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SERVICE MANUAL 

 

13

2. BLOCK DIAGRAM FOR SUPPLY VOLTAGE SYSTEM

 

 

Regulator

V115

N441

N442

Regulator

V871,

VD882

FBT

T400

VD491

+190V

VD451

+45V

VD461

+16V

VD471

To  CRT RGB PCB

To A100,N401

To N401

+8V

+5V-2

To A100

VD891

+115V

To N600

VD881 +15V-H

VD871  +15-S

+5V-1

                  To   H Out
                         EEPROM
                         R/C Input

+3.3V

            To N100

              Keyboard

Switch

Transformer

T804

Power Regulat ion

and Control Circuit

STR-G5653/F6654

Bridge Rectifying

Filter

VD803~VD806

C802,C807

Line Filter

L801,C801,

C802

1

5

0-2

5

0V~,50Hz

Feedback Circuit

N801

Error Signal

  

To A100,

    N100,

   N650

Fig

 

.5 Block Diagram for EX-1A1

 

  Supply Voltage System

Summary of Contents for 21C19/PF21C19

Page 1: ...FILE NO SM CTV O 099 COLOR TELEVISION SERVICE MANUAL MODEL NO 21C19 PF21C19 CHASSIS NO EX 1A1 Please read this manual carefully before service ...

Page 2: ...ENTS 4 CIRCUIT ADJUSTMENTS 7 STRUCTURE AND CHASSIS FUNCTION DESCRIPTION 12 STRUCTURE BLOCK DIAGRAM 12 BLOCK DIAGRAM FOR SUPPLY VOLTAGE SYSTEM 13 CHASSIS DESCRIPTION 14 SERVICE DATA 15 TECHNICAL DATA OF KEY ICS 15 WAVEFORMS OF KEY POINTS 33 SERVICE DATA OF KEY ICS 35 REPLACEMENT OF PARTS 39 APPENDIX 1 CIRCUIT DIAGRAMS 2 PRINTED CIRCUIT BOARD DIAGRAMS 3 FINAL WIRING DIAGRAMS 4 FINAL ASSEMBLY DIAGRAM...

Page 3: ...tage of the CRT anode So ensure that the maximum EHT voltage does not exceed the rated value after service and adjustment SAFETY PRECAUTION WARNING REFER SERVICING TO QUALIFIED SERVICE PERSONNEL ONLY 1 The TV has a nominal working EHT voltage Extreme caution should be exercised when working on the TV with the back removed 1 1 Do not attempt to service this TV if you are not conversant with the pre...

Page 4: ...omponents which have these special safety characteristics in this manual and its supplements are identified by the international hazard symbols on the circuit diagram and parts list Before replacing any of these components read the parts list in this manual carefully Substitute replacement components which do not have the same safety characteristics as specified in the parts list may create X ray ...

Page 5: ...aracteristics MAINTENANCE 1 Install the TV set on a stable and level surface Do not place the set near or over a radiator or heat register or where it is exposed to direct sunlight 2 Do not install the TV set in a place exposed to rain water excessive dust mechanical vibrations or impacts 3 Allow enough space at least 10cm between the TV and wall or enclosures for proper ventilation 4 Slots and op...

Page 6: ... set 1 3 Operate the TV for at least 15 minutes 1 4 Degauss the TV set using a specific degaussing coil 1 5 Set the brightness and contrast to maximum 1 6 Counter clockwise rotate the R B low brightness potentiometers to the end and rotate the green low brightness potentiometer to center 1 7 Receive green raster pattern signals 1 8 Loosen the clamp screw holding the deflection yoke assembly and sl...

Page 7: ...center of the screen 2 1 4 Turn both tabs at the same time keeping the angle constant to superimpose red and blue horizontal on the center of the screen 2 1 5 Adjust two tabs of the 6 pole magnet to superimpose red blue line and green line 2 1 6 Remember red and blue movement Repeat steps2 1 3 2 1 5 until optimal convergence is Deflection Coil Dummy Wedge Rubber Wedge Adhesive Deflection Yoke Puri...

Page 8: ...in better convergence in circumference 2 2 5 Fix the deflection yoke position and put the third wedge in either upper space Fasten the deflection yoke assembly on the picture tube 2 2 6 Detach the temporarily mounted wedge and put it in either upper space Fasten the deflection yoke assembly on the picture tube 2 2 7 After fastening the three wedges recheck overall convergence and ensure to get opt...

Page 9: ... voltage to the rated voltage 2 1 Make sure that the supply voltage is within the range of the rated value 2 2 Connect a digital voltmeter to the B voltage output terminal of the TV set Power on the TV and set the brightness and sub brightness to minimum 2 3 Regulate voltage adjustment components on the power PCB to make the voltmeter read 115 1V 3 High Voltage Inspection Caution No high voltage a...

Page 10: ...lume to 0 Then press and hold the MUTE button on the remote control and press the MENU button on the TV to enter the SERVICE mode In this case the S mode cannot be stored in the EEPROM To exit from the S mode turn off the TV set 6 1 2 After entering the S mode Red S is displayed on the upper center of the screen and MENU1 is default Use the POS buttons to highlight an adjustment and the VOL button...

Page 11: ...brightness delay time YDFN 07 NTSC brightness delay time YDFS 0F SECAM brightness delay time YDAV 0F AV brightness delay time TOP 18 UOC AGC VOL 21 UOC audio output amplitude IFFS 03 02 PIF 02 38 9MHz 03 38MHz HDOL 00 Cathode drive level AGC 03 IF ACG speed VG2B 3A VG2 brightness SBRI 1F Sub brightness MBRI 39 Max brightness SCON 20 Sub contrast MCON 3F Max contrast SCOL 32 Sub color OP1 BF Option...

Page 12: ...scription Default 0 OP_HOTEL HOTEL mode 1 1 OP_236 100 236 programs preset 0 2 OP_NTSC NTSC option set 1 3 OP_AV2 Two set of AV terminals 1 With AV2 0 Without AV2 1 4 OP_SVHS S Video terminal 1 5 OP_DVD DVD 1 6 OP_RGB RGB 1 RGB 0 No 0 OP1 7 OP_OSO Switch off in vertical overscan 0 0 OP_AVL AVL 1 1 OP_AUTO_SOUND Auto sound system test 1 2 OP_NOT_1 0 3 OP_NOT_2 0 4 OP_NOT_3 National Option Set OP_NO...

Page 13: ..._M Sound system M option set 1 0 OP_TUNER Tuner 1 Philips Tuner 0 Panasonic Tuner 0 1 OP_AUTO_LANG0 1 2 OP_AUTO_LANG1 0 3 OP_AUTO_LANG2 Auto language option set English Farsi Arabic Russian French German Indonesian Malay 0 4 OP_FORF 0 5 OP_FORS Field frequency options OP_FORS FORF 00 Auto60Hz 01 KeepLast 10 Force60Hz 11 Auto50Hz 0 6 OP_AVON If AV off then AV on 1 OP5 7 OP_ONPOSITION With HOTEL mod...

Page 14: ...AT24C08 Audio Prec essor TDA7449 H Drive V OUT TDA8356J Audio Amp lifier TDA7057AQ H OUT FBT T402 Power Supply Circuit STR F6654 or STR G5653 3 3V 5V 1 15V 115V CRT Audio Video Input Output Band 1 2 Vt AGC From Antenna IIC BUS Audio Input R L Speaker 150 250V 50Hz Fig 4 S t r u c t u r e B l o c k D i a g r a m f o r E X 1 A 1 C h a s s i s S e r i e s VY01 VY09 G R B Remote Remote Sensor HS0038 C...

Page 15: ...401 8V 5V 2 To A100 VD891 115V To N600 VD881 15V H VD871 15 S 5V 1 To H Out EEPROM R C Input 3 3V To N100 Keyboard Switch Transformer T804 Power Regulation and Control Circuit STR G5653 F6654 Bridge Rectifying Filter VD803 VD806 C802 C807 Line Filter L801 C801 C802 150 250V 50Hz Feedback Circuit N801 Error Signal To A100 N100 N650 Fig 5 Block Diagram for EX 1A1 Supply Voltage System ...

Page 16: ...nd advanced functions with fewer external components which provide much convenience for manufacturing and technical service 2 The EX 1A1chassis series mainly use the following ICs and assemblies Table 1 Key ICs and Assemblies Serial No Position Type Function Description 1 N100 TDA935X 6X 8X CH05T0102 Microcontroller and small signal processor UOC 2 N200 AT24C08 EEPROM 3 N650 TDA7449 Audio processo...

Page 17: ...d they are mounted in S DIP envelope with 64 pins The features are given in the following feature list The differences between the various ICs are given in the table on page 4 2 Features TV signal processor Multi standard vision IF circuit with alignment free PLL demodulator Internal switchable time constant for the IF AGC circuit A choice can be made between versions with mono intercarrier sound ...

Page 18: ...ecoder with embedded Controller TDA935X 6X 8X PS N2 series Controller 80C51 controller core standard instruction set and timing 1 s machine cycle 16 128Kx8 bit late programmed ROM 3 12Kx8 bit DATA RAM shared between Display Acquisition and Auxiliary Ram Interrupt controller for individual enable disable with two level priority Two 16 bit Timer Counter registers One 16 bit Timer with 8 bit Pre scal...

Page 19: ...s Soft colours using CLUT with 4096 colour palette Globally selectable scan lines per row 9 10 13 16 and character matrix 12x10 12x13 12x16 VxH Fringing Shadow selectable from N S E W direction Fringe colour selectable Meshing of defined area Contrast reduction of defined area Cursor Special Graphics Characters with two planes allowing four colours per character 32 software redefinable On Screen d...

Page 20: ...SERVICE MANUAL 18 3 Block Diagram Fig 6 Block Diagram for TDA935 6 8 PS N2 with Mono Intercarrier Sound Demodulator ...

Page 21: ...SERVICE MANUAL 19 Fig 7 Block Diagram for TDA935 6 8 PS N2 with QSS IF Sound Channel ...

Page 22: ...AVL EWD 1 20 Automatic Volume Levelling East West drive output VDRB 21 vertical drive B output VDRA 22 vertical drive A output IFIN1 23 IF input 1 IFIN2 24 IF input 2 IREF 25 reference current input VSC 26 vertical sawtooth capacitor TUNERAGC 27 tuner AGC output AUDEEM SIFIN1 1 28 audio deemphasis or SIF input 1 DECSDEM SIFIN2 1 29 decoupling sound demodulator or SIF input2 GND2 30 ground 2 for TV...

Page 23: ... demodulator QSS IF amplifier and East West output or not and on some software control bits The valid combinations are given in table 2 2 The vertical guard function can be controlled via pin 49 or pin 50 The selection is made by means of the IVG bit in subaddress 2BH Table 2 Pin functions for various versions IC version FM PLL Version QSS Version East West Y N N Y N Y CMB1 CM BO bits 00 01 10 11 ...

Page 24: ...SERVICE MANUAL 22 Fig 8 Pin Configuration SDIP 64 ...

Page 25: ...nnected to an independent input output Y0 and Y1 and the other side connected to a common input output Z With E LOW one of the two switches is selected low impedance ON state by Sn With E HIGH all switches are in the high impedance OFF state independent of SA to SC VDD and VSS are the supply voltage connections for the digital control inputs SA to SC and E The VDD to VSS range is 3 to 15V The anal...

Page 26: ...state the more positive voltage L LOW state the less positive voltage X STATE is immaterial Fig 21 Schematic Diagram One Switch Fig 11 Ratings Limiting values in accordance with the Absolute Maximum System IEC 134 Supply voltage with reference to VDD VEE 18 to 0 5 V Note To avoid drawing VDD current out of terminal Z when switch current flows into terminals Y the voltage drop across the bidireccti...

Page 27: ...otected on all pins 2 General Description The TDA7057AQ is a stereo BTL output amplifier with DC volume control The device is designed for use in TVs and monitiors but is also suitable for battery fed portable recorders and radios Missing Current Limiter MCL A MCL protection circuit is built in The MCL circuit is activated when the difference in current between the output terminal of each amplifie...

Page 28: ...m mode 2 General Description The TDA8356 is a power circuit for use in 90 and 110 colour deflection systems for field frequencies of 50 to 120 Hz The circuit provides a DC driven vertical deflection output circuit operating as a highly efficient class G system 3 Block Diagra 4 Pinning Fig 13 Fig 14 SYMBOL PIN DESCRIPTION Idrive pos 1 input power stage positive includes II sb signal bias Idrive neg...

Page 29: ...ol In 1 0dbsteps for balancefacility independent mute function All function are programmable via Serial bus 2 descripion The tda7449 is a volume tone bass and treble Balance left right processor for quality audio Applications in TV systems Selectable input gain is provided Control of all The functions is accomplished by serial bus The ac signal setting is obtained by resistor networks And switches...

Page 30: ...SERVICE MANUAL 28 4 Pin Connection Fig 16 5 Electrical Characteristics ...

Page 31: ...VS 9V RL 10KΩ RG 600Ω all controls flat G 0dB unless otherwise specified NOTE1 1 The device is functionally good at Vs 5V a step down on Vs to 4V does t reset the device 2 BASS and TREBLE response The center frequency and the response quality can be chosen by the external circuitry ...

Page 32: ...ration Two wire serial interface bus I2 C Bus compatible Filtered inputs for noise suppression with Schmitt trigger Clock frequency up to 400 kHz High programming flexibility Internal programming voltage Self timed programming cycle including erase Byte write and page write programming between 1 and 16 bytes Typical programming time 6ms 10ms for up to 16 bytes High reliability Endurance 106 cycles...

Page 33: ... units Cycle by cycle current limiting under voltage lockout with hysteresis over voltage protection and thermal shutdown protects the power supply during the normal overload and fault conditions Low current startup and a low power standby mode selected from the secondary circuit completes a comprehensive suite of features The series is provided in a five pin overmolded SIP style package affording...

Page 34: ...R F6654 Pin No Symbol Function Description 1 OCP FB Over current protection detection signal voltage limiting signal input 2 S MOSFET source 3 D MOSFET drain 4 VIN Supply voltage input for control circuit 5 GND Ground 4 Difference between STR G5653 and STR F6654 a Different size STR F6654 is larger b Different pin functions c Different electric characteristics Larger power output switching current...

Page 35: ...SERVICE MANUAL 33 3 WAVEFORMS OF KEY POINTS NI00 Pin58 NI00 Pin33 NI00 Pin34 NI00 Pin44 NI00 Pin22 NI00 Pin21 BU250 8DX B BSC60H HEAT ...

Page 36: ...SERVICE MANUAL 34 Notes The waveforms are only for reference The waveforms may differ dependent on different models BCT 4 Pin4 N100 P40 ...

Page 37: ...3 6 12 Pincushion input negative 0 13 Pincushion input positive 0 8 9 0 8 8 Table 4 Function and Service Data of TDA8356 N401 s Pins Digital Multimeter Victor DT890D Pin No Symbol Reference Voltage V Positive Resistance KΩ Nerative Resistance KΩ 1 Idrive pos 2 4 27 7 20 3 2 Idrive neg 2 4 27 7 20 4 3 VP 15 4 26 3 13 5 4 VO B 7 7 6 1 6 1 5 GND 0 0 0 6 VFB 45 0 113 3 13 7 7 VO A 7 5 6 1 6 1 8 VO gua...

Page 38: ...ive Resistance KΩ 1 CREF 4 0 28 2 21 9 2 VS 8 0 1 8 1 8 3 PGND 0 0 0 4 ROUT 3 3 9 4 9 3 5 LOUT 3 3 9 4 9 3 6 R_IN1 4 0 21 9 26 0 7 R_IN2 4 0 26 7 24 3 8 L_IN1 4 0 26 7 24 3 9 L_IN2 4 0 21 9 26 1 10 MUXOUT L 4 0 24 5 22 5 11 MUXOUT R 4 0 24 5 22 5 12 BIN R 4 0 28 0 26 1 13 BOUT R 4 0 28 0 21 0 14 BOUT L 4 0 28 0 20 8 15 TREBLE L 4 0 28 0 26 1 16 BIN L 4 0 30 5 28 0 17 TREBLE R 4 0 30 5 28 0 18 DIG_...

Page 39: ... 4 18 7 20 AVL EWD 1 0 01 27 6 21 2 21 VDRA 2 4 27 6 20 4 22 IFIN1 2 4 27 6 20 3 23 IFIN2 1 8 24 7 19 8 24 IREF 1 8 24 7 19 9 25 TUNERAGC 3 8 25 3 20 5 26 AUDEEM SIFIN1 1 3 8 27 7 21 5 27 DECSDEM SIFIN2 1 1 6 8 4 8 4 28 GND2 3 2 27 1 20 7 29 VSSA 2 3 27 8 21 6 30 SECPLL 0 0 0 31 SNDPLL SIFAGC 1 2 3 27 8 21 8 32 AVL SNDIF REF0 AMOUT 1 0 2 27 2 20 4 33 HOUT 0 4 5 3 5 3 34 FBISO 0 5 24 0 18 8 35 AUDE...

Page 40: ...2 5 27 6 20 8 50 BLKIN 6 0 27 9 21 3 51 RO 2 6 1 1 1 1 52 GO 2 5 1 1 1 1 53 BO 2 4 1 1 1 1 54 VDDA 3 2 11 0 11 3 55 VPE 0 0 0 56 VDDC 3 2 11 0 11 3 57 OSCGND 0 02 58 XTALIN 59 XTALOUT 60 RESET 0 0 0 61 VDDP 3 2 11 0 11 3 62 P1 0 INT1 0 63 P1 1 T0 1 5 3 3 3 3 64 P1 2 INT0 5 0 18 2 17 5 Notes The data are only for reference The data sheet may differ dependent on different models ...

Page 41: ...cteristics Components which have these special safety characteristics in this manual and its supplements are identified by the international hazard symbols or UL FCC FDA or VDE marking on the circuit diagram and parts list When replacing any of these components substitute the one which has the same safety characteristics as specified in the manual ...

Page 42: ...C I R C U I T D I A G R A M F O R 2 1 C 1 9 P F 2 1 C 1 9 ...

Page 43: ......

Page 44: ......

Page 45: ...MAIN PCB ...

Page 46: ...CRT RGB PCB ...

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