UME ;–/+ buttons so that three colors slightly light in the same level.
XTo correct white balance in light area,
select GDRV and BDRV with CHANNEL
s, tbuttons to adjust.
XTo 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)
NOTE: It is released built-in test pattern by changing the adjustment item for some model.
In this case, select the adjustment item with channel st button first and then select the built-in test pattern
with -/- - button.

–12 –
GENERAL ADJUSTMENTS
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.

– 13 –
SPECIFIC INFORMATIONS
SETTING & ADJUSTING DATA
25"
HIGH VOLTAGE AT ZERO BEAM: (A) 32.8 kV
MAX HIGH VOLTAGE: (B) 33.0 kV
AC VOLTAGE (C) 110~240 V
CHAPTER 2 SPECIFIC INFORMATIONS
SAFETY INSTRUCTIONS
Table-1
SERVICE MODE
ADJUSTING ITEMS AND DATAS IN THE SERVICE MODE:
Item Adjustment Reference data
RCUT
GCUT
BCUT
GDRV
BDRV
BRTC
COLC
TNTC
COLP
COLS
SCNT
HPOS
VPOS
HIT
VLIN
WID
PARA
TRAP
SRY
SBY
R CUTOFF (B/W)
G CUTOFF (B/W)
B CUTOFF (B/W)
G DRIVE
B DRIVE
SUB BRIGHT CEN
SUB COLOR CEN NTSC
SUB TINT CEN
SUB COLOR CEN PAL
SUB COLOR CEN SECAM
SUB CONTRAST
50Hz H-POSITION
V-POSITION
HEIGHT
V-LINEARITY
PICTURE WIDTH
E-W PARABOLA
TRAPEZIUM
SECAM R-Y
SECAM-B-Y
20H
20H
20H
40H
40H
40H
45H
43H
FFH
00H
09H
10H
04H
2FH
07H
10H
16H
11H
07H
07H
Table-2
DESIGN MODE
ADJUSTING ITEMS AND DATAS IN THE DESIGN MODE:
Item Name of adjustment Preset Data Data Remarks
OPT 1 OPTION 1 26H 26H
OPT 2 OPTION 2 07H 07H
Table-3
←
←
←
←
←
←
←
←
←
←
←
←
03H
24H
08H
←
←
←
←
←
Data

–14 –
SPECIFIC INFORMATIONS
LOCATION OF CONTROLS
Front
Back
a(1) Video 1 input terminals
a(2) Video input terminals
Component video input terminals
MONITOR output terminals
Remote sensor
rON-TIMER (green)
qPower switch
c*Channel Position ts
Menu item select
;*Volume –+
Menu item select
aInput source selection
Bihind the door
a(3)Video 3 input
terminals
MENU
CH
L/MONO R
AUDIOVIDEO
(3)
S-VIDEO
VIDEO
COMPONENT
VIDEO INPUT
L/MONO
AUDIO
R
Y
P
B /C B
P R /C R
(2)(1)
(MONITOR)
Aerial input
qPower indicator (red)
MENU
Headphone jack (ø3.5 mm)
For private listening, connect headphones.
The sound from the speakers will be cut off
automatically.
To adjust the volume, press the –; +
buttons. *Dual function buttons.

–15 –
SPECIFIC INFORMATIONS
Remote
o Sound Mute
hPicture menu
8Sound menu
mI/II Stereo/Bilingual Selection
aInput source selection*
CALL
Number (0-9)
–/- - 1 or 2 digit selection
MENU*
89 Menu item select*
–+ Menu item adjust*
*These functions have duplicate
locations on the TV set.
123
456
789
–/-- 0
MENU
CALL
fPower on/standby
;Volume + –*
Channel position *

–16 –
SPECIFIC INFORMATIONS
PROGRAMMING CHANNEL MEMORY
•First, use the ASM (Automatic Search Memory) function to preset all the active channels in your
area automatically.
Then, arrange the preset channels with the SEARCH (>>>), MFT (Manual Fine Tuning) and
AFT (Auto Fine Tuning) functions so that you can tune into only desired channels.
•This section shows how to tune in channels using mainly the Remote Controller. You can also
perform the system select, ASM, SEARCH (>>>), SKIP, MFT and AFT operations using the
buttons on the TV set.
To preset channels (ASM)
ASM (Automatic Search Memory)
Select the head of the position number to start the
ASM with the position down ( )
/up ( ) buttons or the
digit/direct select buttons.
Press the MENU button repeatedly to call up the SET
UP menu on the screen.
Confirm that “COLOR”is set to “AUTO”and “SOUND”
is set to proper system.
If not, press the t/sbuttons to move the cursor (-) to
“COLOR”or “SOUND”and press the –/+buttons to
select each proper system.
Press the t/s buttons to move the cursor (-) to
“ASM”.
Press the “+”button to start the ASM. All active
channels will be preset automatically.
When presetting is complete, the initial position number
will reappear.
After presetting
Check the preset channels by pressing the position down
( )/up ( ) buttons.
•If the picture or sound of a certain channel is not good, fine-
tune the channel using the MFT function.
•If the colour of a certain channel is abnormal, automatic
colour system selection (AUTO) may malfunction, or sound
system selection is wrong. In such a case, select another
colour and/or sound system.
1
2
3
5
4
To preset channels
(Manual search, AFT, MFT)
1
2
3
4
5
7
6
Manual search (>>>)
Select a position number with the position down ( )/
up ( ) or digit/direct select buttons.
Press the MENU button repeatedly to call up the SET
UP menu on the screen.
Press the t/s buttons to move the cursor (-) to “>>>”.
Press the –/+buttons to start searching.
The – button searches for lower-numbered channels;
the
+ button for higher- numbered channels.
Repeat this process until you can get the desired channel.
When the desired programme is shown, press the t/s
buttons to move the cursor (-) to “ ”.
Press the +button to memorize the channel at the
current postion.
When you desire to store another channel at another
postion, move the cursor
( - ) to “POSITION”with the t/
s
buttons and select a desired position with the –/+
buttons.
Then, press the t/s buttons to move the cursor ( - )
to “>>>”and repeat the steps 4 to 7.
*Please refer to owners manual in details.

–17 –
SPECIFIC INFORMATIONS
•Use the SEARCH function if desired channels could not be preset with the ASM, or if you would
like to preset the desired channels to specific position numbers one by one.
•The adjustments below are not necessary under normal conditions. However, in areas of
inferior broadcast conditions where adjustment is necessary for a better picutre, adjust the
tuning with the MFT (Manual Fine Tuning). The AFT OFF status automatically keeps the
condition adjusted with the MFT function.
•The AFT (Auto Fine Tuning) function automatically corrects slight fluctuations when receiving
signals.
•When using Manual Search to preset the channel, the AFT will automatically turn ON and SKIP
to OFF.
MFT (Manual Fine Tuning)
Select the position number you want to fine-tune with
the position down ( )/up( ) buttons or digit/direct
select buttons.
Press the MENU button repeatedly to call up the SET
UP menu on the screen.
Press the t/s buttons to move the cursor (S) to
“MFT”.
Press the –/+ buttons until the best possible picture
and sound are obtained.
Note
When operating the MFT function, the AFT status is
automatically set to OFF.
AFT (Auto Fine Tuning)
Select the position number you want to fine-tune with
the position down ( )/up( ) buttons or digit/direct
select buttons.
Press the MENU button repeatedly to call up the SET
UP menu on the screen.
Press the t/s buttons to move the cursor (S) to
“AFT”. Press the –/+ buttons to select the “ON”
indication.
Note
When position is set to AFT OFF status, the “
R ”mark
appears to the left of the position number.
When the channel is set to AFT ON status, the
position number is displayed without the “
R ”mark.
1
2
3
4
1
2
3
After presetting the channels, you may skip unnecessary
position numbers so that only the channels you want to
watch are selected.
To skip a position number
Select the position number to be skipped with the
position down ( )/up ( ) buttons or digit/direct
select buttons.
Press the MENU button repeatedly to call up the SET
UP menu on the screen.
Press the t/s buttons to move the cursor (S) to
“SKIP”.
Press the –/+ buttons to select “SKIP ON”.
Press the MENU button to turn off the SET UP menu
display.
Select the position number to be skipped with the direct
select buttons. The *mark appears to the left of the
position number.
The position number will then be skipped when you
select channels with the position down ( )/up ( )
buttons.
To restore a skipped position number
1Select the position number you want to restore with the
direct select (and/or digit select) buttons.
2Press the MENU button to call up the SET UP menu
display and press the
t/s buttons to move the cursor (S)
to “SKIP”.
3Press the –/+ buttons to select “SKIP OFF”.
*Please refer to owners manual in details.
1
2
3
4
5
To skip unnecessary position numbers

–18 –
SPECIFIC INFORMATIONS
~
~
–+
TUNER IF/MPX
H001 H002
QT01
QV01
QA01
QA02
Q801
Z801
Q404
Q301
Q501
Q901,Q903,Q905
Q610
Q840
L/R
VIDEO L
/
R
AV IN
(1)
AV IN
(2)
MEMORY REGULATOR
RESET
µ-COM
I
2
C BUS R
G
B
HYBRID
CONVERTER TRANS.
+B VOLTAGE
C
Y
CHROMA
VIDEO
DEF.
VIDEO OUT
V. OUT
H. OUT
ERROR
AMP.
F.B.T.
H.V.
D.Y.
VH
CRT
AUDIO OUT
L
R
*
AV SW
*
TEXT
*
*
*
*
BUS CONTROL BLOCK
SV
V
L
R
R
MONITOR
OUTPUT
V
L
R
V
L
CHASSIS BLOCK DIAGRAM
COMB
FILTER
QZ01
CIRCUIT BLOCK DIAGRAM

– 19 –
SPECIFIC INFORMATIONS
LocationLocation
LocationLocation
Location Parts No.Parts No.
Parts No.Parts No.
Parts No. DescriptionDescription
DescriptionDescription
Description
No.No.
No.No.
No.
LocationLocation
LocationLocation
Location Parts No.Parts No.
Parts No.Parts No.
Parts No. DescriptionDescription
DescriptionDescription
Description
No.No.
No.No.
No.
CAPACITORS
C101 24794101 ELECTROLYTIC, 16 100UF M
C103 24669010 ELECTROLYTIC, 50 1.0UF M 3A
C105 24796479 ELECTROLYTIC, 35 4.7UF M
C112 24794101 ELECTROLYTIC, 16 100UF M
C132 24794100 ELECTROLYTIC, 16 10UF M
C135 24797229 ELECTROLYTIC, 50 2.2UF M
C140 24797478 ELECTROLYTIC, 50 0.47UF M
C141 24474102 CERAMIC, 50 B 1000PF K
C201 24073078 ELECTROLYTIC CE04P 50 0.22UF M 3A
C210 24591104 PLASTIC FILM, 50 0.1UF J
C216 24797010 ELECTROLYTIC, 50 1UF M
C221 24473100 CERAMIC CC141SL 50 10PF J
C222 24473100 CERAMIC CC141SL 50 10PF J
C223 24473100 CERAMIC CC141SL 50 10PF J
C224 24797100 ELECTROLYTIC, 50 10UF M
C225 24539104 PLASTIC FILM, 50 0.1UF J
C226 24539104 PLASTIC FILM, 50 0.1UF J
C233 24797010 ELECTROLYTIC, 50 1UF M
C303 24693473 PLASTIC FILM, 100 0.047UF J
C304 24214471 CERAMIC DISC, 500 B 470PF K
C306 24073059 ELECTROLYTIC, 25 3300UF M 3A
C307 24567393 PLASTIC FILM, 50 39000PF J
C308 24669221 ELECTROLYTIC CE04Q 50 220UF M 3A
C309 24669101 ELECTROLYTIC, 50 100UF M 3A
C310 24669222 ELECTROLYTIC, 50 2200UF M 3A
C313 24082058 PLASTIC FILM, 100 270000PF J
C316 24567223 PLASTIC FILM, 50 22000PF J
C318 24666101 ELECTROLYTIC, 16 100UF M 3A
C319 24212472 CERAMIC DISK CK45 B 50 4700PF K
C321 24539474 MT PLA CAP M 50 474J MUL
C341 24794101 ELECTROLYTIC, 16 100UF M
C342 24795100 ELECTROLYTIC CE04G 25 10UF M
C350 24693102 PLASTIC FILM, 100 1000PF J
C351 24591102 PLASTIC FILM, 50 1000PF J
C352 24617912 ELECTROLYTIC, 50 2.2UF K 3A LI
C361 24794220 ELECTROLYTIC, 16 22UF M
C363 24693104 PLASTIC FILM CQ921 M 100 0.1MF J
C403 24590822 PLASTIC FILM, 50 8200PF J
C404 24669478 ELECTROLYTIC, 50 0.47UF M 3A
C406 24797010 ELECTROLYTIC, 50 1UF M
C413 24214821 CERAMIC DISC, 500 B 820PF K
C416 24678229 ELECTROLYTIC, 200 2.2UF M 3A
C417 24214391 CERAMIC DISC, 500 B 390PF K
C420 24794101 ELECTROLYTIC, 16 100UF M
C421 24794221 ELECTROIYTIC, 16 220UF M
C423 24797479 ELECTROLYTIC, 50 4.7UF M
C430 24212102 CERAMIC DISC, 50 B 1000PF K
C431 24763222 ELECTROLYTIC CE04G 16 2200UF M
C433 24073034 ELECTROLYTIC CE04P 16 10UF M 3A
C436 24793102 ELECTROLYTIC, 10 1000UF M
C438 24667102 ELECTROLYTIC CE04Q 25 1000UF M 3A
C440 24082938 PLASTIC FILM, 1500 H 2200PF H
C441 24693472 PLASTIC FILM, 100 4700PF J
C442 24082917 PLASTIC FILM, 315 0.3UF J
C442 24082918 PLASTIC FILM, 315 0.33UF J
C443 24082956 PLASTIC FILM, 1500 H 7200PF H
C444 24082946 PLASTIC FILM, 1500 H 4700PF H
C445 24828563 PLASTIC FILM, 200 56000PF J
C446 24829473 PLASTIC FILM, 400 47000PF J
C447 24679220 ELECTROLYTIC, 250 22UF M 3A
C448 24640908 ELECTROLYTIC, 160 33UF M 3A LI
C449 24214331 CERAMIC DISK CK45 B 500 330PF K
C451 24591823 PLASTIC FILM, 50 0.082MF J
C460 24591682 PLASTIC FILM, 50 6800PF J
C461 24082917 PLASTIC FILM, 315 0.3UF J
C463 24212222 CERAMIC DISK CK45 B 50 2200PF K
C464 24640872 ELECTROLYTIC CE04R 100 10UF M 3A
C467 24820333 PLASTIC FILM, 630 33000PF J
C470 24794470 ELECTORLYTIC, 16 47UF M
C472 24539474 MT PLA CAP M 50 474J MUL
C473 24073081 ELECTROLYTIC, 50 1.OUF M 3A
C482 24539154 MT PLA CAP M 50 154J MUL
C498 24591272 PLASTIC FILM, 50 2700PF J
C499 24591104 PLASTIC FILM, 50 0.1UF J
C502 24092398 CERAMIC DISC, 25 0.1UF Z, 24092398A
NI TOOITSU
WARNING: BEFORE SERVICING THIS CHASSIS, READ THE “X-RAY RADIATION PRECAUTION”, “SAFETY
PRECAUTION” AND “PRODUCT SAFETY NOTICE” ON PAGE 3 OF THIS MANUAL.
CAUTION: The international hazard symbols “ ” in the schematic diagram and the parts list designate components
which have special characteristics important for safety and should be replaced only with types identical to those in the
original circuit or specified in the parts list. The mounting position of replacements is to be identical with originals.
Before replacing any of these components, read carefully the PRODUCT SAFETY NOTICE. Do not degrade the
safety of the receiver through improper servicing.
NOTICE:
• The part number must be used when ordering parts, in order to assist in processing, be sure to include the Model
number and Description.
• The PC board assembly with *mark is no longer available after the end of the production.
Model : 25AF6SH
Capacitors ............. CD : Ceramic Disk PF : Plastic Film EL : Electrolytic
Resistors ............... CF : Carbon Film CC : Carbon Composition MF : Metal Film
OMF : Oxide Metal Film VR : Variable Resistor FR : Fusible Resistor
(All CD and PF capacitors are ±5%, 50V and all resistors, ±5%, 1/6W unless otherwise noted.)
CHASSIS AND CABINET REPLACEMENT PARTS LIST

–20 –
SPECIFIC INFORMATIONS
LocationLocation
LocationLocation
Location Parts No.Parts No.
Parts No.Parts No.
Parts No. DescriptionDescription
DescriptionDescription
Description
No.No.
No.No.
No.
LocationLocation
LocationLocation
Location Parts No.Parts No.
Parts No.Parts No.
Parts No. DescriptionDescription
DescriptionDescription
Description
No.No.
No.No.
No.
C503 24092398 CERAMIC DISC, 25 0.1UF Z, 24092398A
NI TOOITSU
C512 24212222 CERAMIC DISK CK45 B 50 2200PF K
C517 24797101 ELECTROLYTIC CE04G 50 100UF M
C521 24092398 CERAMIC DISC, 25 0.1UF Z, 24092398A
NI TOOITSU
C522 24092398 CERAMIC DISC, 25 0.1UF Z, 24092398A
NI TOOITSU
C523 24092398 CERAMIC DISC, 25 0.1UF Z, 24092398A
NI TOOITSU
C524 24794101 ELECTROLYTIC, 16 100UF M
C526 24590222 PLASTIC FILM, 50 2200PF J
C527 24353100 CERAMIC DISC CC45CH 50 CH 10PF C
C528 24073078 ELECTROLYTIC CE04P 50 0.22UF M 3A
C610 24794100 ELECTROLYTIC, 16 10UF M
C612 24794470 ELECTORLYTIC, 16 47UF M
C621 24797100 ELECTROLYTIC, 50 10UF M
C622 24797100 ELECTROLYTIC, 50 10UF M
C624 24797478 ELECTROLYTIC, 50 0.47UF M
C661 24590102 PLASTIC FILM, 50 1000PF J
C662 24590102 PLASTIC FILM, 50 1000PF J
C663 24794100 ELECTROLYTIC, 16 10UF M
C673 24669479 ELECTROLYTIC, 50 4.7UF M 3A
C676 24539104 PLASTIC FILM, 50 0.1UF J
C677 24539104 PLASTIC FILM, 50 0.1UF J
C678 24669479 ELECTROLYTIC, 50 4.7UF M 3A
C681 24668102 ELECTROLYTIC, 35 1000UF M 3A
C682 24669221 ELECTROLYTIC CE04Q 50 220UF M 3A
C683 24668102 ELECTROLYTIC, 35 1000UF M 3A
C690 24669101 ELECTROLYTIC, 50 100UF M 3A
C704 24591822 PLASTIC FILM, 50 8200PF J
C707 24795470 ELECTROLYTIC, 25 47UF M
C712 24795470 ELECTROLYTIC, 25 47UF M
C713 24709100 ELECTROLYTIC, 200 10UF M
C714 24436101 CERAMIC DISC CC45 SL 50 100PF J
C715 24214472 CERAMIC DISK CK45 B 500 4700PF K
C716 24436101 CERAMIC DISC CC45 SL 50 100PF J
C717 24214472 CERAMIC DISK CK45 B 500 4700PF K
C718 24794470 ELECTORLYTIC, 16 47UF M
C719 24435560 CERAMIC DISC, 500 SL 56PF J
C720 24709100 ELECTROLYTIC, 200 10UF M
C721 24794470 ELECTORLYTIC, 16 47UF M
C722 24436561 CERAMIC DISC, 50 SL 560PF J
C726 24212102 CERAMIC DISC, 50 B 1000PF K
* C801 24503002 MT PLA AC275 0.22UF M
* C802 24503002 MT PLA AC275 0.22UF M
* C805 24092281 CERAMIC DISC, AC250 E 4700PF
* C806 24092281 CERAMIC DISC, AC250 E 4700PF
C808 24667101 ELECTROLYTIC, 25 100UF M 3A
C809 24539474 MT PLA CAP M 50 474J MUL
C810 24086934 ELECTROLYTIC, 450 560UF M 35F
C811 24092565 CERAMIC DISC, AC250 B 470PF K
* C813 24092565 CERAMIC DISC, AC250 B 470PF K
* C814 24092565 CERAMIC DISC, AC250 B 470PF K
C816 24794470 ELECTORLYTIC, 16 47UF M
C817 24092339 CERAMIC DISC, 2K 330PF K
C818 24095931 PLASTIC FILM CF92T 1250 H 2200PF J
C819 24676220 ELECTROLYTIC, 100 22UF M 3A
C821 24214471 CERAMIC DISC, 500 B 470PF K
C822 24539474 MT PLA CAP M 50 474J MUL
C823 24214471 CERAMIC DISC, 500 B 470PF K
C826 24539104 PLASTIC FILM, 50 0.1UF J
C829 24212391 CERAMIC DISC, 50 B 390PF K
C831 24794470 ELECTORLYTIC, 16 47UF M
C833 24797229 ELECTROLYTIC, 50 2.2UF M
C841 24797100 ELECTROLYTIC, 50 10UF M
C842 24794100 ELECTROLYTIC, 16 10UF M
C843 24539104 PLASTIC FILM, 50 0.1UF J
C884 24086916 ELECTROLYTIC CE692R 160 330UF M 3D
C885 24214471 CERAMIC DISC, 500 B 470PF K
C887 24214471 CERAMIC DISC, 500 B 470PF K
C889 24669222 ELECTROLYTIC, 50 2200UF M 3A
C893 24092337 CERAMIC DISC, 2K 220PF K
C895 24676470 ELECTROLYTIC, 100 47UF M 3A
C898 24539224 PLASTIC FILM, 50 0.22 UF J
C902 24092353 CERAMIC DISC, 2K 4700PF K
C903 24436121 CERAMIC DISC, 50 SL 120PF J
C904 24436471 CERAMIC DISC, 50 SL 470PF J
C905 24436471 CERAMIC DISC, 50 SL 470PF J
C906 24436121 CERAMIC DISC, 50 SL 120PF J
C907 24436471 CERAMIC DISC, 50 SL 470PF J
C908 24436121 CERAMIC DISC, 50 SL 120PF J
C909 24679330 ELECTROLYTIC, 250 33UF M 3A
C910 24797478 ELECTROLYTIC, 50 0.47UF M
C911 24203100 ELECTORLYTIC, 16 10UF M 7L 3A
C912 24073042 ELECTROLYTIC, 16 1000UF M 3A
C913 24794220 ELECTROLYTIC, 16 22UF M
C914 24212103 CERAMIC DISC, 50 B 10000PF K
C930 24214101 CERAMIC DISC, 500 B 100PF K
C931 24214101 CERAMIC DISC, 500 B 100PF K
CA22 24473150 CERAMIC, 50 SL 15PF J
CA23 24473150 CERAMIC, 50 SL 15PF J
CA24 24473150 CERAMIC, 50 SL 15PF J
CA25 24473150 CERAMIC, 50 SL 15PF J
CA34 24474101 CERAMIC, 50 B 100PF K
CA37 24474101 CERAMIC, 50 B 100PF K
CA38 24474101 CERAMIC, 50 B 100PF K
CA42 24794100 ELECTROLYTIC, 16 10UF M
CA43 24539104 PLASTIC FILM, 50 0.1UF J
CA44 24539104 PLASTIC FILM, 50 0.1UF J
CA68 24794100 ELECTROLYTIC, 16 10UF M
CA70 24212472 CERAMIC DISK CK45 B 50 4700PF K
CA71 24212561 CERAMIC DISC, 50 B 560PF K
CA72 24794331 ELECTROLYTIC, 16 330UF M
CA73 24474181 CERAMIC CK141B 50 180PF K
CA74 24797010 ELECTROLYTIC, 50 1UF M
CA99 24539104 PLASTIC FILM, 50 0.1UF J
CB01 24763471 ELECTROLYTIC, 16 470UF M
CB20 24212101 CERAMIC DISC, 50 B 100PF K
CB21 24212221 CERAMIC DISC, 50 B 220PF K
CB22 24591272 PLASTIC FILM, 50 2700PF J
CS02 24085958 ELEC. NONPOLAR CE04J 50 1.0UF M NP
CS03 24085958 ELEC. NONPOLAR CE04J 50 1.0UF M NP
CS04 24797010 ELECTROLYTIC, 50 1UF M
CS05 24797010 ELECTROLYTIC, 50 1UF M
CS06 24797010 ELECTROLYTIC, 50 1UF M
CS07 24797010 ELECTROLYTIC, 50 1UF M
CS10 24794100 ELECTROLYTIC, 16 10UF M
CS11 24794100 ELECTROLYTIC, 16 10UF M
CS12 24797010 ELECTROLYTIC, 50 1UF M
CS13 24797010 ELECTROLYTIC, 50 1UF M
CS29 24203220 ELECTROLYTIC CE04WS 16 22UF M 7L 3A
C 01 24794101 ELECTROLYTIC, 16 100UF M
C 03 24073077 ELECTROLYTIC, 50 0.1UF M 3A
C 04 24797010 ELECTROLYTIC, 50 1UF M
C 05 24797220 ELECTROLYTIC, 50 22UF M
C 06 24567473 PLASTIC FILM, 50 47000PF J
C 19 24073077 ELECTROLYTIC, 50 0.1UF M 3A
C 20 24073077 ELECTROLYTIC, 50 0.1UF M 3A
C 22 24073077 ELECTROLYTIC, 50 0.1UF M 3A