Toshiba 29A3DE Quick start guide

SCHEMATIC DIAGRAM MODEL : 29A3DE / 29A3E / 29A3SH
WARNING: BEFORE SERVICING THIS CHASSIS, READ THE "X-RAY RADIATION PRECAUTION", "SAFETY
PRECAUTION" AND "PRODUCT SAFETY NOTICE" ON THE MANUAL FOR THIS MODEL.
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 on the MANUAL for this
model. Do not degrade the safety of the receiver through improper servicing.
4. Voltages read with DIGITAL MULTI-METER from point indicated to chassing ground, using a color bar signal with all
controls at normal, line voltage 220 volts.
5. Waveforms are taken receiving color bar signal with enough sensitivity.
6. Voltage reading shown are nominal values and may vary ±20% except H.V.
NOTE:
1. RESISTOR Resistance is shown in ohm [K = 1.000, M = 1.000.000]. All resistors are 1/6W and 5%
tolerance carbon resistor, unless otherwise noted as the following marks.
1/2R = Metal or Metal oxide of 1/2 watt 1/2S = Carbon compsistion of 1/2 watt
1RF = Fuse resistor of 1 watt 10W = Cement of 10 watt
K = ±10% G = ±2% F = ±1%
2. CAPACITOR Unless otherwise noted in schematic, all capacitor values less than 1 are expressed in
?F, and the values more than 1 in pF.
All capacitors are ceramic 50V, unless otherwise noted as the following marks.
Electolytic capacitor Mylar capacitor
3. The parts indicated with " *" have special characteristics, and should be replaced with identical parts only.

–6 –
GENERAL ADJUSTMENTS
SPECIFIC INFORMATIONS
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
SPECIFIC INFORMATIONS
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 15)
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
SPECIFIC INFORMATIONS
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 cir-
cuit (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.





* The items marked with are not usable to display in the SELF DIAGNOSTIC FUNCTION for some model.

–9 –
GENERAL ADJUSTMENTS
SPECIFIC INFORMATIONS
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 15)
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”.