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SCHEMATIC DIAGRAM
MODEL : 21A3E / 21A3TR 21A3M / 21A3MJ
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.
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.
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.
SERVICE MODE
GENERAL ADJUSTMENTS
1. ENTERING TO SERVICE MODE 1) Press o button once on Remote Control. 2) Press o button again to keep pressing. 3) While pressing the o button, press MENU button on TV set.
Item Data S
(Service mode display)
2. DISPLAYING THE ADJUSTMENT MENU 1) Press MENU button on TV.
Service mode Press Press Adjustment mode Item S Data
SPECIFIC INFORMATIONS
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: Test signal selection : Selection of the adjustment items : Change of the data value : Adjustment menu mode ON/OFF : Initialization of the memory (QA02) : Reset the count of operating protect circuit to "00": "RCUT" selection : "GCUT" selection : "BCUT" selection : "CNTX" (or "SCNT") selection : "COLC" selection : "TNTC" selection : Test audio signal ON/OFF (1kHz) : Self diagnostic display ON/OFF : - / - - button (on Remote) or a button (on TV) a button (on Remote) Channel s/t (on TV or Remote) Volume ; +/ (on TV or Remote) MENU button (on TV) CALL + Channel button on TV (s) CALL + Channel button on TV (t) 1 button 2 button 3 button 4 button 5 button Color thickness correction 6 button note: Displayed differently as shown below, de8 button pending on the setting of the receiving color 9 button system. COLP (PAL) COLC (NTSC) COLS (SECAM)
CAUTION : Never try to perform initialization unless you have changed the memory IC.
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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 16) 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. I 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.
Signal off
NTSC signals (14 patterns) PAL signals (14 patterns)
Signals · Red raster · Green raster · Blue raster · All Black · All White · Black & White
Picture
· Black cross-bar · White cross-bar · Black cross-bar on green raster · Black cross-hatch · White cross-hatch
· Black cross-dot · White cross-dot
· H signal (white) · H signal (black)
*
The signals marked with
are not usable to display in the Test signal for some model.
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SPECIFIC INFORMATIONS
GENERAL ADJUSTMENTS
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. 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 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.
23****** POWER BUS LINE BUS CONT BLOCK
: : : :
00 OK OK UV V1 V2 QV01
Part number of microcomputer (QA01) Operation number of protecting circuit ----"00" is normal. 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)
SPECIFIC INFORMATIONS
*
The items marked with
are not usable to display in the SELF DIAGNOSTIC FUNCTION for some model.
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