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Toshiba CF35E50, Technical Training Manual

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Toshiba CF35E50 Technical Training Manual Download Page 83

83

first.

7. OVER CURRENT PROTECTION

CIRCUIT

1. Outline

 If main power (125V) current increases abnormally due to
components failure, there is possible danger of the  secondary
damage like failure getting involved in other part failure, and
abnormal heating.  To prevent this, over current protection
circuit is equipped, which detects current of main B line to
turn off power relay in abnormal situation.

2. Operation

Fig. 11-19 shows over current protection circuit.  When the
current of main B line increases abnormally due to the
shortage in load of main B line, voltage drop arises across
R470. By this voltage drop, when base-emitter  voltage of Tr
8 in protector module (Z801) becomes appprox. 0.7V or
more, Tr 8 turns on, and the voltage by divided ratio of R15
and R16 is applied to cathode of ZD4. When this voltage
becomes higher than zener voltage of ZD4, ZD4 turns on to
supply base current to base of Tr 6 via R14. This causes Tr
5 ON and voltage at pin 16 of Z801 becomes Low.  Therefore,
QB30 and Q843 turns off to set SR81 OFF.  Tr 6 and Tr 7 in
Z801 are in thyristor- connection, and power 5V-1 supplied
at pin 15 keeps protection operation for standby power until
main power switch is turned off.  During circuit operation,
power LED near main power switch blinks in red. Caution :

Fig. 11-19 Over current protection circuit

Z801
PROTECTOR MODULE

16

15

17

2

1

5V

MICON
QA01#7

RELAY
SR81

Q843

R830

Q830

MAIN B

R470

F470

To T461

R479

R472

C472

R16

R15

R14

R12

R11

R9

R10

ZD4

C1

Tr6

Tr5

Tr7

Tr8

Z801
PROTECTION MODULE

Summary of Contents for CF35E50

Page 1: ...COLOR TELEVISION CN27E90 CX32E70 CN32E90 CN35E15 CF35E50 CX35E60 CX35E70 CX35E81 CN35E90 CN35E95 TECHNICAL TRAINING MANUAL N5SS TG 1 C CHASSIS NTDCTV05 PRINTED IN JAPAN Aug 1995 So ...

Page 2: ... TUNER 18 3 IF MTS S PRO MODULE 19 4 PIP TUNER 23 SECTION III CHANNEL SELECTION CIRCUIT 24 1 OUTLINE OF CHANNEL SELECTION CIRCUIT SYSTEM 25 2 OPERATION OF CHANNEL SELECTION CIRCUIT 25 3 MICROCOMPUTER 26 4 MICROCOMPUTER TERMINAL FUNCTION 27 5 EEPROM QA02 29 6 ON SCREEN FUNCTION 29 7 SYSTEM BLOCK DIAGRAM 30 8 LOCAL KEY DETECTION METHOD 31 9 REMOTE CONTROL CODE ASSIGNMENT 32 10 ENTERING TO SERVICE MO...

Page 3: ...T OF BUS CONTROL OF PARAMETER FOR PICTURE CONTROLS 53 3 EMPLOYMENT OF CONTAINING EACH VIDEO BAND FILTER INSIDE 53 4 EMPLOYMENT OF CONTAINING EACH FILTER FOR S H INSIDE 53 5 LOW COST OF IC 53 SECTION VIII PIP MODULE 55 SECTION IX SYNC SEPARATION H AFC H OSCILLATOR CIRCUITS 58 1 SYNC SEPARATION CIRCUIT 59 2 H AFC Automatic Frequency Control CIRCUIT 60 3 H OSCILLATOR CIRCUIT 61 SECTION X VERTICAL OUT...

Page 4: ...ION CIRCUIT Side DPC Circuit 85 1 DEFLECTION DISTORTION CORRECTION IC TA8859P 86 2 SIDE DPC 87 3 DIODE MODULATOR CIRCUIT 88 4 ACTUAL CIRCUIT 89 SECTION XIII CLOSED CAPTION EDS CIRCUIT 92 1 OUTLINE 93 2 DATA TRANSMISSION FORMAT 93 3 DISPLAY FORMAT 94 4 CIRCUIT OPERATION 95 SECTION XIV POWER CIRCUIT 98 1 OUTLINE 99 2 RECTIFYING CIRCUIT AND STANDBY POWER SUPPLY 100 3 MAIN SUPPLY CIRCUIT 100 4 OUTLINE...

Page 5: ...LTER 119 12 DOLBY NR CIRCUIT 120 13 DSP FRONT ADDITION CIRCUIT 121 14 BUS CONVERTER 122 15 NEUTRAL BIAS 122 16 AUDIO OUTPUT AMPLIFIER For Rear SP 123 17 TROUBLESHOOTING CHART 124 SECTION XVI FAILURE DIAGNOSIS PROCEDURES 125 1 H STARTING CIRCUIT FAILURE DIAGNOSIS PROCEDURES 126 2 DEFLECTION CIRCUIT FAILURE DIAGNOSIS PROCEDURES 127 3 LEFT RIGHT PIN CUSHION DISTORTION CORRECTION CIRCUIT 128 4 X RAY P...

Page 6: ...6 SECTION I OUTLINE ...

Page 7: ...P unit 6 C C EDS R G B SW 3 MAJOR SPECIFICATIONS NEW FUNCTIONS IN ADDITION TO THOSE OF N5SS 1 EOS Extended Data Service 2 Center Ch Audio Input provided 4 MODIFICATIONS ON CHASSIS 1 Serviceabilityimprovedwithdirect frontaccesssystem employed 2 One touch cabinet securing CN32E90 to the chassis 3 Improved serviceability with the bus control system employed for the defection circuits 4 Improved servi...

Page 8: ...OF CHASSIS REAR AMP circuit CONVERTER trans POWER DEF circuit H OUT H OUT trans DPC circuit V OUT RF SW A V circuit CRT circuit PIP circuit CCD circuit DPC circuit EDS RGB SW circuit AUDIO OUT IF MTS A PRO module SIGNAL circuit ...

Page 9: ...sult the corresponding page numbers in brackets Fig 1 2 POWER Front View Press to open the door Behind the door VIDEO AUDIO IN jacks VIDEO 3 DEMO button MENU button CHANNEL buttons VOLUME buttons buttons ANT VIDEO button ADV button POWER indicator POWER button Remote sensor ...

Page 10: ... terminals EXTernal SPEAKER terminals MAIN SPEAKER switch REAR SPEAKER terminals S VIDEO IN jack VIDEO 1 VARiable AUDIO OUT jacks VIDEO AUDIO OUT jacks PIP AUDIO OUT jacks VIDEO AUDIO IN jacks VIDEO 2 VIDEO AUDIO IN jacks VIDEO 1 ...

Page 11: ...UX switch Set to TV to control the TV TV VIDEO Channel Number buttons PIP function buttons AUDio button PICture button RESET button ANT 1 2 button C CAPT button CYS SBS button Learning buttons You can use these eight buttons only as Learning function buttons They are not affected by Mode selection TV CABLE VCR AUX To operate buttons inside the cover slide the cover down and toward you TIMER button...

Page 12: ...VIDEO AUDIO OUT Jacks provide fixed level audio and video outputs from whatever is displayed on the screen VARIABLE AUDIO OUT Jacks feed volume controlled stereo audio out from whatever is displayed on the screen allows connectionofaudioamplifierandletsyouadjust sound level with TV s remote PIP AUDIO OUT Jacks provide fixed level audio outputs from whatever is displayed on the PIP window screen EX...

Page 13: ...13 7 CN32D90 BLOCK DIAGRAM ...

Page 14: ...3W 10Wx2 10Wx2 10Wx2 10Wx2 13W 5Wx2 17 Speaker Size Nbr 80x120x2 70x130x2 80x120x2 70x130x2 70x30x2 100R Hon 100R REAR 18 Comb Filter GLS CCD CCD CCD GLS 19 Dy Quadruple Focus 20 Scan Velocity Modu 21 Vert Contour Corre 22 Black Level Expand 23 Flesh Tone Correct 24 Dynamic Noise Reduc 25 Picture Preference 26 Horiz Resolution 650 700 700 800 800 27 Parental Ch Lock 28 Channel Label 32ch 29 3 Lang...

Page 15: ...17 Speaker Size Nbr 70x130x2 70x130x2 70x130x2 80x120x2 80x120x2 100R REAR 120R REAR 18 Comb Filter DIG DIG DIG DIG DIG 19 Dy Quadruple Focus 20 Scan Velocity Modu 21 Vert Contour Corre 22 Black Level Expand 23 Flesh Tone Correct 24 Dynamic Noise Reduc 25 Picture Preference 26 Horiz Resolution 800 800 800 800 800 27 Parental Ch Lock 28 Channel Label 32ch 29 3 Language Display 30 Clock Off Timer 31...

Page 16: ...16 SECTION II TUNER IF MTS S PRO MODULE ...

Page 17: ...2 As the tuner EL466L that which contains an integrated PLL circuit is employed 3 Wide band double SAW filter F1802R used 4 FS frequencysynthesizer typechannelselectionsystem employed 5 VIF SIF circuit uses PLL sync detection system to improve performances shown below Telop buzz in video over modulation DP DG characteristics video high fidelity reproduction Cross color characteristic coloring phen...

Page 18: ...T IF outputs P 45 75 MHz C 42 17 MHz S 41 25 MHz BM Tuner power supply 9V RF AGC Gain control terminal to obtain constant IF output VT Control voltage to select channels 2 2 3 Tuner VT Voltage unit V 1 VHF 2 UHF CH VT voltage TYP 2 1 4 6 6 4 A 2 12 8 B 20 0 C 1 4 I 3 5 10 5 6 J 7 6 N 9 7 R 11 8 W 14 2 FF 17 9 LL 24 2 CH VT voltage TYP MM 1 1 QQ 2 2 WW 4 0 14 5 8 20 7 8 26 9 2 32 10 8 38 12 5 44 13...

Page 19: ...ng PLL lock speed Next whenavideooutexists theinternalresistanceisshort circuited and the APC filter consists of C022 and C053 internal resistance and R018 As a result the filter effect increases and the PLL lock speed decreases Consequently undernormalsignalreception phaseofthedetectorswitching carrier is locked in a stable condition if an IF video carrier is lostforashorttimeduetoovermodulation ...

Page 20: ... R F A G C A F C V I D E O O U T A D R S W M Z003 4 5MHz SIF SIGNAL FM DET COIL L053 15 11 12 9 7 5 4 2 1 14 22 13 16 20 21 23 18 17 S I F L I M I T FM DET S I F D E T A P C V C D IF A M P A G C V I D E O D E T L051 VCO C W C O I L R 1 5 1 TO SOUND M P X I C L502 AFT COIL R 0 2 1 TP12 Q 0 0 4 Z002 R 0 2 2 R F A G C R 0 5 1 1 2 3 4 5 6 7 8 9 LOCK CONTROL 15dB 6dB R018 C022 C053 C106 ...

Page 21: ...rix The audio signals obtained by demodulating the sound multiplexsignaldevelopatpin10and11ofHICanddevelop the terminals of 12 and 14 of the module Fig 2 5 Block diagram of MVUS32S Note Of the mode selection voltages switching voltages for STE SAP MONO do not output outside the module They are used inside the module to control the BUS Table 2 1 Matrix for broadcasting conditions and reception mode...

Page 22: ...from a microcomputer Fig 2 6 shows a block diagram of the A PRO IC Fig 2 6 A PRO block diagram TA1217N Lin Rin Cin Win SDA SGL TONE CONTROL LPF Center LEVEL Woofer LEVEL VOLUME BALANCE I C 2 D A CONV I O Lout Rout Cout Wout SAP det STE det R in C in L in SCL SDA W out O out L out R out From From From A V Dolby A V Q670 Q640 Q670 Q670 9V 16 17 18 19 20 21 22 23 24 25 26 27 Via QS101 4 5 6 7 31 24 2...

Page 23: ...grated into one unit The tuner receives RF signals induced on an antenna and develops an AFT output video output and audio output The tuner has receive channels of 181 as in the tuner for the main screen and it is also controlled through the I2C bus As the IC for the IF a PLL complete sync detection plus audio inter carrier system are employed TUNER SECTION SAW FILTER VIF SIF CIRCUIT RF AGC AFT OU...

Page 24: ...24 SECTION III CHANNEL SELECTION CIRCUIT ...

Page 25: ...lselectionornosignal reception 2 CONTROL OF VIDEO CHROMA DEF SIGNAL PROCESS IC Q501 Toshiba TA1222N Adjustments for uni color brightness tint color gain sharpness and PIP uni color Setting of adjustment memory values for sub brightness sub color and sub tint etc Setting of memory values for video parameters suchaswhitebalance RGBcutoff GBdrive and gcorrection etc Setting of video parameters of vid...

Page 26: ... 1 LED uses big current port for output only For clock oscillation 8MHz ceramic oscillator is used I2C has two channels One is for EPROM only SelfdiagnosisfunctionwhichutilizesACKfunctionof I2C is equipped Function indication is added to service mode Remote control operation is equipped and the control by set no touch is possible Bus connector in the conventional bus chassis is deleted Substantial...

Page 27: ...E SP MUTE NC POWER LED NC NC SCL0 SDA0 SYNC VCD NC AFT2 AFT1 KEY A KEY B SGV SGA GND GND P40 PWM0 P41 PWM1 P42 PWM2 P43 PWM3 P44 PWM4 P45 PWM5 P46 PWM6 P47 PWM7 P50 PWM8 TC2 P51 SCL1 P52 SDA1 P53 AINO TC1 P54 AIN1 P55 AIN2 P56 AIN3 P60 AIN4 P61 AIN5 P62 P63 VSS VDD P57 P32 P57 SDA0 SCL0 TC3 P31 RXIN P30 P20 RESET XOUT XIN TEST 0SC2 0SC1 VD HD Y BL B G R VDD ACP NC GND SDA1 SCL1 SYNC AV1 RMT IN SW ...

Page 28: ...ection 0 to 5V 19 SGV TEST SIGNAL OUT Out Test signal output In normal L 0V 20 SGA TEST AUDIO OUT Out Test audio output In normal L 0V 21 VSS POWER GROUNDING 0V Gounding voltage 0V 22 R R Out At display on Pulse 23 G G Out At dispaly on Pulse 24 B B Out At dispaly on Pulse 25 Y BL BL Out At dispaly on Pulse 26 HSYNC In HSYNC for OSD display Pulse 27 VSYNC In VSYNC for OSD display Pulse 28 OSC1 DIS...

Page 29: ... is shown in Figure 3 3 Fig 3 3 6 ON SCREEN FUNCTION ON SCREEN FUNCTION indicates data like channel volume Formerly exclusive use of OSD IC was used but in N5SS OSDfunctionisinvolvedinmicrocomputer Pinfunctionconcerningon screenisshowninfigure3 4 OscillationclockofOSD isapprox 4 5MHz 9MHzwhichbecomestwiceinmicrocomputerisdotclock Foroscillationcoil TRF1160D LA02 isused Fig 3 4 1 2 3 4 8 7 6 5 A0 A...

Page 30: ...SWITCH REMOTE SENSOR UNIT MAIN U V TUNER EL446L H001 SDA SCL HY01 SUB U V TUNER EL922L SDA SCL SDA SCL SDA SCL VCD TA1222 Q501 H002 IF MPX MVUS345 27 28 21 20 SDA SCL QV01 AV SW TA1219N 26 27 QM01 DSP SDA SCL 6 1MHz CLOCK SIGNAL OUTPUT 8MHz CLOCK SYNC DET AFT DET SYNC DET AFT DET MAIN SCREEN SUB SCREEN MEMORY 24LC04B1 P SDA SCL 5 6 H SYNC PULSE VSYNC PULSE REMOTE CONTROL OUTPUT SOUND MUTE SPEAKER ...

Page 31: ...rcuit Ascan be seen from the diagram when one of key among SA 01 to SA 08 is pressed each of two input terminal pins 17 18 developes avoltageVincorrespondingtothekeypressed Thevoltage measurement and key identification arecarriedoutbyanA Dconverterinsidethemicrocomputer and the software Fig 3 6 Local key assignment Key No Function Key No Function SA 02 POWER SA 01 DEMO START STOP SA 03 CH UP SA 04...

Page 32: ... PIP LOCATE 42H PIP LOCATE 43H PIP LOCATE 44H CARVER 45H SURROUND UP 46H SURROUND DOWN 47H VOCAL ZOOM 48H CHANNEL LOCK 49H 4AH PIP CHANNEL UP 4BH PIPCHANNELDOWN 4CH PIPSTILL RELEASE 4DH PIP ZOOM ZOOM SIZE 4EH PIP LOCATE 4FH PIP SOURCE Custom codes are 40 BFH Code Applicable Applicable Conti Function to remote to TV set nuty control 50H PIP STILL 51H PIP ON OFF 52H Do not use Old type core power ON...

Page 33: ...E SERVICE B1H DSP ON OFF B2H TEXT 1 B3H TV PIP VIDEO CHANGE OVER B4H CAPTION 1 B5H B6H B7H TV CABLECHANGE OVERINSAMETIMEONMANANDSUB B8H HOTEL SETTING MENU B9H DATA 4 TIMES SPEED UP BAH DATA 4 TIMES SPEED DOWN BBH CHANGE OVER OF HOTEL NORMAL BCH PIP CENTER BDH M MODE BEH CAPTON OFF BFH ALL CHANNEL PRESET Custom codes are 40 BFH Code Applicable Applicable Conti Function to remote to TV set nuty cont...

Page 34: ... VERTICALM CURVECORRECTION VSC FVC E2H E3H E4H E5H E6H E7H E8H E9H EAH HORIZONTALWIDTH WID PARA EBH TRAPEZOIDE CORRECTION TRAP ECH TEST TONE EDH DOLBY EEH 3 DIMENTIONAL Y C SEPARATION EFH DPC E0H STANDARD HEIGHTLINEARITY VLIN HIT E1H WIDE HEIGHT LINEARITY VLIN F2H SCROOL F3H WIDE 1 2 3 F4H F5H F6H F7H F8H F9H FAH FBH FCH FDH FEH FFH ...

Page 35: ...9 Black cross hatch 10 White cross hatch 11 White cross dot 12 Black cross dot 13 H signal bright area 14 H signal dark area 15 Black cross G 3 SGA audio test signal output should be square wave of 1kHz 12 SERVICE ADJUSTMENT 1 ADJUSTMENT MENU INDICATION ON OFF MENU key on TV set 2 During display of adjustment menu the followings are effective a Selection of adjustment item POS UP DN key on TV remo...

Page 36: ...al operation Countermeasure in case that phenomenon always arises B Detection of shortage in BUS line Example of screen display C Check of comunication status in BUS line D Check of signal line by sync signal detection E Indication of part code of microcom QA01 F Number of operation of power protection circuit SELF CHECK No 2390XXXX Part code of QA01 POWER 000000 Number of operation of power prote...

Page 37: ...f self diagnosis is displayed on screen Besides when 9 key on remote unit is pressed diagnosis operation is first executed once Clearing method of self diagnosis result In the error count state of screen press CHANNEL DOWN button on TV set pressing DISPLAY button on remote unit CAUTION All ways keep the following caution in the state of service mode screen Do not press CHANNEL UP button This will ...

Page 38: ...f voltage at pin 7 of QA01 DC 5V 8MHz oscillation waveform at pin 32 of QA01 Pulse output at pins 37 and 38 of QA01 Check relay driving circuit Check power circuit Check OSC circuit Replace QA01 Voltage check at pin 32 of QA01 DC 5V Check reset circuit Replace QA01 YES NG NG NG NG OK NO OK OK OK ...

Page 39: ... at pins 17 18 of QA01 5V to 0V Replace QA01 Check key in circuit NG OK NG OK Remote unit key Pulse input at pin 35 of QA01 When remote unit key is pressed Replace QA01 Check tuner power circuit NG OK No picture Voltage at pins of 5V and 32V Check H001 Check tuner power circuit ...

Page 40: ...eplace QA02 Adjust items of TV set adjustment Note Use replacement parts for QA02 Check power circuit Check QA01 NG NG OK OK OK No indication on screen Check of character signal at pin 23 of QA01 5VP P Input of OSC waveform at pin 29 of QA01 with indication key pressed Check of sync signal at pins 26 27 of QA01 Replace QA01 Check V C D circuit Check OSC circuit Check sync circuit ...

Page 41: ...41 SECTION IV AUDIO OUTPUT CIRCUIT ...

Page 42: ... R L R VIDEO 1 VIDEO 2 VIDEO 3 FOR PIP IF MODULE AUDIO L R PIP OUT AUDIO R L R L R L R L R L DSP CIRCUIT VIF MTS A PRO MODULE R L R L W Q670 R L W 12 14 EQ ER AS AR AI AJ 6 7 11 13 3 9 15 17 29 31 2 1 35 37 16 18 25 24 22 2 4 1 12 2 11 MOTHER TV CHILD TV VIDEO 1 VIDEO 2 VIDEO 3 FRONT INPUT VARIABLE AUDIO OUTPUT TERMINAL VIDEO OUTPUT TERMINAL R out L out W out ...

Page 43: ...uput IC In the TA8256H one channel is added and a total of 3 channels can be used but performance for each channel is the same as that of the TA8218H Fig 4 2 shows a block diagram of the IC Fig 4 2 AMP 2 AMP 3 AMP 1 1 11 7 5 12 10 8 4 3 2 47m F 1m F 47m F 1m F R R 1m F W W 6 9 RIPPLE FILTER Vcc 4k 30k 350W PRE GND 350W 4k 30k 30k 4k 350W 20kW MUTING OUTPUT 3 S or W OUTPUT 3 OUTPUT 2 POW GND R Vcc ...

Page 44: ...44 SECTION V A V SWITCHING CIRCUIT ...

Page 45: ...V SW IC TA1218N QV01 and selects signals from U V tuner Main U V tuner Sub E1 E2 and E3 3 1 COMPOSITE VIDEO SIGNAL The selected video signal is output to pin 38 of QV01 and separated by comb filter into Y and C The resulted signal is input to pins 30 and 32 of QV01 and is output to pins 36 and 34 to be supplied to Q501 V C D Video signal for sub picture is output to pin 42 of QV01 and is supplied ...

Page 46: ...V in Y in C in Q501 Y out C out V in COMB FILTER SYNC in QA01 L R in DSP 18 17 16 15 14 13 12 11 10 9 8 7 6 5 2 1 26 28 29 30 31 32 34 35 36 37 38 42 C in R in S in L in C in R in S in L in V in R in L in V in R in L in PIP R out PIP L out SYNC OUT PIP TV in PIP L in Y in PIP R in C out R out Y out L out H out PIP V out C in ...

Page 47: ...47 SECTION VI VIDEO PROCESSING CIRCUIT ...

Page 48: ...2 3 The signal is processed on luminance and chroma signals andisconvertedtooriginalcolorsignal R G B by RGB matrix Next the signal is superimposed with OSD signal to be output to pins 41 42 and 43 and is supplied to CRT Drive circuit 4 The signal for Scan Modulation is processed with differential in Q501 to be output to pin 48 Besides at terminal for adjustment TP501 luminance and chroma signalsa...

Page 49: ...GND Grounding terminal of chroma circuit 15 Y1 INPUT Luminance signal input terminal 32 PIP Ys Input terminal for switching pulse signal of PIP signal 33 PIP B Input terminal of PIP RGB signal 34 PIP G Ditto 35 PIP R Ditto 36 OSD Ys Input terminal for switching pulse signal of OSD signal 37 OSD B Input terminal for OSD RGB signal 38 OSD G Ditto 39 OSD R Ditto 40 Vcc 2 9V source terminal 41 B OUTPU...

Page 50: ...PUT CHROMA GND Y1 INPUT V SEP SYNC INPUT SYNC OUTPUT DEF GND AFC 1 32 x FH DEF Vcc 9V H OUT BENDING CORRECT AFC PULSE INPUT BLK INPUT DIGITAL GND SDA SCL DAC 2 2bit DAC 1 1bit MONITOR OUTPUT COLOR LIMITER Y2 INPUT Q INPUT I INPUT BLACK PEAK HOLD APL DET VSM OUTPUT Ym INPUT POWER OFF INPUT Vcc 3 ABL INPUT Y COLOR DIFFERENCE RGB GND R OUTPUT G OUTPUT B OUTPUT Vcc 2 9V R ANALOG OSD INPUT G ANALOG OSD...

Page 51: ...Y Y I Q VM COLOR DEMOD DELAY LINE SYNC DEF PROCESSING RGB MATRIX RGB SW VELOCITY MODULATION CRT DRIVE Q501 V C D H OUT VP TP501 OSD R G B Ys Ym 39 38 37 36 47 55 31 23 17 15 13 5 6 4 53 52 51 48 43 42 41 COLOR SIGNAL PROCESSING LUMINANCE SIGNAL PROCESSING Microcomputer OSD or EDS or C C ...

Page 52: ...52 SECTION VII V C D IC ...

Page 53: ...dulation processing circuit External Inside Fsc trap for chroma demodulation output External Inside 4 EMPLOYMENT OF CONTAINING EACH FILTER FOR S H INSIDE Circuit operation by extremely low current Employment of leak current cancel circuit Employment of detection circuit which does not suffer from influence of stray capacity Former TA8845N TA1222N Chroma ACC killer filter External Inside Y color di...

Page 54: ... OSD R IN 22 Ys IN 25 ABL IN RGB BRIGHT CLAMP CONTRAST YS SW CLAMP OSD AMP YS SW RGB MATRIX SW PEAK ACL DET ABCL AMP DRIVE CLAMP BLK RGB OUT CUT OFF 41 42 43 B OUT G OUT R OUT VCC 98 GND 46 44 47 Y M IN POWER OFF IN YM SW 30 HD OUT BLACK EXPAND MATRIX HD OUT EXT EFP IN 2 SCP OUT SAND CASTLE S C P OUT DAC 1 2 COLOR SYS IDENT 1H DL CONTROL CW OUT SECAM CONTROL 7 1H DL CONTROL FOR PAL 1 CW OUT COLOR ...

Page 55: ...55 SECTION VIII PIP MODULE ...

Page 56: ...PIN I O NAME 1 0 YS 9 I 5V 2 NC 10 I GND 3 I GND 11 I VD 4 O R OUT 12 I HD 5 O G OUT 13 I O SCL 6 O B OUT 14 I O SCL 7 I GND 15 NC 8 I PIP VIDEO PMUS 02H SN 23148232 4 8V 4 1V 4 8V 4 1V 4 8V 2 8V 350µS 0V 4 2V B Y OFFSET R Y OFFSET TINT RY54 RY55 RY50 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 ...

Page 57: ...IN B Y OUT R Y OUT Y OUT HD VD QY01 m PC 1832GT PIP V C D QY03 TC9083F PIP PROCESSOR SLICE WAVE FORM MODULATION RY55 RY54 PMUS02H BLOCK DIAGRAM OF PIP MODULE BI RI YI HDCN VDCN BO RO YO HDPN VDPN B Y IN R Y IN YIN R OUT G OUT B OUT QY01 m PC1832GT PIP V C D R OUT G OUT B OUT PIP VIDEO VD HD ...

Page 58: ...58 SECTION IX SYNC SEPARATION H AFC H OSCILLATOR CIRCUITS ...

Page 59: ... Theory of Operation 1 1 1 Auto slicer type synchronous separation circuit When a synchronizing signal is separated synchronous separation is made from the beginning with constant voltage in the conventional synchronous separation circuit The auto slider type circuit employed in this time makes synchronous separation at a constant rate against the synchronizing signal amplitude See Fig 9 2 In this...

Page 60: ...se signal for the AFCII loop That is when a phase deference 01 exists in comparison of the phase of fH signal developed by counting down the 32 fH signal and the phase of H sync signal of the broadcasting signal an error signal corresponding to the phase different is detected and a correction voltage 1 corresponding to the error output is generated With this correction voltage the 32 fH oscillator...

Page 61: ...h increasing the sensitivity 3 H OSCILLATOR CIRCUIT 3 1 Outline A 503 kHz 32 x fH voltage controlled type oscillator with a ceramic oscillation element is used to generate a clock pulse and the clock is counted down thereby obviating the need of adjustments for both the H and V deflection process circuit 3 2 Theory of Operation 1 TheHsyncsignalusedasareferencesignalentersfrom the sync separation c...

Page 62: ... x fH pulse with a vertical counter which is reset with a V reset pulse V sync output signal stated under sync separation 5 That is the V output is not created by simply counting down the H by performing V synchronization with a V reset pulse entering within a window provided for V synchronization calleddirecttypesyncsystem thus the circuit can work for non standard signals Fig 9 5 Fig 9 6 Block d...

Page 63: ...63 SECTION X VERTICAL OUTPUT CIRCUIT ...

Page 64: ...ectric charge charged up to a referencevoltageVPdischargesinanconstantcurrentrate and a reference sawtooth voltage generates at point a This voltage is applied to input non inverted input of an differential amplifier A As the amplification factor of A is sufficiently high a deflection current flows so that the voltage V2 at point C becomes equal to the voltage at point a Fig 10 1 Block diagram of ...

Page 65: ...ble to variations of input pulse width The pulse generation circuit also works to fix the V ramp voltage at a reference voltage when the trigger pulse enters so it can prevent the sawtooth wave start voltage from variations by horizontal components thus improving interlacing characteristics Fig 10 4 31 15 14 13 3 6 8 7 6 4 1 5 2 3 C322 R329 Q501 C321 R320 Q302 9V D309 27V R301 R330 C319 C314 Q301 ...

Page 66: ...n in Fig 10 5 Fig 10 6 Output stage operation waveform Fig 10 5 V output circuit 2 In Fig 10 6 a the power Vcc is expressed as a fixed level andthepositiveandnegativecurrentflowinginto the deflection yoke is a current d current b c in Fig 10 6 and the emitter voltage of Q3 and Q4 is expressed as e 3 Q3 collector loss is i1 x Vce1 and the value is equal to multiplication of Fig 10 6 b and slanted s...

Page 67: ...der and a voltage of VP VCC VCE sat VF VCC VF VR VCE sat about 40V is applied to pin 3 9 In this way a power supply voltage of about 27V is applied to the output stage for the scanning period and about 50V for flyback period Fig 10 7 Output stage power supply voltage 5 In this way the circuit which switches power supply circuit during scanning period and flyback period is called a pump up circuit ...

Page 68: ...plied to pin 6 of Q302 to perform S character correction 2 4 2 Up and Down ward Linearity Balance A voltage developed at pin 2 of Q301 is divided with resistors R307 and R303 and the voltage is applied to pin 6 of Q301 to improve the linearity balance characteristic Moreover the S character correction up and down ward balance correction and M character correction are also performed through the bus...

Page 69: ...69 SECTION XI HORIZONTAL DEFLECTION CIRCUIT ...

Page 70: ...tor Q402 at the main power on 2 1 Theory of Operation 1 When the power switch is on the main power supply of 125V starts to rise At the same time AF power supply 25V also rises 2 With25Vlinerisen Q430basevoltagewhichiscreated by dividing the audio power with R433 and D430 also rises Then the transistor Q430 turns on and the HVCC is applied from the audio power line through R432 and D431 to pin 22 ...

Page 71: ...eflown Onthecontrary tocompletely turnoffthetransistor asufficientlyhigh reversevoltage must be applied to the base 3 Whenthetransistorison collectorcurrentismaximum condition with the sufficiently high forward voltage applied to the base the transistor can not be turned off immediately if a reverse base bias is applied to the base because minority carriers storaged in the base can not be reduced ...

Page 72: ...rtransient period of on to off period for the horizontal output transistor 3 2 2 OFF drive system Whenthedrivetransistorison thehorizontaloutputtransistor is off Merit Energy balance between on and off periods of the drive circuit is better and the circuit can be simplified Reverse base current of the horizontal output transistor can be controlled easily Demerit Base emitter forward current flowin...

Page 73: ...ide IC501 is off pin 8 is 0V base emitter bias of Q402 becomes 0V and Q402 turns off and a collector pulse as shown in Fig 11 5 develops at the collector The voltage is stepped down and Q404 is forward biased with this voltage thus turning on Q404 3 In this way by stepping down the voltage developed at primary winding of the drive transformer and by applying it to Q404 a sufficient base current fl...

Page 74: ...t to right in horizontal direction Fig 11 6 IC501 H out Q1 23 33 10 5 2 3 1 HV 8 S charactor capacitor H linearity coil M charactor correction Resonat capacitor Diode modulator circuit To DPC output SIGNAL DEF POWER PCB TP 33 BB31 R411 R410 C413 C416 R416 125V Q402 H drive R415 C417 T401 H drive transformer Q404 H output With damper diode T461 FBT L462 Deflection yoke H coil C463 D461 C444 C440 C4...

Page 75: ...transistor turns off collector current reduces to zero and the deflection current stops to increase 3 t2 t3 The drive voltage turns off at t2 but the deflection current can not reduce to zero immediately because of inherent natureofthecoilandcontinuestoflow graduallydecreasing by charging the resonant capacitor C0 At the same time the capacitor voltage or the collector voltage is gradually increas...

Page 76: ...flection scanning a current flowing through the damper diode scans the left half of the screen the current developed by the horizontal output transistor scans the right half of the screen and for the flybackperiod boththedamperdiodeandtheoutputtransistor are cut off and the oscillation current of the circuit is used Using the oscillation current improves efficiency of the circuit That is about a h...

Page 77: ... circumference area as shown in Fig 11 9 InthehorizontaloutputcircuitshowninFig 11 10 capacitor CS connected in series with the deflection coil LH is to block DC current By properly selecting the value of CS and by generating a parabolic voltage developed by integrating the deflectioncoildcurrentacrosstheScapacitor andbyvarying the deflection yoke voltage with the voltage the scanning speed is dec...

Page 78: ...e on the screen and low at the right side The left right asymmetrical correction is carried out in this way and pictures with good linearity in total are obtained 4 1 3 Horizontal Linearity M character Correction Circuit Since deflection angle increases with size of picture tube increases a M character trend which compresses a picture image at beginning and end of the scanning will occur A M chara...

Page 79: ... on by stepping up the pulse voltage developed for flyback period of the horizontal output circuit with the FBT and supplies the power to various circuit Fig 11 13 10 9 4 7 6 3 2 1 5 Auxiliary winding Primary winding AFC blanking Heater 27V 27 5V 210V 125V C310 C303 D302 C460 D460 R327 R469 D406 C446 C448 D404 C463 T401 CRT anode Focus Screen ABL H deflection coil L462 R441 C442 L441 0 1000VP P 1H...

Page 80: ...upply 5 1 3 27V As a power for the DPC circuit a negative pulse signal is rectified by D460 and filtered with C460 thus developing the 27V 5 1 4 High voltage Singular rectification system which uses a harmonics non resonant type FBT is employed and a better high voltage regulation is obtained so amplitude variation of pictures becomes low Fig 11 14 Fig 11 16 Fig 11 15 115V 0 10 4 7 8 2 1 0 0 0 For...

Page 81: ...ver a capacitance between the internal and external coatings of the picture tube works as a smoothing capacitor Focus voltage is obtained at point EO The FBT is turned to a harmonic of 15 times the fundamental Fig 11 17 Tuned waveforms Flyback pulse 63 5m s AC 0 AC 0 AC 0 Reference wave 45 KHz Harmonics 15 times 675 KHz Tuned waveform 11m s 20m s 1 1 22m s 22x10 45KHz Becomes 45 KHz x 15 675KHz th...

Page 82: ...ion circuit rises When Eb rises emitter voltage of Tr10 divided by R25 and R26 in protectormodulebecomeshigherthan zener voltage 6 2V of ZD6 Tr10 VBE This causes Tr10 turns on to supply base current to Tr9 Then Tr9 turns on By this Tr6 and Tr6 turn on to make ON OFF pulse at pin 7of QA01 in low level QB30andQ843turnsoff thenrelaySR81turnsoff Tr6and Tr7 are in thyristor connection and 5V of power h...

Page 83: ...r module Z801 becomes appprox 0 7V or more Tr 8 turns on and the voltage by divided ratio of R15 and R16 is applied to cathode of ZD4 When this voltage becomes higher than zener voltage of ZD4 ZD4 turns on to supply base current to base of Tr 6 via R14 This causes Tr 5ONandvoltageatpin16ofZ801becomesLow Therefore QB30 and Q843 turns off to set SR81 OFF Tr 6 and Tr 7 in Z801 are in thyristor connec...

Page 84: ...s causing the kink as shown in Fig 11 22 On the contrary when the picture changes from black to white the reverse operation will occur 2 Circuit Description To correct the kink damping circuit is added between the main B power line and the S character capacitor as shown in Fig 11 23 In Fig 11 24 a capacitor C441 is charged with a DC current iB through Q442 connected to MAIN B during the flyback pe...

Page 85: ...85 SECTION XII DEFLECTION DISTORTION CORRECTION CIRCUIT Side DPC Circuit ...

Page 86: ...on neutral voltage setting 5 V M character correction 6 V EHT correction 7 H amplitude 8 L and R pin cushion distortion correction I entire area 9 L and R pin cushion distortion correction II corner portions at top and bottom 10 H trapezoid distortion correction 11 H EHT correction 12 V AGC time constant switching 1 3 Block Diagram Fig 12 1 shows a block diagram of the basic circuit Fig 12 1 V Tri...

Page 87: ...trolling E W output pin 2 of Q302 TA8859P through the bus is shifted in their levels by zener diodes D464 D465 D466 to use them as a negative power source The voltage is added to the amplifier and the output circuit Q462 Q460 and modulates the voltage at CD11 in the diode modulator circuit Thusdevelopedparabolavoltageisanegativevoltage and the sum with the main B voltage VB is applied across the S...

Page 88: ...udepulsesacrossCr asshowninFig 12 5 areappliedtotheprimarywinding the high voltage of FBT also develops a constant voltage WhenthenegativepulsedevelopedatthepointBisintegrated with Lm and Csm its average value appears at Csm as a negative voltage By modulating this voltage to have the parabolic curve with Q460 a waveform of Vm is obtained as shown in Fig 12 6 As a result the voltage Vs which is th...

Page 89: ... the same way the energy stored in the primary winding of the FBT is transferred to the resonant capacitor in the form of Ip In this case the current path is also split into two Ip1 passing through C1 and Ip2 passing through C2 C3 Concequently the current differences between Iy1 and Ip2 Iy1 Ip2 passes through C3 When the high voltage current IH reduces with a dark picture the current Ip in the pri...

Page 90: ...g Period When the base drive current decreases and the H OUT transistor is turned off each energy stored in LDY Lm Lp of FTB is transferred to C1 C2 and C3 respectively and the resonant current becomes zero at a center of the flyback period Then VAandVBpulsesshowamaximumamplitude Fig 12 10 Fig 12 9 Fig 12 11 Fig 12 12 H OUT VA FBT LDY lP Cs VB VB DM IM LM IDC CSM IY Voltage current waveform in H p...

Page 91: ... the maximum 4 1 4 First Half of Scanning Period When the flyback period completes the damper diode DD and the modulation diode DM turn on and the Iy and Im proportionally decrease from the maximum value to zero The H OUT transistor is turned on just preceding at the center of the scanning period and repeats the steps 4 1 1 through 4 1 4 stated above Fig 12 13 Fig 12 15 Fig 12 14 Fig 12 16 IP1 IP2...

Page 92: ...92 SECTION XIII CLOSED CAPTION EDS CIRCUIT ...

Page 93: ...o 15 rows 4 Extended character display of 64 kinds standing for Spanish and the like 5 Representing Background attributes 8 colors transparent 2 DATA TRANSMISSION FORMAT CC EDS data is transmitted being superimposed on line 21 field 1 21H and field 2 284H Waveform of line 21 is shown in fig 13 1 Line 21 signal is composed of data of 7 cycle clock run in start bit and 16 bit 8bits x 2 bytes Fig 13 ...

Page 94: ...de are displayed in black box of 34 characters x 15 rows EDS display format is shown in fig 13 3 The item can be displayed only when data of the item is transmitted Fig 13 3 EDS display format Fig 13 2 Caption Text display area SCREEN LINE 43 LINE 237 ROW1 ROW15 1 CHARACTER BLANK AREA 32 CHARACTERS 1 CHARACTER BLANK AREA Green White Slant Unerline Cyan Network Name Program Name Prog Length Yellow ...

Page 95: ...ta is decoded by command processor and converted to display signal of R G B Ys in Output Logic section The display signal is output at pins 18 2 3 and 17 in the CMOS level of positive polarity The display output and OSD are switched by QR01 in UM01 and the selected signal is sent to V C D IC When the display of CC EDS and OSD are superimposed OSD is the first priority H sync signal with negative C...

Page 96: ... LPF 7 VIDEO QM01 CC EDS DECODER 5 13 17 18 2 3 BOX R G B HIN VIN INVERTER QR01 RGB SWITCH 2 5 3 14 1A 2A 3A 4A 1 3 6 10 13 A B 1B 2B 3B 4B 4 7 0 12 1Y 2Y 3Y 4Y OSD YS OSD R OSD G OSD B 36 37 38 39 OSD YS OSD R OSD G OSD B 30 31 HD OUT VP OUT Q501 V C D UM01 EDS CC RGB SW HD VD Ys OUT R OUT G OUT B OUT 9 13 14 18 19 20 21 2 5 1 6 11 12 SCK SDA Q89 I 2 C BUFFER ...

Page 97: ...K Data CLK Recovery Data MOD XFR BUF SYNC Sllcer COMP SYNC Timing Logic Command Processor and Decoder Control Display RAM CHAR ROM Vertical CTR And Control Horizontal Counter Output Logic R G B Box 18 2 3 17 SMS SEN SCK SDA SDO 6 4 15 14 16 DOT CLK Vss AVSS 1 11 Phase Freq DET PFD Loop FIL Loop Filter VCO HIN 5 9 LPF 13 VIN ...

Page 98: ...98 SECTION XIV POWER CIRCUIT ...

Page 99: ...employs current resonant type which is smaller and more highly effective than conventional type of RCC switching type and employs protector module Z801 whichincludesprotectioncircuitanderroramp forsecondary output detection in one package Fig 14 1 Power block diagram L901 R808 F801 T801 T840 POWER TRANS TPW 1459AZ 12V D840 Q840 5V 1 MICOM PERIPHERALS SR81 F860 D801 R861 Q801 VOLTAGE REGU OVER VOLT...

Page 100: ...icrocomputer 3 MAIN SUPPLY CIRCUIT This circuit is a current resonant switching power circuit using hybrid IC Q801 STR Z3201 The current resonant power supply realizes small highly effective and low noise power Output of main supply are for H deflection circuit 125V for audio output circuit 25V and for signal processing circuit Low B 12V The supply Low B 12V for signal processing circuit is equipp...

Page 101: ... B voltage is detected by error amp to be fed back to the primary OSC circuit via photo coupler then controls frequency Fig 14 4 LC series resonating circuit Fig 14 5 Characteristic 5 FUNDAMENTAL THEORY Voltage generating on L of LC series resonant circuit has characteristicwhichvarieswithfrequencypeakingatresonant point f 1 2p LC Hz as shown in figure 14 4 The circuit utilizes this characteristic...

Page 102: ...nal Pin 5 About lowest oscillation frequency Lowest oscillation frequency is decided by capacitor C862 connected to pin 4 and resistor R867 connected to this terminal 6 CONT terminal Pin 6 About frequency control Current flowing out of this terminal varies charging current of oscillating capacitor C862 Therefore flowing of CONT terminal current corresponding to feedback quantity from photo coupler...

Page 103: ...ion 8 Css Capacitor connecting terminal for soft start 9 CD Capacitor connecting terminal for delay latch ON OFF terminal 10 Vcc Control section power terminal 11 LO Low side gate drive output 12 OC Over current detecting terminal 13 G L Low side MOS FET gate 14 COM Half bridge ground 15 OUT Half bridge output 16 VB High side gate drive power input Fig 14 6 STR Z3201 block diagram 10 16 3 2 1 15 1...

Page 104: ...orm at each pin DATE TIME 4V 2 5V CT PIN VOLTAGE OSC OUT SIGNAL PIN11 LOW SIDE GATE VOLTAGE PIN2 HIGH SIDE GATE VOLTAGE ON OFF OFF ON PIN 15 PUSH PULL OUT VOLTAGE PIN 15 PUSH PULL OUT CURRENT OA OV VIN PIN VOLTAGE PIN 1 ...

Page 105: ...nsformer supplies 200V for video outputfrompin3 27VforV outcircuitfrompin6 and 27V for side DPC circuit from 5 pin respectively Resistors R327 R462 inserted in each line are protecting resistor which fuses in abnormal situation like load short Fig 14 8 Other power circuit 10 9 5 4 7 6 3 2 1 8 27V 27V 200V R642 C461 AFC BLANKING FBT ANODE HEATER FOCUS SCREEN ABL D460 B C448 Q404 Collector D406 C310...

Page 106: ...lifier for B voltage detection This is for the purpose of small size and standardization of protection circuit and what were discrete circuits in conventional chassis are arranged into module Equivalent circuit is shown in figure 14 9 A section is error amplifier for B voltage detection B section is over current protection circuit and C section is X RAY protection circuit D section forces power si...

Page 107: ...D884 R864 Check QA01 pin 7 QB30 Is base voltage of Q843 high level 4 3V Power LED blinks in red Check Repair Q843 SR81 Voltage across C889 Voltage across C897 Check Repair F899 D885 D886 audio power line Check Repair F890 D891 D892 Voltage across C884 jumps instantly to 140V or more Check Repair Q801 D883 D884 Z801 R883 R884 Q862 R864 Is voltage at pin 22 H Vcc of Q501 9V Z801 makes over current p...

Page 108: ... below Check peripherals of V out circuit Q301 and 27V line Open R472 and turn power on again See note below Short R470 and turn power on again See note below Check protector module Z801 and power circuit Check H out circuit C440 C444 and X RAY protection circuit including Z801 Check main B line and H out circuit Q404 4T461 Note Do not take time check within short time NG NG NG OK OK OK Red lights...

Page 109: ...109 SECTION XV DSP CIRCUIT ...

Page 110: ...een center and surround signals requires the amplitude and phase characteristics of the two transmission channels to be as close as possible For instance if the center 1 ORIGINS OF DOLBY SURROUND DolbyStereomoviesandDolbySurroundvideoandtelevision programs include an additional sonic dimension over conventionalstereoproductions TheyaremadeusingaDolby MP Motion Picture Matrix encoder which combines...

Page 111: ...IRCUIT A surround component L R is extracted from L R audio signals coming through the AV SW in the matrix circuit as shown in Fig 15 3 The surround component enters the DSP circuit through the LPF The signal is A D converted delayed by an arbitrary time of 0 100 msec every 3 2 msec by digital process and then D A converted and outputs from the DSP IC The DSP IC develops two outputs LO for FRONT L...

Page 112: ...128 B A D VC TO DIGITAL DELAY 4 CONT BUS CONVERT QD04 From Micro computer VL VR D A D A LO RO Buffer Buffer DQ06 7 QD05 QD05 LO 8 QD06 1 6 12 QD07 DQ02 L R Dolby NR Q640 Rear Amp S L R Speaker QD02 DSP Front Addition Circuit Q670 Front amp L R 5 7 8 10 9 L R L R L S R S L R Speaker Sycrone Super woofer Audio Processor H002 LPF LPF MATRIX L R CIRCUIT 3 1 5 7 3 7 3 9 14 ...

Page 113: ...freverberationsoundinlaterperiod as shown in Fig 15 5 The DSP circuit develops these initial reflection sound and the reverberation sound artificially and add them to the original sounds thereby creating rhe effect that allows the listeners in the home listening room to feel as if they are listening in an original location The DSP IC YM7128B has eight separate output taps and their delay time and ...

Page 114: ...tenuator VL or VR and an analog output is created by D A converter after passing through digital filter comes out from pin 7 or 8 The digital attenuated value delay time and the coefficient of FIR type low pass filter are set by writing the data on the register This process is performed by loading three data from sub microcomputer to microcomputer interface This unit has four modes as surround mod...

Page 115: ...5 1 4 1 3 1 0 9 8 7 2 1 1 1 1 2 1 6 XD01 CD27 RD32 CD29 D01 CD28 RD33 XO XI IC Vss AVDD LD01 LO DC26 DC25 RO VSS AVSS VL VR 2fs 2fs To LPF Output For FRONT ch To LPF Output For REAR ch TIMING GENERATION GL1 GL2 GL3 GL4 GL5 GL6 GL7 GL8 GL1 GL2 GL3 GL4 GL5 GL6 GL7 GL8 B 5V A D CONVERTER D A CONVERTER D A CONVERTER MICROCOMPUTER INTERFACE CD21 CD20 T8 T7 T6 T5 T4T3 T2T1 T0 ...

Page 116: ...uit becomes zero Adjustment by the input balance volume control on the remote hand unit Surround Mode Assumed sound field Front Rear CONCERT HALL Concert hall O O THEATER Movie theater O O NIGHT CLUB Disco Night club O O STADIUM Baseball stadium O O Dolby Surround Dolby surround soft X O OFF Off X X Fig 15 7 Fig 15 8 Table 15 2 dB 0 8 M i n C e n t e r C o n t r o l Lch R c h Response A V SW L OUT...

Page 117: ...requencies higher than 7 kHz in considering processing capacity of the DSP circuit delay connected to next stage and two stages of the filters are employed in this unit Fig 15 9 Fig 15 10 Lch IN REF Rch IN Lch OUT Surround OUT L R Rch OUT CD02 1m50V NP CD03 1m50V NP CD02 39K CD03 39K CD15 39K RD13 39K QD01 Buffer 12 13 14 9 8 10 5 6 7 RD14 39K CD16 33K QD01 Buffer QD01 RD17 10K RD18 10K RD19 10K R...

Page 118: ... signal The DSP circuit is controlled with 3 line bus data from the sub microcomputer The DSP circuit develops two type of outputs one for front addition and the other for rear output Details of the outputs are shown in Table 15 2 Fig 15 11 Bus data Surround IN L R LPF LPF Rear OUT Front OUT DSP QD YM7128B DIN AD SCI XI XO Ycc CH IN CY Lo Ro 16 15 14 13 12 11 10 9 1 2 3 4 5 6 7 8 ...

Page 119: ...and RO outputs must be received at the high impedance input circuits The LPFs which receives the signals consist of OP amplifiers Fig 15 12 QD03 Front Addition circuit Rear Dolby NR circuit DSP LO DSP RO 7 8 CD32 1m 50V CD34 1m50V CD26 33P RD31 1M REF RD34 1M CD25 33P 3 2 3 2 5 6 5 6 1 1 7 7 QD05 QD06 QD05 QD06 RD30 10K RD29 10K RD28 10K CD31 M3300P CD30 820P RD47 10K RD46 10K RD45 10K CD17 M6800P...

Page 120: ...haracteristics are shown in Fig 15 14 Fig 15 14 Fig 15 13 CD35 10m 16V CD38 1m50V CD46 4 7m16V NP Rear OUT Dolby N R Rear IN QD07 TA7629P 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 RD48 5 6K RD49 2 2K RD25 47K RD27 33K REF 12 13 14 RD65 150 CD45 M5600P QD02 RD61 47K CD43 M4700P CD44 M0 027 RD60 47K RD66 18K ENCODE DECODE Dolby NR dB dB Response Response f Hz f Hz ...

Page 121: ...el to provide the surround effect if rear speakers are not used In practice the front addition surround signal output from the DSP circuit is added to Lch with the phase non inverted and to Rch with the phase inverted Fig 15 15 OUT OUT RD01 20K RD05 16K Lch IN Surround L R Rch IN RD09 16K RD10 15K RD07 15K RD04 15K RD06 27K RD08 24K Lch Rch QD02 QD02 Lch OUT REF Rch OUT 5 6 7 9 10 8 ...

Page 122: ... transferred to the data input of the DSP 15 NEUTRAL BIAS To develop a neutral bias voltage for the OP amplifier B 12V is divided with resistors Fig 15 16 Fig 15 17 4 3 2 1 5 6 7 8 To DSP QD03 RD42 1K RD43 1K RD44 1K 5V ICD03 16 pin RD39 100 RD38 100 From main microcomputer QD04 DIN AD SCI GND Vcc RESET SCL SDA RD12 1K RD11 1K B REF CD01 100m 16V ...

Page 123: ...g 15 18 3 1 2 4 7 6 5 Rear INPUT Mute Ripple Filter Vcc Pre GND PW GND Vcc SURROUND SPEAKER TERMINAL Q640 TA8213K C655 0 12m R685 2 2W C652 470m 35V R660 1 5W 5W C650 1000m35V C646 100m 25V R640 6 8K C647 1000P C641 2 2m 50V R641 1 8K R647 22K R644 100K C649 2 2m50V Q641 2SC2878A C645 47m25V ...

Page 124: ...t Buffer QD01 Check DSP front addition circuit QD02 NG NG NG NG OK OK OK OK No rear sound Is rear sound component contained in the input signal Is input applied to pin 4 of QD03 Do pin 7 and 8 of QD03 develop outputs Does Sout 6 develop the output Check Sound volume control circuit H002 and Rear power amplifier circuit Q640 Rear sound is not developed as Adaptive matrix circuit is actuated Use an ...

Page 125: ...125 SECTION XVI FAILURE DIAGNOSIS PROCEDURES ...

Page 126: ...it etc Check X Ray circuit protection circuit To Start circuit diagnosis Check and repair C403 D490 Q501 TA1222N Start circuit diagnosis Start circuit diagnosis Check D431 cathode voltage OK NG NG OK Check voltage at pin 22 of Q501 Check and repair Q501 TA1222N NG OK Check voltage of Audio B line Check and repair power supply circuit Check and repair R432 Q430 D431 and D430 Check and repair C430 C...

Page 127: ... of Q501 with synchronous scope OK NG OK Check pin 15 of Q302 with synchronous scope Check DEF Vcc pin 22 of Q501 is 9 0V V C Vcc pin 40 and 46 of Q501 is 9 0V OK 1 5V Check output circuit Replace Q501 NG OK Check pin 3 of Q302 is 9V Replace Q302 Check and repair 910V D420 Q421 Q420 and R424 Check repair and replace C310 D302 Q301 R327 Check and repair L462 R313 R304 R305 R306 R307 in vertical our...

Page 128: ...rm Parabora waveform Check waveform at Q461 collector Check waveform at Q462 collector Check waveforms at Q462 emitter Q460 collector Check replace or repair C467 C464 D461 L461 Parabola waveform is not observed Parabola waveform is not observed Parabola waveform is not observed Check and repair R469 output circuit Check and repair around Q461 Check and repair D464 D465 D466 R343 R341 R465 Check a...

Page 129: ...T FAILURE DIAGNOSIS PROCEDURES NG OK X ray protection circuit does not work When X R terminals are connected Check voltage at D471 cathode 20 22V Check and repair Z801 Check and repair D471 R472 Check and repair around pin 9 of FBT ...

Page 130: ...with oscilloscope SR81 turns on for a short time but immediately turns off Higher than 130V Higher than 35V Higher than 24 1V Less than 130V Less than 35V Less than 24 1V With SW turned on check 24 5V line voltage with oscilloscope With SW turned on check voltage across C471 with oscilloscope Check C867 D862 D878 Q863 R874 R875 R877 and repair Check over current protection circuit H output and rep...

Page 131: ...SD is OK picture does not appear A V circuit is defective C Picture of only VHF UHF of main screen does not appear D Picture of only VHF UHF of sub screen does not appear E No color After Q501 no color F A V comb etc G Diagnosis of video signal through VIDEO input is done by inner video signal SGV as well In this time do not connect any cable to VIDEO 1 ...

Page 132: ... Check Q501 power Pins 22 40 46 9V Pin 12 5V OK OK OK OK OK OK Check waveform of I2 C bus line Check Q501 and peripherals Check R920 heater resistor and power def circuit Check power def circuit Check CRT and power def circuit Check Q907 Q910 and blanking circuit pow def board Check power line and power def circuit Check I2 C bus line and QA01 MICOM Check QA01 and periheral circuit ...

Page 133: ...prox 0 7VP P Check waveform at pin 15 Y1 output of Q501 Approx 1VP P Check waveform of comb Y output 2VP P Check A V circuit Go to C Check I2 C bus line waveform at pins 27 28 of Q501 Check C203 Check Q501 Check waveform of comb Y input 2VP P Check waveform of comb Y input 0 4 VP P 3 58MHz Check Comb Board Check Q501 Check I2 C bus line and QA01 Check A V circuit Go to C Check Q501 ...

Page 134: ...Check waveform at pin 36 Y AV or QV01 2VP P Check waveform at pin 30 Y Comb or QV01 Check waveform at pin 38 V AV or QV01 Check input waveform 1VP P Video1 Pin 12 of QV01 Video2 Pin 10 of QV01 Video3 Pin 16 of QV01 Go to D E Check QV01 Check QV01 Check Q501 Go to B Check Comb filter Go to B ...

Page 135: ...at pin 7 of H002 Check power voltage at pin 4 of H002 9V Check waveform at pin 2 of H002 Check power voltage of H001 Pin3 9V Pin8 5V Pin9 32V Check waveform at pin 7 of QV01 Replace QV01 Check Replace QV40 QV41 QV42 QV43 Check power circuit Check power circuit Replace H002 OK OK OK NG NG NG NG NG OK OK Replace H001 ...

Page 136: ...TURE DOES NOT APPEAR Picture of only VHF UHF of main screen does not appear Check waveform at pin 15 of HY01 Check power voltage of HY01 Pin9 9V Pin7 5V Pin2 32V Check waveform at pin 28 of QV01 OK OK OK NG NG NG Replace QV01 Check CV09 RV12 Check power circuit Replace HY01 ...

Page 137: ...1 5V Pins 22 40 46 9V Check waveform at pins 5 6 of Q501 Color bar approx 0 6VP P Check waveform at pins 51 52 of Q501 Color bar approx 0 6VP P Check waveform of I2 C bus line Check Q501 Check Q503 and A V circuit Check power def circuit Check Q501 and pins 10 11 peripherals Check C514 C515 Check I2 C bus line and check bus data micom memory etc ...

Page 138: ...itor picture Check waveform at pin 34 of QV01 Check waveform at pin 32 of QV01 Burst 0 3 to 0 6 VP P Check Q501 Check comb filter Check QV01 Check QV01 Check U V tuner IMA module etc Check input waveform as noted below VIDEO 1 pin 14 of QV01 VIDEO 2 pin 10 of QV01 VIDEO 3 pin 18 of QV01 OK ...

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