PT9O A CHASSIS SERVICE MANUAL
Contents
1. PIN CONNECTION Top view 15 PW GND 14 OUTR 13 12 OUTL 11 PW GND 10 MUTE 9 5 9 S GND 7 SVR 6 NC 5 INL 4 VAROUT L 3 VOLUME 2 VAROUT R 1 INR THERMAL DATA O Rth j case Thermal Resistance Junction case 2 8 OW Rth j amb Thermal Resistance Junction ambient ELECTRICAL CHARACTERISTICS Refer to the test circuit Vg 20V Ry 80 Rg 500 29 C Vs Supply Voltage Range rr EN Total Quiescent Current Output DC Offset Referred No Input iua a to SVR Potential ET Quiescent Output Voltage lt Output Power THD 10 eta 80 V 28V p E L DPH THD 1 80 Vs 28V THD 10 R 40 20 7 5 THD 10 80 18V ne Co 1 31 PT 90A Chassis Service Manual ELECTRICAL CHARACTERISTICS continued Symbol Parameter Test Condition Min Typ THD Total Harmonic Distortion Gv 30dB Po 1W f 1KHz in V Ipeak internally limited 24 V G Vol Ctrl gt 4 5V 30 GvLine Vol Ctrl gt 4 5V Zload gt 30 Amin Vol Attenuation at Minimum Volume Vol Ctrl lt 0 5V BW cD Total Output Noise f 20Hz to 22KHz 500 800 V Play max volume f 20Hz to 22KHz 100 250 uV Play max attenuation f 20Hz to 22KHz 150 uV t SR Slew Rate Input Resistance Rvar Out2. 9 A CHASSIS SERVICE MANUAL Modification reserved PI 90A Chassis Service Manual PT 90A Chassis Service Manuai CONTENTS PAGE 1 Technical Data 4 2 Recommendation for service repairs 5 3 Service Menu 6 4 Specification of the connector Euroscart 8 5 Component descriptions 9 6 Introduction 10 7 Block Diagrams 11 8 Fault tracing diagram power supply 14 9 Troubleshooting guide for main PCB 15 10 Descriptions of the integrated circuits ST921x5 MICROCONTROLLEH 17 24C08 NON VOLATILE MEMORY 22 STV224X MULTISTANDARD TV PHOCESSOH 23 MSP34XX D G MULTISTANDARD SOUND PROCESSOR 28 IDA7495 11 11W AMPLIFIER WITH DC VOLUME CONTROL 30 IDA7496 545W AMPLIFIER WITH DC VOLUME CONTROL 33 IDA7494 10W AMPLIFIER WITH DC VOLUME CONTHOL 36 STV5112 RGB HIGH VOLTAGE VIDEO AMP 39 IDA1771 VERTICAL DEFLECTION CIRCUIT 42 STV9306 BUS CONTROLLED VERTICAL DEFLECTION SYSTEM 45 IDA16846 CONTROLLER FOR SWITCH MODE 48 TCDT1100 G OPTOCOUPLER 51 L431 PROGRAMMABLE VOLTAGE REFERENCE o4 SPPO3N60S5 COOL MOS POWER TRANSISTOR 56 SPPO4N60S5 COOL MOS POWER TRANSISTOR 99 7805 POSITIVE VOLTAGE REGULATORS 62 LM317 1 2V TO 37V VOLTAGE REGULATOR 64 BU508DF HORIZONTAL TRANSISTOR 90 66 BU508AF HORIZONTAL TRANSISTOR 110 68 11 Chassis replacement part list 71 PI 90A Chassis Service Manual TECHNICAL DATA CRT PANEL EN Visible Picture 20 21 28 Deflection Angle 90 110 Vertical Frequency 50H
3. B 6 Tuner Type 00 Alps 01 Temic 10 Philips UV1316 11 Thomson Orega Option Byte 2 76543210 BO AV 2 1 AV 2 available 0 AV 2 Not Available B1 VHS 1 SVHS available 0 SVHS Not Available B2 TR1 Turkish language available 0 Turkish Language not available B3 ES1 Ecoswitch available 0 Ecoswitch not available B4 CL1 Child Lock available 0 Child Lock not available B5 HP1 Headphone available 0 Headphone not available B6 S WO Subwoofer available 1 Subwoofer not available B7 4 8 Picture tube 0 16 9 Picture tube Options B4 7 are only relevant if the corresponding modules are present in the software Option Byte 3 76543210 BO 1 Crystal application SS 1 Intercarrier application B2 APR1 APR ON B3 OSD 1 OSD contrast control ON B4 5 1 Blue screen disabled B5 AVL1 AVL ON CLP 1 Clipping Mode compromise B7 STB1 Stanby after power on Two Crystal application for NTSC playback QSS application APR OFF OSD contrast control OFF Blue screen enabled AVL OFF reduce tone MSP No standby after power on GEOMETRY 90 deg Chasis V SIZE 4 3 50Hz V SIZE 16 9 50Hz V SIZE 4 3 60 Hz V SIZE 16 9 60 Hz V POS H POS GEOMETRY 110 deg Chasis with STV9306 IC VIDEO TUNERIIF V SIZE V POS V C CORR V S CORR H SIZE H PINC CORR H KEYS CORR H COR CORR H POS R GAIN G GAIN B GAIN R CUTOFF G
4. Although the ST9 has an 8 bit ALU the chip handles 16 bit operations including arithmetic loads stores and memory register and memory memory exchanges Two basic addressable spaces are available the Memory space and the Register File which includes the control and status registers of the on chip peripherals Power consumption of the device can be reduced by more than 95 Low power WFI Up to 28 I O lines are dedicated to digital Input Output These lines are grouped into up to five I O Ports and can be configured on a bit basis under software control to provide timing status signals timer and output analogue inputs external interrupts and serial or parallel A set of on chip peripherals form a complete system for TV set and VCR applications Voltage Synthesis VPS WSS Slicer Teletext Slicer Teletext Display RAM OSD Pig ST921x5 Microcontroller Block diagram PT 90A Chassis Service Manuai GENERAL FEATURES Register File based 8 16 bit Core Architedure with RUN WFI SLOW and HALT modes e 0 C to 700C Operating Temperature Range available e Up to 24 MHz Operation 5V 10 Minimum instruction cycle time 375nS at 16MHz internal clock 64K Bytes ROM e 256 Bytes RAM of Register file accumulators index registers e 256 Bytes of on chip static RAM 8K Bytes of TDSRAM Teletext and Display RAM e 56 lead Shrink DIP package e 28 fully programmable I O pins e Serial Peripheral
5. normal and wide ACC overload circuit Chroma subcarrier output which could be used to drive comb filter circuit Automatic RGB peak regulation Automatic digital cut off current loop with warm up detection circuit White point and cut off point adjustments Beam current limiter control stage High performance synchronization pulses separator Horizontal synchronization with two phase locked loops 26 Integrated VCO auto calibration using the chroma crystal reference frequency Automatic time constant selection for the first PLL 3 selectable time contants Video identification circuit independant from PLL1 Noise detector circuity Vertical countdown circuit Automatic 50 60Hz selection circuit Blanking and inserted cut off pulses position adapted to standard 50 or 60Hz Long blanking mode capability in 6 2 same blanking as 50Hz standard Possibility to insert cut off pulses after a vertical oversize blanking signal De interlace capability Horizontal starting circuit with soft start capability Horizontal and vertical position adjustments vertical amplitude control voltage combined with chroma subcarrier output 4 3 16 9 selection voltage PT 90A Chassis Service Manuai ABSOLUTE MAXIMUM RATINGS T 8V supply voltage o DL O 5V supply voltage V V Operating Temperature storage Temperature 55 4150 C THERMAL DATA Rth j a Junction
6. 90A Chassis Service Manual TROUBLESHOOTING GUIDE FOR MAIN PCB TROUBLE CHECK POINTS Horizontal size CD03 CD04 CD05 1001 CD06 1021 DD22 115V adj Verticable size 1021 ID41 CD26 CD44 RD10 RD17 0007 0008 RD29 RD50 Horizontal Linearity 003 RD14 Verticable linearity RD49 CD43 Noise picture TUO1 IF adj AGC adj White screen RDO8 ICV2 91921x5 Microcontroller Microcontroller OSD Teletext decoder VPS PDC WSS decoder are embeded in one chip where there are two types with the major difference ST92185 No teletext ST92195 With teletext The ST92195 microcontroller is developed and manufactured by STMicroelectronics using a pro prietary n well HCMOS process Its performance derives from the use of a flexible 256 register pro gramming model for ultra fast context switching and real time event response The intelligent on chip peripherals offload the ST9 core from I O and data management processing tasks allowing critical application tasks to get the maximum use of core resources The ST92195 MCU supports low power consumption and low voltage operation for power efficient and low cost embedded systems The advanced ST9 Core consists of the Central Processing Unit CPU the Register File and the Interrupt controller The general purpose registers can be used as accumulators index registers or address pointers Adjacent register pairs make up 16 bit registers for addressing or 16 bit processing
7. CUTOFF AGC PIF COARSE PIF FINE PIF C OARSE L PIF FINE L PT 90A Chassis Service Manuai gt lt Is the VCO status indicator for adjusing the PIF to 38 9Mhz for BGDKIL and 33 9 for L standards thru bus controlled VCO The VCO status is read from the read register of STV224X and guides whether to Increase Decrease the VCO registers to attain VCO OK Status For doing VCO adjustment Feed a 38 9MHz Carrier as IF input and adjust PIF Coarse and fine parameters to get VCO OK Status For doing VCO L1 adjustment Feed a 33 9 MHz carrier as IF input and adjust PIF Coarse L and PIF Fine L to get VCO OK Status PT 90A Chassis Service Manual SPECIFICATIONS OF THE CONNECTOR EURO SCART l Audio output 1 right channel 0 5 5 lt 0 2 Audio input 1 right channel 0 5 VRMS connected to No 6 3 Audio output 2 left channel 0 5 VRMS connected to No 1 4 GND audio 5 GND 6 Audio input 2 left channel 0 5 VRMS gt 10k 0 7 RGB input blue B 8 Switch signal video status 9 GND 10 Reserved for clock signals not connected 11 RGB input green G 12 Reserved for remote control not connected 13 GND 14 GND switch signal RGB 15 RGB input red R 16 Switch signal RGB 17 GND video 18 GND19 Video output 1 Vpp 75 ohm 20 Video input 1 Vpp 75 ohm 21 Shield 1 3 5 9 1113 15 1 19 21 2 4 6 8 10 12 14 16 18 20 COMPONENT DESCRIPTIONS PT 90A Chassis Service Manuai POWER CO
8. CVBSIN3 Y SVHS or CVBS3 External Input 23 Chroma SVHS input 29 25 BEXT 26 GEXT 27 FBEXT 29 30 BOUT 31 GOUT 32 ROUT 33 cam 34 BOSD 35 GOSD 36 ROSD 37 FBOSD 38 XTAL3 BTUN 39 XTAL2 40 XTAL 1 41 CLPF 42 X1 VAM CHROUT 43 44 CVBSOUT 1 5 Voc 46 BCL SAF 47 VERT 48 HOUT 49 LFB SSC 50 SLPF 51 52 5 Veco 94 GND D MainAudio Output 24 PT 90 Chassis Service Manual L 9 2 T E S dkk 88 5 s T n Hia JOH1NOO E 61 H30023g 1 WYA 2222222 9s1Nmvo3asrivd sna LH A r H3TIM Y r LOND H dOO pug LNAI OLN avi NOZIEOH V LNOZIHOH ET 5 01 4I QNO SNINNY2S 1H3A 27 Hala 25 5 5 106 ino 1 A inoa n ONDINW TH 29 avoutsoov 5 330 1112 305 108 z ZNIJIS lt q saweg H3Nn1 H8 10099 VH3Nh1 Tid A KR H31 1s VINOHHO F SNIMY 3d 10 YAN LNIIS dv2JIdo9v ZNidld 9 99v oo ORAS RA uS um oou ec a i i 8 15 amp S CVBSIN1 FMCAP E
9. Interface Flexible Clock controller for OSD Data Slicer and Core clocks running from one single low frequency external crystal Enhanced Display Controller with 26 rows of 40 80 characters Serial and Parallel attributes 10x10 dot Matrix 512 ROM characters definable by user 4 3 and 16 9 supported Rounding fringe double width double height scrolling cursor full background colour semi transparent mode and reduced intensity colour supported Teletext unit including Data slicer Acquisition Unit and up to 8K Bytes for Data Storage e VPS and Wide Screen Signalling slicer e Integrated Sync Extractor and Sync Controller 14 bit Voltage Synthesis for tuning reference voltage Up to 6 External Interrupts plus 1 non maskable interrupt e 8 x 8 bit programmable PWM outputs with 5V open drain or push pull Capability e 16 bit Watchdog timer with 8 bit prescaler 16 bit standard timer with 8 bit prescaler usable as a Watchdog timer e 3 channel Analog to Digital converter 6 bit guaranteed e Rich instruction set and 14 Addressing modes PI 90A Chassis Service Manual Block Diagram Up to 96 Kbytes ROM 7 256 or 512 bytes RAM 2 Up to 8 Kbytes TDSRAM 256 bytes Register File 8 16 bit CPU 1 0 lt Porto KL 2 0 7 0 PORT 2 5D 2 5 0 K 2 Pair CJ una KEO aro lt N MMU jn SATA on Management _ INTO CVBS1 STO COR
10. Sub mode Volume DownOVolume Volume e Volume Up1 Volume Volume Programme Down2Programme Page e Programme Down3Programme Page Power Mode Control The STDBY pin 14 output specifies the mode which the set is in Stand by mode or Operating mode Table Power Modes ST BYMode e 1 Stand by e 0 Operating Lines Pin 20 SCL and Pin 19 SDA accept inputs from the bus is a 2 wire bi directional bus PT90A has an on chip bit level interface This means the bus arbitration the reception and transmission of data bits and the generation of START and STOP are manipulated by the hardware The software must be able to handle these bits i e save a received bit and prepare the bits to be transmitted If a transmission does not succeed the software will retry for 5 times If the bus is occupied for more than 1 18 ms the microcontroller will attempt to free the bus PT90A supports a 1K EEPROM M24C08 BN6 used for storage of analogue controls tuning data for 100 pre selected programmes and options The FC addresses of the EEPROM is described in the following chapters Furthermore the video processor STV224x is controlled bus on address 21 PI 90A Chassis Service Manual 24C08 Non Volatile Memory These l C compatible electrically erasable programmable memory EEPROM is organized as 1024 x 8 bit and with a power supply of 5 V The memory behaves as a slave device in the proto
11. ambient Thermal Resistance Measured at 1W SDIP56 C W ELECTRICAL CHARACTERISTICS Supplies at Typical Values 25 C bus register at power on reset value unless otherwise specified SUPPLY IF Circuit Supply Voltage Vecp Bus amp Digital Supply Voltage Chroma Scanning Supply Voltage Voce ICCF ICC1 leco Current Consumtion V Total Power Dissipation Vcco 78V Vecir 5 5v 27 PI 90A Chassis Service Manual MSP34XX D G Multistandard Sound Processor The MSP34xx D G family of single chip Multistandard Sound Processors covers the sound processing of all analog TV Standards worldwide as well as the NICAM digital sound standards The full TV sound processing starting with analog sound IF signal in down to processed analog AF out is performed on a single chip It covers all European TV Standards The MSP 3400 1 0 m CMOS version is fully pin and soft ware compatible to the MSP 3410 but is not able to de code NICAM It is also compatible to the MSP 3400C 0 8 m CMOS version The IC is produced in submicron CMOS technology combined with high performance digital signal processing The MSP 34100 is available in a PLCC68 PSDIP64 PSDIP52 in a PQFP80 package Note The MSP3410D version is fully downward compatible to the MSP 3410B the MSP 3400B and the MSP3400C To achieve full software compatibility with MSP3400C MSP 3400B an
12. E SITION OSCIN OSCOUT RESET RESETO e VPS WSS MR K gt DATA WSCR WATCHDOG 1 e SDO SDI CVBS2 CA 5 EK eon f PEE TIMING AND CLOCKCTRL 59 VOLTAGE CONTROL HSLNCICSYNC VS0 2 1 t 7 c m TT CP ON SCREEN MULTIP PXFM DISPLAY R G B FB STOUTO STANDARD A 5 rer M PWM HT SDAQISCLE ee ra wH 120 CONVERTER 18 4 Pin description IR IN RESET NC NC NC NC 76 NC CL1 8 NC 9 NC NC SW LL AV STDBY B R FB SDA SCL VDD JTDO WSCF WSCR AVDD3 TESTO MCFM JTCK KB Input NC NC NC CL2 XTAL XTAL NC NC STDBY1 NC NC MUTE VOL NC VSYNC 40 HSYNC AVDD1 PXFM JTRSTO GND AGND TELETEXT WSS JTMS AVDD2 CVBSO TXCF 19 PT 90A Chassis Service Manuai PT 90A Chassis Service Manual PINNING Pin Symbol Function ne Symbols UEUDCHOD 2 3 4 5 6 7 8 9 0 1 12 13 P3 5AVO Sound switch for two AV 14 15 17 18 19 5 1 0 02 Data Line 20 21 22 4 slicer line PLL i Slicer line PLL 25 AVDD3AVDD3 35V Analog VDD For PLL 26 TESTOTESTO 27 MCFBMCFB Analog Pin for VPS WSS line PLL 8 JTCKJTCK i WSS line PLL 0 2 4 36 Analog pin for display pixel freq multiplier AVDD1AVDD1 Analog Power Supply 0 HSYNCHSYNCI Horizontal Sync Input NO Go Go Co CO CO C2 N amp
13. RD Rer SAW FILTER IR SENSOR S VOLTAGE REGULATOR dle ON OFF SWITCH LINE FILTER PTC NPN TRANSISTOR PNP TRANSISTOR CERAMIC FILTER COIL TT LINEARITY COIL o m IW METAL OXIDE RESISTOR 1 2W METAL OXIDE RESISTOR 1 4 OR 1 6W CARBON FILM RESISTOR c wander TACT SWITCH PI 90A Chassis Service Manual INTRODUCTION is a low cost multi standard television receiver control system based on ST921x5 microcontroller family It is a frequency synthesis tuning FST system with on screen display OSD for all necessary control functions The system is based on the controlled one chip video processor IC STV224x which can support a Nicam and a German stereo sound system based on MSP as well as mono sound PT90A has the ability to control two scart connections and headphone inputs Teletext is handled by the microcontroller on chip teletext interface The user interface is menu controlled for easy access with remote control or local keyboard keys 1 1 Definitions acronyms and abbreviations ADC Analogue to Digital Converter AFC Automatic Frequency Control AV Audio Video peripheral TV signal source DAC Digital to Analogue Converter FE Front End 2normai TV mode FST PLL Frequency synthesis Tuning Phase Locked Loop e PC Inter bus 2 wire bidirectional multimaster bus e IDENT Horizontal coincidence signal transmitter IDENTificat
14. RGB Externals TDA1771 90 V Amplifier SCART 2 BU2508DF H Deflection amp EHT CVBS INT1 ol Flyback CVBS ST92195 u Controller Teletext Decoder EPG RGB Processing Supply Degaussing TDA16846 SMPS PCA8521 RC 5 Transmitter 90 MONO CHASSIS 20 PLL Tuner 1 AGC SAW _ K2966 VIF TV2246 47 48 PAL SECAM NTSC TV Signal Proc Externals CVBSSC1 CVBSSC2 CVBS INT1 SCART 1 SCART 2 192185 T92195 NO TXT u Controller CVBS Teletext Decoder EPG RGB Processing 8521 RC 5 Transmitter FM Mono AM Mono Iblack PT 90A Chassis Service Manuai TDA7494 Amplifier STV5112 RGB Output Amplifier RGB TDA1771 ed V Amplifier BU2508DF H Deflection amp EHT EHT Flyback Supply Degaussing TDA16846 SMPS PT 90A Chassis Service Manual Basic Hardware Specification The following are the components that a PT90A controlled system consists of e 51921 5 TV OSD TXT controller with PT90A software inside 24C08 102478 bit NV Memory EEPROM for storage of favourite programmes preffered sound and picture controls service menu settings SIV224x bus controlled multi standard one chip TV processor Pre programmed RC 5 remote control transmitter e Temic Alps Philips Thomson Oreg
15. Variable Output Resistance V us 22 5 30 S CHEM Rload Var Out SVR Supply Voltage Rejection f 1kHz max volume 3 CsvR 470uF VRIP 1Vrms f 1kHz max attenuation 5 CsvR 470uF VRIP 1Vrms SSS 10 Ts Thermal Shut down MUTE STAND BY amp INPUT SELECTION FUNCTIONS VST BY Stand by threshold 2 3 2 9 2 2 VuurE Mute threshold IqST BY Quiescent Curren amp Stand by AMUTE Mute Attenuation SSH 20 IstbyBIAS Stand by bias current stand by on VsT BY 5V VMUTE 5V Play oF Mute mutsias Mute bias current NENNEN 2 5 gt gt gt NO UA
16. a PLL Tuners 90 Chasis DA 1771 Vertical Deflection IC 110 Chasis e SI V9306 bus controlled vertical deflection and E W correction circuit For stereo systems the following optional device is supported MSPXX D G German and NICAM stereo sound decoder Communication between the microcontroller master and all related devices slaves is carried out by means of the two wire bidirectional lC bus This chapter describes all of the functions and hardware equirements of PT90A The overall control of the system is handled by the microcontroller which performs the following Decodes the serial data from the remote controller Scans the local keyboard Controls the OSD Exchanges information via the serial bus Selects the proper tuner tuner band e Selects the proper IF and the sound demodulator Analogue picture controls Switches between internal and external audio and video signals 5 1 Interface Description 5 1 1 Remote Control Handset The remote control handset which is compatible with RC 5 standard 5 1 2 Remote Control Decoding The infrared remote control pulses are modulated at the standard RC 5 frequency of 36 KHz The remote control signal active HIGH from the IR receiver TFMK1380T is fed to the external interrupt input IR INPUT of the microcontroller Finally the video identification in STV224x is checked to make sure that the search terminated on a video carrier For SECAM L France VHF cha
17. co 20 PT 90A Chassis Service Manuai RESET Reset input is an active low one ST921x5 is initialized by the RESET signal When the RESET deactivated programme execution starts from the 00H and 01H addressed programme memory locations H G B BLANK The video colour analogue DAC outputs are Red Green Blue Fast Blanking XTAL These pins are used to connect parallel resonant crystals of 4 MHz Status Logic Level Control High or Low Pin 8 and Pin 52 monitor the status of the AV SCART connectors The controller detects the transitions at these pins When the signal goes from high to low the TV set will automatically switch to AV mode The signal going from low to high will lead the TV set to go back to the previous source Voltage Level Control O 12V Voltage measurement values are taken from these pins 4 3 or 16 9 picture ratio from SCART or TV mode selection is dependent on the voltage values at these pins User control always has a priority in both TV and mode Following the change of source or the channel 4 3 format is assumed by default The voltage values stated below are divided by 3 at the microcontroller pins Status Pin 8 Picture Ratio 0 2 0 VIV Mode 2 0 4 5V No change 4 5 7 0V 16 9 Scart 7 0 9 0V No change 9 0 12 0V 4 3 Scart Keyboard Scan Lines The 4 keys of the local keyboard are scanned by an ADC used by the microcontroller Table Local Keyboard Name CodeTV ModeTXT
18. col with all memory yperations synchronized by the serial clock Read and Write operations are initiated by a START condition yenerated by the bus master The START condition is followed by a Device Select Code and RW bit terminated by an acknowledg bit Table 6 DC Characteristics T a 0 to 70 C 20 to 85 C or 40 to 85 C Vcc 3V to 5 5V 2 5V to 5 5V or 1 8V to 5 5V lLO Output Leakage Current OV xVgyr lt Er 5 jme Rise Fall time lt 10ns supply Current 5725 series Vec 2 5 fc 100kHz Vin Vss Or Voc Icc Supply Current Standby VCC 5V ST24 series Vin Vss Vec Vcc 100kHz VIN Vss Voc Icc2 Supply Current Standby VCC 2 5V ST25 series Vin Vss or Vec Veg 2 5V fc 100kHz Vin Vss or Icc3 Supply Current Standby VCC 3 6V ST24C08R Vin Vss or Vec Vcc 3 6V fc 100kHz Vin Vss or 4 Supply Current Standby VCC 1 8V ST24C08R Vin Vss Vec Vec 1 8V fc 100kHz Vib Input Low Woltage SCL SDA 53 O3Vgc Vir Input High Woltage SCL SDA pua vaa s Vi Input Low Woltage E PRE MODE WC VIH Input High Woltage E PRE MODE WC vcc to RN Re Output Low Voltage S124 series Vec 9V ULM VOL Output Low Voltage ST25 series 2 1 Vec 2 5V Output Low Voltage ST24C08 series ICL IMA Vec 1 8V 0 3 V 22 PI 90A Chassis Service Manuai SIV224X Mul
19. cvasouri CVBSIN2 YICVBSINS S 35 PT 90A Chassis Service Manual MAIN FEATURES bus control readl and write modes PIF PLL demodulator Bus controlled VCO alignment IF positive and negative modulation Digital AFC Tuner delayed AGC output White and Black spot cancellation SIF with QSS or intercarrier structure Built in sound bandpass Multistandard PLL FM demodulator 4 5 5 5 6 0 6 5 AM demodulator for France FM sound carriers output for Stereo chassis Audio switch for external audio input Mono chassis Digital volume control Audio Mute Video switch 3 CVBS inputs 1 CVBS output which can be used to drive teletext decoder SVHS switch Y input is combined with CVBS3 input OSD RGB analog inputs fast blanking detection on OSD fast blanking pin contrast control capability oversize blanking capability on OSD fast blanking input External analog RGB inputs with contrast and saturation control external RGB matrixed in YUV Integrated chroma filters trap bandpass cloche with automatic alignment Integrated luminance delay line Adjustable peaking on the luminance signal with coring function Black strech circuit PAL SECAM NTSC color decoder with automatic identification of standards Integrated chroma delay line Full integrated SECAM decoder Hue control two selectable matrixes in NTSC mode Automatic flesh control circuit with two selectable characteristics
20. d MSP 3410B the demodulator part must be programmed as described in the data sheet of MSP 3410B MSP 3410D Additional Features AVC Automatic Volume Correction Subwoofer Output 5 band graphic equalizer as in MSP 3400C Enhanced spatial effect pseudostereo basewidth en largement as in MSP 3400C Headphone channel with balance bass treble loud ness Balance for loudspeaker and headphone channels in dB units optional Additional parr of D A converters for SCART2 out Improved oversampling filters as In MSP 3400C Additional SCART input Full SCART In out matrix without restrictions scart volume in dB units optional Additional 125 input as in MSP 3400 New FM identification as in MSP 3400C Demodulator short programming Autodetection for terrestrial TV sound standards Precise bit error rate indication Automatic switching from NICAM to FM AM or vice versa Improved NICAM synchronization algorithm Tmproved carrier mute algorithm Improved AM demodulation ADR together with DRP 3510A Dolby Pro Logic together with DPL 35xx A Reduction of necessary controlling Less external components Significant reduction of radiation 28 Pin description NC AUD CL OUT D CTR OUT1 D CTR OUTO ADR SEL STANDBYQ 6 PC CL 78 l S CL 9 l S WS S DA OUT S DA IN1 ADR DA ADR WS ADR CL DVSUP DVSS l S DA IN2 NC RESETQ DACA R DACA L VREF2 DACM R DACM L DACM SUB MSP3410D PT 90A Chassis Service Ma
21. ersons have to rid themselves of electrostatic char ges by touching MOS components Hold the component by the body touching the termi nals Use only grounded instruments for testing and pro cessing purposes Remove or connect MOS ICs when operating volta ge is disconnected tage be recorded as a part of the service record It 1 lt important to use an accurate and reliable high volta ge meter The primary source of X RAY radiation in this TV re ceiver is the picture tube For continued X RAY radi ation protection the replacement tube must be exactly the same type tube as specified in the par list PT 90A Chassis Service Manual SERVICE MENU The service menu is entered by pressing a special 4 digit code if the feature menu is displayed and TV is in FE mode While TV isn t in AV Mode and fetura menu is displayed pressing sequence of digits 1923 will enter the TV to service mode and service menu will be displayed OPTIONS Option Byte 1 76543210 BO 1 B G Standard available 0 Not available B1 1 DK Standard available 0 Not available B2 1 Standard available 0 Not available B3 1 L Standard available 0 Not availabie B5 4 TTX National Character Set Group 00 Seti ENGLISH GERMAN SWEDISH ITALIAN FRENCH SPANISH CZEKOSLOVAKIAN RUMANIAN 01 Set2 POLISH GERMAN SWEDISH ITALIAN FRENCH SERBO CROATIAN CZEKOSLOVAKIAN RUMANIAN 1X Set 3 ENGLISH GERMAN SWEDISH ITALIAN FRENCH SPANISH TURKISH RUMANIAN
22. ion LS Loud Speaker HP Headphone MS Multi Standard NV Memory Non Volatile Memory OSD On Screen Display PP Personal Preference e RC 5 Remote Control System complying with RC 5 world standard Video Proc STV223x integrated bus controlled multisystem one chip TV processor PIF Picture Intermediate Frequency SIF Sound Intermediate Frequency NICAM Near Instantaneous Companded Audio Multiplex 2 Block diagram Figure 1 2 and 3 shows the basic block diagram of PT90A PT 90A Chassis Service Manuai PI90A 110 STEREO CHASSIS m TDA7495 MSP34XX PLL Tuner 1 dm Sound Processor Amplifiers scarts L R AGC FMcar AM Mono SAW K9453 RGB STV5112 RGB Output Amplifier TV2247 48 PAL SECAM NTSC Audio TV Signal Proc Externals CVBSSC1 STV9306 V Amplifier amp E W SCART 1 CVBSSC2 SCART2 598 CVBS INT1 BU2508AF gt H Deflection Flyback amp EHT CVBS 51792195 u Controller Teletext Decoder EPG RGB Processing Degaussing TDA16846 SMPS poagsz1 RC 5 Transmitter 90 Chassis Service Manual 90 STEREO CHASSIS lC 20 TDA7496 MSP34XX PLL Tuner 1 mn SH Sd Sound Processor Amplifiers Scarts L R Eg AGC STV5112 RGB Output Amplifier TV2247 48 PAL SECAM NTSC TV Signal Proc Audio CVBSSC1 SCART 1 CVBSSC2
23. nnel search starts with the highest channel frquency and all steps atre carried out in the reverse order When micro search fails to find a signal in a channel it will tune the standardised channel frequency Sound Systems PT90A supports stereo sound system as well as mono both controlled via FC bus from the video processor Sn 224x Mono Sound Sysfem The only available sound control is volume In FE mode after tuning a programme the system always selects the sound witta the following priority AMSound If a transmitter is tuned with colour standard SECAM L L the sound will be forced to AM The AM sound system is automatically forced via the STV224x when positive modulation SECAM L or SECAM L is selected Sfereo Sound Sysfem Direct control of the audio functions on the remote transmitter as individual buttons are personal preference function volume mute mono stereo language Automatic identification and decoding of German Stereo and NICAM sound systems A German Stereo A2 Mono Stereo Dual II B NICAM Stereo Mono Stereo Dual I Il C Mono Only mono PT 90A Chassis Service Manuai TROUBLESHOOTING GUIDE FOR SMPS SMPS DEFECTIVE FUSE FP01 Yes DEFECTIVE VOLTAGE DRAIN DP01 04 CP01 04 IP01 VOLTAGE AT PIN 1 lt 1V MEASURE 115 145V 115 145V ADJUSTABLE WITH VAPI 2 VAP1 2 05 DP61 CONTROL RANGE OF SMPS PT
24. nuai XTAL OUT XTAL IN TESTEN ANA IN2 ANA IN ANA IN1 AVSUP AVSS MONO IN VREFTOP SC1 IN R SC1 IN L SC2 IN R SC2 IN L SC3 IN R SC3 IN L AGNDC AHVSS CAPL M AHVSUP CAPL A SC1 OUT L SC1 OUT R VREF1 SC2 OUT L SC2 OUT R PT 90A Chassis Service Manual TDA7495 11 11W Amplifier With DC Volume Control 11 11W Output Power RL 80 10 VCC 28V ST BY and mute functions Low turn on turn off pop noise Linear volume control DC coupled With Power Op Amp No Boucherot Cell No ST BY RC input network Single supply ranging up to 35V Multiwatt 15 Short circuit protection ORDERING NUMBER TDA7495 Thermal Overload protection Internally fixed gain Soft Clipping Variable output after volume control Circuit multiwatt 15 package Block and Application Diagram VAROUT R Vs 470nF 30K 1 ST BY 45M S GND Y S GND Q O 45M VOLUME S2 MUTE 5 MT 1n gt i J 22 dil SVR 470uF Q T VOLUME VAROUT_L Er i 400nF 300K D96AU440B L PI 90A Chassis Service Manuai ABSOLUTE MAXIMUM RATINGS 1 Vg DC Supply Voltage Vin Maximum Input Voltage Ptot Total Power Dissipation Tamb 70 Ambient Operating Temperature 1 20 to 85 Tj storage and Junction Temperature 40 to 150 1 Operation between 20 to 85 guaranteed by correlation with O to 70
25. tistandard TV Processor SI V224X is a fully bus controlled IC for n including PIF SIF Luminance Chrominance and deflection processing It is a bus controlled PAL SECAM NTSC single chip TV Processor For details of STV224X features please refer to the STV224X datasheet 110 4 3 or 16 9 CRT application It integrates both vertical deflection and E W correction circuit necessary for design of 110 chassis it allows designing a PAL NTSC BGDKIMN set with very few external componentsand no manual adjustment Pin connections SIFIN1 FMCAP SIFIN2 AUDIOOUT AGCSIFCAP GND D VCCD AGCPIFCAP SDA PIFIN1 SCL PIFIN2 SLPF TUNERAGCOUT LBF SSC IFPLL 9 HOUT GND IF VERT AM FMOUT BCL SAF IF CCI INTCVBSOUT CVBSOUT1 EXTAUDIOIN GND PIFLC1 X1 VAMP CHROUT PIFLC2 CLPF VCC2 40 XTAL1 CVBSIN1 XTAL2 GND2 XTAL3 BTUN CVBSIN2 FBOSD BS ROSD Y CVBSIN3 GOSD CHR BOSD APR ICATH BEXT ROUT GEXT GOUT REXT BOUT FBEXT NC 23 PI 90A Chassis Service Manual Pin Symbol SIFIN1 2 SIFIN2 3 AGCSIFCAP 4 VREF IF 5 AGCPIFCAP 6 PIFIN1 7 2 8 TUNERAGCOUT 9 IFPLL 10 GND IF 11 AM FMOUT 2 Voc IF 13 INTCVBSOUT 14 EXTAUDIOIN 15 PIFLC1 16 PIFLC2 17 Vec2 Video Luma Supply Voltage 8V 18 CVBSINT 19 GND2 20 CVBSIN2 Black Stretch Capacitor o O 55 AUDIOOUT 96 FMCAP Main Audio Output FM Demodulation Capacitor NO Coco gt Eol Cc 21 Black Stretch Capacitor 22 Y
26. y evacuated and if broken Glass fragments will be violently expelled Always discharge the picture tube anode to the rece iver chassis to keep of the shock hazard before re moving the anode cap Keep wire away from the high voltage or high tempe rature components When replacing a wattage resistor in circuit board keep the resistor 10 mm away from circuit board HANDLING OF MOS CHIP COMPONENTS MOS circuit requires special attention with regard to static charges Static charges may occur with any highly insulating plastics and can be transferred to per sons wearing clothes and shoes made of synthetic ma terials Protective circuits on the inputs and outputs of mos circuits give protection to a limited extend only due to time of reaction Please observe the following instructions to protect the components against damage from static charges 15 Keep mos components in conductive package until they are used Most components must never be sto 2 X RAY RADIATION PRECAUTION 1 Excessive high voltage can be produce potentially hazardous X RAY radiation To avoid such hazard the high voltage must not be above the specified li mit The nominal value of the high voltage of this re ceiver is 25KV at zero beam current minimum brightness under 220V AC power source The high voltage must not under any circumstance exceed 30KV It is recommended the reading of the high vol red in styropor materials or plastic magazines P
27. z Horizontal Frequency 15 625Hz ELECTRONIC Program Number 100 AV Teletext Flof text Cable tuner 8 MHz spacing for Hyper Band TV System European CCIR system 90 2x4 Watt 110 2x8 Watt Rms 10 distortion CONNECTIONS Euro AV Socket Include MAIN STAGE Mains Voltage 165 260VAC Mains Frequency 50Hz Power Consumption 20 21 75 Watt 28 126 Watt In Stby Mode 20 21 7 Watt 28 8 Watt PT 90A Chassis Service Manuai RECOMMENDATION FOR SERVICE REPAIRS Use only original spare parts Only use components with the same specifications for replacement Original fuse value only should be used Main leads and connecting leads should be checked for external damage before connection Check the insulation Parts contributing to the safety of the product must not be damaged or obviously unsuitable This is valid especially for insulators and insulating parts Thermally loaded solder pads are to be sucked off and re soldered Ensure that the ventilation slots are not obstructed Potentials as high as 25 KV are present when this re ceiver is operating Operation of the receiver outside the cabinet or with back cover removed invol ve a shock hazard from the receiver Servicing should not be attempted by anyone who is not thoroughly familiar with the precautions necessary when working on high voltage equipment Perfectly discharge the high potential of the picture tube before handling the tube The picture tube is highl
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