Matsui 1410T, 2010R Service Manual

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SERVICE MANUAL

MATSUI 1410R/1410T/2010R

Version 1.1

Mastercare, Maylands Avenue, Hemel Hempstead, Hertfordshire, HP2 7TG, Telephone 01442 888104

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MATSUI 1410R/1410T/2010R

PRODUCED BY

MASTERCARE TECHNICAL CENTRE

SERVICE MANUAL

Specifications are subject to change without notice.

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Contents

Technical Specifications Page 2 Mechanical Instructions Page 3 Overview oscillograms / testpoints Page 4 Descriptions of microprocessor and TXT in CTN chassis Page 5 Small signal Page 7 Power supply Page 9 Power supply signal Page 10 Electrical Adjustments Page 11 Repair Facilities Page 12 Block Diagram Power Supply Page 13 List of Abbreviations Page 14 Electrical Instructions Page 15 Safety Instructions, Maintenance Instructions, Warnings and notes Page 17 PCB layout Page 18 Block Diagrams Page 20 Circuit Descriptions Page 26 Parts List Page 33

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Technical specifications

CHASSIS CTN

Mains voltage : 220 - 240 V ± 10% AC; 50 Hz (±5%) Power cons. at 220V~ : 35 W (stand-by 6W) Aerial input impedance: 75Ohms - coax Min. aerial input VHF : 30:V Min. aerial input UHF : 40:V Max. aerial input VHF/UHF : 180mV Pull-in range colour sync. : ± 300 Hz Pull-in range horizontal sync. : ± 600 Hz Pull-in range vertical sync. : ± 5 Hz Picture tube range : 14''

: Mono 4'' round full range 25W 1W.

TV Systems : PAL BG

: PAL I : PAL BG / SECAM BGDK : PAL BGI / SECAM BGLL'

Indications : On screen display (OSD) green and menu

: 1 LED (red in ON and blinking red in stand-by) VCR programs : 0 to 79 Tuning and operating system : VST UV1315AS / IEC (VST) : VHFa: 48 - 102 MHz

: VHFb: 138 - 224 MHz

: UHF: 470 - 861 MHz U1343AS / IEC (VST) : UHF: 470 - 861 MHz Local operating functions : Vol/Prog, +, -, contrast, colour and brightness.

2. Connection facilities

Euroconector:

1 - Audio

R (0V5 RMS ó 1K ). 17 - CVBS

2 - Audio

R (0V2 - 2V RMS ò 10K ). 18 - CVBS

3 - Audio

L ( 0V5 RMS ó 1K ). 19 - CVBS

( 1Vpp 75W ).

4 - Audio

20 - CVBS

( 1Vpp/75W ).

5 - Blue

21 -

Earthscreen.

6 - Audio

L (0V2 - 2V RMS ò 10K ). 7 - Blue (0V7pp/75W ). 8 - CVBS status 1

(0-2V int., 10-12V ext.). 9 - Green

10 - -

11 -

Green

(0V7

/75W ). 12 - 13 - Red

Head phone:

14 - 15 - Red (0V7

/75W ). 8 - 600

/60mW 3,5mm

16 - RGB status (0-V4 int.) (1-3V ext. 75W ).

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Fig. 3.1

Fig. 3.2

For the main carrier two service positions are possible (3.1).

A: For faultfinding on the component side of the main carrier. B: For (de) soldering activities on the copper side of the main carrier.

Position A can be reached by first removing the mains cord from it's fixation, then loosen the carrier lips (1) and then pulling the carrier panel (2) for approximately 10cm.

Position B can be reached from position A after disconnecting the degaussing cable. Put the carrier on the line transformer side.

Mechanical instructions

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Overview oscillograms / Testpoints

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MICROPROCESSOR + TXT The CTN model chassis is designed to accept three different microcontrollers: the TMP47C634, the SAA5288 and the SAA5290. The three microcontrollers are mounted in the same position, by placing pin 1 at the same point. The TMP47C634 has 42 pins while the SAA52XX

models have 52 pins. The circuitry connected to the pins is practically the same. From pin 21 on the Toshiba model, the equivalent pin on the SAA52XX unit will be 10 numbers higher (e.g., pin 33 on the TMP47C634 corresponds to pin 43 on the SAA52XX).

The difference between the TMP47C634 and the SAA52XX is an improvement in the OSD (it goes from two lines to a full screen, thus making it possible to implement the MENU) and the addition of new functions in the software (24-h timer, child block, etc.). The SAA5290 also has a TXT decoder. Following is an explanation of the different functions of the microcontrollers with indications as to the pin n umber assigned to each integ rated circuit and the differences between the microprocessors, where applicable:

- Integrated circuit power supply: The TMP47C634 has a single +5V power supply (pin 42 VVD). The SAA52XX has several power supplies for the microcontroller (pin 44 VDDM), the analog converter and the OSD (VDDA pin 38 and VDDT pin 39), as well as for the final phase of RGB outputs (RGBREF pin 31).

- LED (pin 20): The LED lights up with a low current when the television set is ON and with a high current when the set is on Standby.

- RC5 (pin 35 on the TMP47C634; pin 45 on the SAA52XX): The commands transmitted by the remote control handset are received by infrared receiver 1685 and passed to the microcontroller for decoding.

- Switching voltages of the BG/L-L/L’-BG/I systems (pins 36, 37 and 38 on the TMP47C634; pins 46, 47 and 48 on the SAA52XX). Th ese signals are only used on Multistandard units. These pins are used for switching the system for decoding sound and video. These signals are inverted and set at the correct level by transistors 7672 and 7673, respectiv ely. Once they are transf ormed, together with the signal from pin 48 (BG/I), they make up the system status lines (See table).

- Oscillator: The TMP47C634 has a 4-MHz oscillator which is determined by a 4-MHz ceramic resonator on pins 31 and 32. The SAA52XX has a 12MHz oscillator which is determined by a 12-MHz crystal between pins 41 and 42.

- On-Screen Display (OSD): In order to synchronize the OSD information with the picture signal, the VERT FLYBACK signal is added in inverted form to the integrated circuit (pins 15 and 27 on the TMP47C634 and pin 37 on the SAA52XX), as is the HOR FLYBACK signal (pin 26 on the TMP47C634 and pin 36 on the SAA52XX). The SAA5290 also uses these signals to synchronize the TXT. On the TMP47C634 there is an LC network on pins 28 and 29 which controls the OSD. The TMP47C634 has only the green output activated (pin 23) and this is inverted with transistor 7658 so that the correct level is reached. The SAA52XX models have three outputs, R, G and B (pins 32, 33 and 34) with emitter followers (7641, 7642 and 7644). The pin for erasing the RGB picture signal for inserting OSD (pin 25 on the Toshiba and 35 on the SAA52XX) is connected with diode 6679 to pin 21 on the TDA836X.

- Tuning: The unit has a VST (Voltage Synthesized tuning) system. This system wor ks by tuning to a station on the tuner through a linear variation of the tuning voltage (0V2 to 5V). It is a vailable on pin 1 of the mC and converted to an adequate level on the selector/dial (0V to 33V), using T7605 and +101.5V. The AFC signal (Automatic Frequency Control) of detector FI is added to the tuning voltage V-VARI by R3689 and R3688 to compensate for the slow variation of the tuning feature. While searching for the station, pin 41 is set on high which means that the AFC voltage will not be added to the V-VARI. If an IDENT signal is received on pin 16 while searching for a station, the mC will check via entry pin 9 whether the tuning is correct and whether the AFC signal can be activated again. The SAA52XX has 3 pins (15 VHF1, 17 VHFIII AND 18 UHF) for band switching and provides v oltage to the corresponding pin. The TMP47C634 has only two pins (17, 18) for band switching which decode the 3 tuning lines using transistors 7003 and 7004. The SAA52XX models also have pin 30, which they use to limit the CAS voltage in automatic tuning so that noise signals are not memorized.

- Picture and sound adjustments: volume control (pin 2), brightness control (pin 3), colour control (pin 4) and contrast control (pin 5); the SAA52XX models also have sharpness control (pin 6).

Description of microprocessor and TXT in CTN chassis

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The RC networks are used to convert the modulated pulse output to a DC voltage level. Some of these settings can be preprogrammed in the memory for all channels as a personal preference (PP). Mute is controlled internally on the mC during automatic station search or when the signal received is interrupted (detected via the IDENT signal on pin 16).

- Service: If pin 7 is connected to earth when the set is tur ned on from the IR, the unit will go into Service Default Mode (see Chapter 8).

- INT/EXT and mute on programme 0. The microcontrollers ha v e a pin for switching to e xternal (pin 7 on the TMP47C634 and pin 8 on the SAA5290) via transistors 7876 and 7877. This signal is added to the signal from SCART pin 8 so that either of them can be used to switch to external. On units without SCART, this signal is used for muting the sound and picture on programme 0. On the SAA52XX models, this line is also an input line so that the microcontroller knows if the unit is on external. This way, the correct video signal is switched on the TXT and the sound is not muted on external, even if there is no pilot signal.

- EEPROM bus 12C memory (pins 39 and 40 on the TMP47C634; pins 49 and 50 on the SAA52XX); The microcontroller is connected to non-volatile memory IC7685 (EEPROM) via bus 12C. Personal preferences (PP) and channel data are stored in the memory. The system can memorize 79 channels (with the data on tuning voltage, band and system) and the personal preferences.

- Standby (pin 19); The Standby switching signal is on pin 19 of the mC . If the Standby signal is “low”, it reduces the start-up voltage of oscillator pin 36 on the TDA836X, thus cutting the line voltages.

- Control and options keypad; The decoding principle is different depending on the unit. On the TMP47C634, it decodes a matr ix between pins 11, 12 and 13 while on the SAA52XX, it only checks to see if the pin is earthed. The TMP47C634 also checks for diodes 6603, 6604 and 6605 via pin 14 on the microcontroller (see options table on diagram). The SAA52XX reads the options via pins 14 and 52, which will be “1” or “0” depending on the components (2690, 3600, 3650 and 3657).

- TXT: The SAA5290 has an internal teletext decoder. The following functions have been programmed on the software: TXT input/output, show, freeze, temporary cancellation, clock, subcode, zoom, index, flof , page +/-, X/26 and 8/30 pac k et decoding (station identification and start-up page). Synchronization is received from the HOR FLY and VERT FLY signals, as is the OSD (this means that if the video signal is lost, the TXT does not become unsynchronized). The teletext information is extracted from the video signal inserted on pins 23 (internal video) and 24 (external video) via condensers 2635 and 2636. Pin 27 corresponds to the NIL control signal, which pulse switches transistor 7640 and keeps the picture from interlacing when applied to the vertical deflector. All remaining circuitry (oscillator, RGB output, fastblanking, etc.) is shared with the microcontroller.

SYSTEM L/L' BG/L

LLL

LLH

LLL

LHL

HHL

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Small signal

IC 7015 (TDA836X) is a single-chip video processor with built in IF- detector, luminance and chrominance separator, PAL chroma decoder, RGB processing , horitzontal&vertical syn. processor, FM sound- decoder,

IF (INTERMEDIATE FRECUENCY) DEMODULATION (ic7015/6A)

IC 7015/6A contains the IF detector. The 38.9 MHz IF signal is a present at the output pin 11 of the tuner (33.4 MHz for a sign al according to the SECAM L' system). Bandpass filter; The IF bandpass characteristic is determinated by the bandpass of the SAW (Surface Acoustic Wave) filter 1015. * For PAL BG sets a SAW filter with 5.5 MHz bandwich is used (33.4 to 38.9 MHz). * For PAL I sets a SAW filter with a bandwinch of 6.0 MHz is used (33.4 to 39.4 MHz). * For PAL BGI/SECAM BGLL' sets a SAW filter with 6.0 MHz bandwich is used to enable BGILL' reception. * For LL' reception BG/L is "high", D6014 conducts and so the 33.4 MHz is tuned to a lower frecuency with C2014 (32.9 to 38.9 MHz). * For BGIDK reception BG/L is "low", D6014 does no conduct. With C2013 the bandpass filter is tuned at 33.4 MHz (32.4 to 38.9

MHz).

* For PAL BG/SECAM BGDK sets a SAW filter with a bandwich of 6.5 MHz is used without switching possibilities (32.4 to 38.9

MHz).

Demodulation and AGC; After the bandpass filter the IF signal is supplied to the IF-detector IC7015/6A pins 45 and 46. This IC7015 6A is suitable for a both negative (BGIDK) and positiv e (LL') modulation controlled by the BG/L switching signal (" high" for LL' positive modulation, "low" for a BGDIK negative modulation) at pin 1 IC7015/6F (pin 1 IC7015/6F is at DC level input pin for positive/negative switching of IC7015/6A). This control also determinates whether the AGC circuit controls at the top white lev el (positiv e modulation) or at the top sync level (negative modulation). The high-frecuency AGC voltage is available at pin 47. The take over level of the high-frecuency (delayed) AGC control can be set at pin 49 by means of R3021. For switching to diferent IF for the SECAM L' system (33.4 MHz) the demodulation reference circuit 5040 at pins 2 and 3 IC7015/6A is switched by switching signal L/L'. * For BGILDK reception L/L' is "low", D6042 conduct and so coil 5043 is connected in parallel to 5040. The circuit is tuned to 38.9

MHz.

* For reception L/L' is "high", D6042 does nor conduct. The circuit is tuned to 33.4 Mhz by L5040 only.

Note: For sets with LL' reception L5040 is tuned at 33.4 MHz, for sets without LL' reception L5040 is tuned at 38.9 MHz (or 39.5 MHz for PAL I only sets). Automatic Frecuency Control (AFC) signal at pin 44 is obtained from the reference signal of the IF-detector and the control is modified internally in IC7015/6A for positive or negative modulation. C2037 smoothes the AFC voltage.

SOURCE SELECT, LUMINANCE AND CHROMINANCE SEPARATION (IC7015/6B)

Sound trap; The baseband CVBS signal of pin 7 IC7015/6A (nominal amplitude of 2Vpp) also contains the 5.5 or 6.0 MHz FM sound signal (FM intercarrier sound). This sound signal is filtered out with a 5.5 MHz (6.0 MHz PAL I) ceramic filter (1032 and/or 1033). Source select: The CVBS signal is now fed to pin 13 IC7015/6B to the source selector switch in IC7015/6B. Pin INT/EXT = 0V gives internal CVBS (pin 13), pin 16 INT/EXT = 8V gives external CVBS (pin 15) (external signal SCART CVBS IN from the CVBS IN cinch or pin 20 scart-connector). Luminance and chrominance separation: chrominance signal is filtered out (-20dB) by a luminance notch filter which is internallly calibrated at the subcarrier frecuency (4.43 or 3.58). The IDENT status signal is coming from pin 14 IC7015/6B. In case of no horizontal sync (so no signal detected) by the sync processor IC7015/6E, pin 14 IC7015/6B is made "low", TS7651 does not conduct so pin 16 of the µC is "high". The IDENT signal is internally fed to ensuring stable OSD even without transmiter signal (IC7015/6D can be switched to different time constants).

CHROMINANCE DECODING (IC7015/6C)

CVBS is extracted from the baseband CVBS signal from the IF-detector via crystals 1032. PAL (and NTSC if applicable) chroma decoding inside IC7015/6C, SECAM chroma decoding inside IC7250. Inside IC7015/6C the PAL (or NTSC) chroma signal is fed via amplification and a burst demodulator to the R-Y and B-Y demodulator. (PAL or NTSC processing is determined automatically by the burst demodulator inside IC7015/6C). The 4.43 MHz reference crystal for chrominance demodulation in IC7015/6Cis in present at pin 35 of IC7015/6C. Pin 27 shoud be 5V5 (via R3280) to force IC7015 in the PAL/SECAM mode; by then IC7015/6C is in the PAL decoding mode and via pin 27 feeds throught the chroma signal to the SECAM chroma decoder IC7250 (so IC7015/6C searches for PAL and IC7250 searches for SECAM). Via a

bidirectional communication line between pin 32 of IC7015/6C and pin of IC7250 both IC7015/6C and IC7250 "know" wether

a PAL or a SECAM signal is detected:

- On AC level there is a

4,43 calibration for calibration of thr PLL and chroma cloche filter of IC7250.

- On DC level there is a SECAM or PAL switching line enabling automatic selection of IC7015/6C and IC7250 to supply R-Y and BY to the delay line IC7271.

* If IC7015/6C has detected a PAL signal,

Vpin 32 is made 1V5. By then the demodulated R-Y and B-Y at output pins 30 and 31 od

IC7015 / 6C are fed to delay line IC7271.

* If IC7015/6C has detected a PAL signal, Vpin 32 is made 5V. By then the demodulated R-Y and B-Y at output pins 30 and 31 of

IC7015/6C are not fed to the delay line IC7271.

* If IC7250 has detected SECAM

Vpin 1 IC7250 becomes "low", sinking typical 150 µA from the 5V from pin 32 IC7015/6C. Only in case the sinking current at pin 32 IC7015/6C is typical 150 µA, only by then IC7015/6C "knows" IC7250 has detected SECAM demodulated R-Y and B-Y are fed to the delay line IC7271 via output pins 9 and 10 of IC7250.

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RGB DEMATRIXING (IC7015/6D)

RGB-dematrixing dematrixies the -(R-Y), -(B-Y) and the Y signals; the sandcastle pulse coming from the IC7015/6E synchronises RGB dematrixing and suppresses the RGB signals during line and frame flyback. Control by µC for contrast, brightness and saturation (0V5 to 4V5). RGB-source select switches between internal RGB and external RGB (OSD or SACART) via pin 21 of IC7015/6D (via resp OSD FAST BLANKING from OSD generator and FAST BLANKING from SACART or µP INT/EXT from µC).

HORIZONTAL SYNCHRONISATION (IC7015/6E) diagram B

Start up of the hor. oscillator via +11A giv es start up current into pin 36 5V8 the hor. oscillator starts running approx. 25 KHz and only when IC7015 supply pin 10 = 8V the line frecuency changes to 15625 Hz. Hor, sync., separator separates hor pulses out of CVBS and so synchronises the free-running hor. sawtooth generator. Both the line and frame frecuencies are internally locked to the chroma oscillator on pin 35 IC7015/6C. Hor, oscillator sawtooth is converted in square wave voltage with variable duty cycle (pin 37). Hor, flyback pulse at pin 38 compares phase of flyback pulse with phase of the hor. oscillator ; if phase not correct the duty cycle of hor. oscillator will be adjusted. Time connstant of the sync. circuit automacallly determinated by IC7015/6E. Pin 38 is both sandcastle output and hor. flyback input. Selection automacally determinated by the input current (sandcastle a few µA, flyback 100-300 µA determinate by R3371). Amplitudes of sandcastle pulse; burst 5V3, line blanking is 3V, frame blanking 2V. At standby (STANDBY "low") TS7580 blocks and TS7581 conducts and so the line is shut down at stand by.

VERTICAL (VERT.) SYNCHRONISATION (IC7015/6E) diagram B

Vert. sync. separator separates frame sync. pulses from CVBS and so synchronises frame oscillator. IC7015/6E compares phase of flyback pulse with phase of sawtooth at pin 42 (from external RC network); if phase not correct the duty cycle of hor. Pre-amplifier in IC7015/6E amplifies sawtooth (pin 43 of IC7015/6).

Via BCI' frame correction is realised for high beam currents; If beam current increases (more white), EHT decreases so picture will become too big. BCI and so BCI' decrases for increasing beam current (diagram C) and the picture will be corrected.

SOUND DETECTION (IC7015/6F) diagram D

There are two audio paths: for the BG, I and DK systems FM modulated intercarrier sound (sound extracted from baseband CVBS from IF detector), for the LL' systems AM modulated quasi-split sound (sound extracted directly from the tunner). FM demodulation; For FM modulated sound the sound signal is filtered throught filter 1135 or 1136 from the baseband picture signal. For BGDK or BGILL' sets the switching signal BG/I is used to select the current crystals. * For I (or DK) reception BG/I is "low", TS7170 does not conduct, D6170 conduct and so crystal 1136 (6.0 MHz for I and 6.5 MHz for

DK) is switched parallel to 1135.

* For BG reception BG/I is "high", TS7170 conduct, D6170 does not conduct and 1136 is not switched in parallel to 1135 (5.5 MHz

only).

* For PAL BG or PAL I only sets only 1135 is used (resp. 5.5 MHz or 6.0 Mhz). FM-mono sound demodulation takes place in

IC7015.6F. No adjustament required for BG or I demodulation as automatic PLL tuning (4.2 to 6.8 MHz). Sound frecuency characteristic is defined by de-emphasis C2112 at pin 1. Volume control on DC level at pin 5. Selection between

FM sound or AM sound/EXT sound (from input pin 6) by pin 16 IC7015/6B. AM demodulation; Interferences signals at 30,9 MHz are removed from IF signal coming fron tuner by SAW filter 1137 (double band pass caracteristic) the required frequency spectrum is fed to the AM demodulation IC7125. The doble characteristic is necessary because for the L system the sound is at 32,4 MHz and for L´at 39,9 switched by switching signal L/L´and TS 7126 TS7127 * For L´ reception (L/L´ is "high") IF signal is present in pin 2. * For L reception (L/L´ is "low") IF signal is present in pin 1. The demodulated signal at pin 6 of IC7125 is supplier to the source selection switch in IC7140 , C2126 and 2127 are AGC related storage capacitos. Source selection: INT/EXT is "low " for internal and "high" for external . This signal is made from uP INT/EXT and pin 8 of the scart. If one of these 2 signals is "high" external is selected. BG/L is "low" for FM sound (BGIDK) and "high" for AM sound (LL'). * Top switch in IC7140 select between AM sound (pin 5) and EXT sound from SCART +AV (pin3) by pin 9 INT/EXT. The output of this

selector (pin 4 IC7150 ) is fed to input pin 6 of FM demodulator IC7015/6F .

Here selection is made between FM sound (pin 5) and EXT sound from SCART+ AV (pin 3) by pin 9 INT/EXT. The output of this

selector (pin 4 IC7150) is fed to input pin 6 of FM demodulator IC7015/6F. * Middle switch in IC7140 selects between AM (pin 1) and FM sound (pin 2) for SCART AUDIO OUT by pin 10 (BG/L is "high" f or AM

pin1, "low" for FM pin2). * Bottom switch in IC7140 connects +8 to pin 1 IC7015/6F to switch the IF-detector and A GC (both IC7015/6A) to positiv e modulati on

for SECAM LL´(BG/L so pin 11 IC7140 is "high" for AM LL´ positive modulation so pin 13 to +8). Anti-plop; At switch on the set C2183 is not charged, anode C2183 is "high", TS7183 conducts and so mutes the output amplifier IC7187. As soon as C2183 is charged anode C2183 is "low", TS7183 stops muting. At switch off of the set the +8A drops very fast. As C2183 is still charged, the anode of C2183 becomes approx. -8V DC. By then the DC volume control signal VOLUME is shorted via zener D6183, so IC7015/6F is muted.

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Power Supply

Mains isolated switched mode power supply (SMPS), control IC7514 (TD A4605) gives oscillation, variable frequency, variable duty cycle, switching FET, no opto coupler, no thrystor switching windings on the secondary side, slow start circuitr y and no standby mode of the power supply. Via sense windings 4-2 frequency and duty cycle control on the primary side. Duty cycle and frequency of the power depends on T-on of FET TS7525 which is controlled by IC7514. This IC detects variations of the +100 (at the secondary side of 5525 at winding 5-7) via sensing windings 4-2 at the primar y side of 5525. The switching period of TS7525 is divided in three main areas T-on, T-off and T-dead: During T-on energy is extracted from the mains into the primary winding 8-12 of transformer 5525 with a linear increasing primary current (slope depends on voltage across C2505). Via T-on regulation the duty cycle and the frequency of the SMPS and so the +100 can be controlled. During T-off energy "inside" transformer is supplied to the load via secondary windings of 5525. Current through secondary side of the transformer decreases linear with firm slope. During T-dead no energy is extracted or supplied. During T-dead the L-prim is demagnetised (polarity L-prim and C2524 is switched).

PRIMARY SIDE

Degaussing; R3501 is a dual PTC (2 PTC's in one housing). After switch on set, PTC is cold so low-ohmic and so degaussing current is very high. After degaussing, PTC is heated so high-ohmic, so in normal operation degaussing current very low. Mains voltage is filtered by L5500, full wave rectified by diodes 6502-6505 and smoothed by C2505 to VIN (300 V DC for 220V AC mains). Start up; Via start up circuitry via R3507 the DC voltage VIN is used to start up IC7514. As soon as the supply voltage Vpin6 12V the IC7514 starts; the internal oscillator of IC7514 drives TS7525 into conduction at the lowest frequency (during start up C2523 determines the frequency; as C2523 is uncharged at start up this gives a low start). The power supply automatically starts up. Take over IC7514; During start up a voltage across winding 4-2 is built up. At the moment the voltage across winding 4-2 reaches approx. +15V, D6521 star ts conducting and takes over the +15 supply voltage at pin 6 IC7514.

CONTROL CIRCUITRY

+100 feedback for frequency and duty cycle control; Sense windings 4-2 has same polarity as winding 5-7. During T-off winding 57 and so winding 4-2 are positive. D6515 conducts and so charges C2515; the DC level across C2515 is a reference for the +100. Via R3518, R3517 and R3508 this DC-voltage is brought to the required level for input pin 1 IC7514; this voltage is used for frequency and duty cycle control of IC7514. R3518 is a potentiometer and so +100 can be adjusted. IC7514 controls +100 by controlling T-on and so the frequency and the duty cycle; IC7514 compares v oltage at pin 1 with an internal reference voltage. * In a stable situation the voltage at pin 1 is the same as the internal reference voltage, so frequency and duty cycle remains the

same. * If +100 increases the voltage at pin 1 increases, and so the frequency and duty cycle and so the +100 will be decreased (new

balance of voltage at pin 1 and the reference voltage and so new lower stable frequency and duty cycle). * If +100 decreases, the voltage at pin 1 decreases. The frequency and duty cycle and so the +100 will be increased. The voltage at pin 1 is in a stable situation typical 400 mV. Undervoltage protection; If Vpin6 supply voltage drops under 7V25, the logic in IC7514 will shut the output at pin 5. The power supply will stop running. Overvoltage protection; The power at pin 3 IC7515 is a measure for the mains voltage and so the DC Vin across C2505. As soon as the voltage Vpin3 6V6, the logic in IC7514 will shut the output at pin 5. The power supply will stop running. Overload protection; If the secondary load becomes too high, the T-on becomes too long. The internal sawtooth used for oscillation is measured over C2509 at pin 2 IC7514. If Vpin2 3V (foldback point) the IC will switch into overload mode giving protection (hickup or burst mode): IC7514 switches TS7525 and so power supply "off" as long as I-prim is too high, starts up again, if I-prim still too high switches "off" again, etc.

SECONDARY SIDE

±100 for the line output stage ±100A for the tunning (V VARI), +11 for sound output amplifier, +11A for start up of the line circuitry, ±5 for pull up and +5A for µC and EEPROM. No secondar y protections are available.

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Power supply signals

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Electrical adjustments

Adjuntaments on the main panel (fig.7.2).

1.1. +100V power supply voltage.

Connect a voltmeter (DC) across C2530. Adjust R3518 for a voltage of +101V5 f or 14" or +106V5 for 20" sets at back picture (beam current 0 mA).

1.2. Horizontal centring.

Is adjusted with potenciometer R3354.

1.3. Picture height.

Is adjusted with potenciometer R3410.

1.4. Focussing.

Is adjudted with potenciometer in the line output transformer.

1.5. If filter (only for sets with SECAM LL' reception

possibility).

Connect a signal genetor (e. g. PM5326) viaa capacitor 5p6 to pin 17 of the tunner an adjust the frequency for 33.4 MHz. Connect an osciloscope to pin 1 of filter 1015. Switch on the set and select a program with system Europe (BG/L "low" for BGIDK reception). Adjust L5040 for a minimum amplitude.

1.6. AFC.

a. For a sets

with SECAM LL' reception possibility: Connect a signal generator (e. g. PM5326) as indicated in point 1.5. Connect a v olmeter to pin 44 of IC7015/6A.

Adjust the frecuency for 38.4 MHz and a select a program with system France (L/L' is "higt" for reception).

Adjust L5040 for 3V5 (DC). Next adjust the frecuency for 38.9 MHz. Select a program Europe (L/L' is "low" for BG- ILDK reception). Adjust L5043 for 3V5 (DC).

b. For sets without SECAM LL' reception possibility: Connect a signal generator (e. g. PM5326) as indicated above and adjust the frecuency for 38.9 MHz (for a PAL I at 39.5 MHz). Connect a voltmeter to pin 44 of IC7015/6A. Adjust L5043 for 3V5 (DC).

1.7. RF AGC.

If the picture of a strong local transmiter is reproduced distorted, adjust potenciometer R3021 until the picture is undistorted.

Or: Connect a pattern generator (e. g. PM5518) to the aerial amplitude=1mV. Connect a multimeter (DC) at pin 5 of tunner. Adjust R3021 so that voltage at a pin 5 of tuner is 3V7 ±0V5(DC).

2. Adjustaments on the CRT panel (Fig. 7.1).

2.1. Vg2 cut-off points of picture tube.

Apply a pattern generator (e. g. PM5518) and a set it to a white raster pattern. Adjust contrast and Vg2 at minimum (Vg2 with potentiometer in the line output transformer to the left). Adjust brightness until the DC voltage across potentiometer 3213 is 0V. Adjust R3207 (B), R3220 (G) and R3234 (R) for a black le vel of 115V on the collectors of transistors 7205, 7218 and 7227. Adjust Vg2 potentiomete until the gun that first emits ligth is just no longer visible. Adjust the two other guns with the respective controls (3207 3220 or 3234) until just no light will be visible.

2.2. Grey sacle (white D).

Apply a test pattern signal and the set for normal operation. Allow the set to warm up for about 10 minutes. Adjust R3213 and R3214 until the desired grey scale has been obtained.

FIG. 7.1

Page 14

FIG.7.2

Error messages

The microcomputer also detects errors in circuits connected to the I2C (Inter IC) bus. These error messages are communicated via OSD (On Screen Display) and a flashing LED.

Note: After replacing the microcomputer first solder the shielding before testing the set. This is needed as the shielding is used for earth connection. If this is not done the set can switch into protection mode (see description of the SMPS).

Repair facilities

Test points

The CTN chasis is equipped with test points, TP1, TP2, etc in the service printing on the component side of the monoboard. Using these test points it is possible to set a quick diagnosis on the top of the monoboard.

Functional blocks

On both the service printing on the copper and the component side, functional blocks are given. These blocks indicate the functionaly of that specific part of the circuit.

Service Default Mode

The CTN software contains a "Service Default Mode" . To activate this mode the service pin of the microcomputer (pin 7-IC7600) should be short-circuited to ear th while switching on the set with the mains switch (shorting pin 7 can be done on the copper side via the 2 copper squares or on the component side by pin 7 and the shielding of the µC) When the set in the Service Default Mode and "S" appears on the screen. In the Service Default Mode the set is in a pre-defined mode In this mode all analog settings (volume, contrast, brighness and saturation) are in the mid position and the set is tuned to program number 1. The Service Default Mode is left via switching off the set by the mains switch or via standby on the remote control.

Error Error Possible defect-

message description tive component

F1 en OSD y Error interno µC IC7600

LED parpadea

F2 en OSD y Error Eeprom IC7685

LED parpadea

Page 15

Block diagram power supply

+100

+10V

Page 16

List of abbreviations

µC Microcomputer µP INT/EXT Switching signal from µC to TS7876 and TS7877 (diagram C) making together with pin 8 of SCART connector the INT/EXT s witching signal; "low" for

internal, "high" for external AF Alternating Current AFC Automatic Frecuency Control AGC Automatic Gain Control AM Amplitude modulation AQUA Aquadag on the CRT panel for spark gaps and used for making BCI signal AV Audio and Video cinches on the rear side of the set BCI Beam Current Info; if beam current increases the BCI signal decrases. BCI is used for contrast reduction if beam current is too high BCI' Derived from BCI; if beam current increases (more white), EHT decreases so picture will become too big. BCI and so BCI' decreases for increasing

beam current (diagram C) and the picture will be corrected. BG/I Switching signal from µC; "low" for I or DK reception (6.0 or 6.5 MHZ FM sound), "high" for BG reception (5.5 MHZ FM sound) BG/I/DK/LL' Sond system BG/I/DK/LL' indicate frecuency distance between sound and picture carriers (5.5 MHz for I, 6.5 MHz for DK and LL') BG/L

Switching signal from µC; "low" for BGIDK reception (negative modulation, FM sound), "high" for LL' reception (positive modulation, AM sound)

BRI Brightness control signal (same as BRIGHTNESS) BRIGHTNESS Control signal (from µC, but on DC level via RC network) for brightness control of the video controller IC7015/6D BSW1 Bandswitcing signal from µC to 2 to 3 decorer IC 7002 BSW2 Bandswitching signal from µC to 2 to 3 decorer IC7002 CONTRAST Control signal (from µC, but on DC level via RC network) for brightness control of the video controller IC7015/6D CRT Picture tube CVS Colour Video Blanking Synchronisation from pin 7 IF detector IC7015/6A DC Direct current EEPROM Electrical Eresable Programmable Read Only Memory EHT Extra High Tension (25 KV) FET Field Effect Transistor FF Filatement (heather voltage) FM Frecuency MOdulation HOR FLYBACK Horizontal flyback pulse (15625 Hz) used for locking the horizontal oscillator in IC7015/6E and for locking the OSD generator in the µC HOR Hor izontal drive signal from IC7015/6E to line output stage HUE Tint ajustment for NTSC system I

C Digital Control bus of the microcomputer IDENT Status signal; "low" for horizontal synchronisation, "high" in case horizantal synchronisation is detected IF Intermediate Frecuency iNT/EXT Switching signal derived fromµµP INT/EXT and pin 8 of SCART to pin 16 IC7015/6B and IC7140 (diagram D); "low" for internal, "high" for external L/L' Switching signal from µC; "low" for BGIDKL (picture at 38.9 MHz) reception, "high" for L' reception (picture at 33.4 MHz) LED Light Emitting Diode LOT Line Output Transformer MUTE PROG 0 Only for sets whithout SCART + AV ; "low" for program 0 muting the sound, "high" for program 1-39 NIL Non InterLace NTSC National Television System Committee OSD On Screen Display OSD FAST BLANKING Fast blanking info from OSD generator in µC to video controller IC7015/6D for blanking the RGB info to enable OSD-G insertion OSD-G Green info from OSD generator in µC to video controller IC7015 for inserting green OSD info on screen. PAL Phase Alter nating Lines PLL Phase Locked Loop POR Power On Reset (ensures the µC starts up it's software only if the power supply of the µC itself is high enough) POS/NEG Switching signal from IC7140 via BG/L; "high" for positive modulation (LL'), highihmic for negative modulation (BGIDK). PP Personal Preference PROT Prottection signal from frame IC7400; in case vertical flyback generator in IC7400 is not activted, the voltage at pin 8 IC7400 becomes 2V.

Protection circuit in IC7400 will make pin 7 "high" overrulling the HOR FLYBACK and SANDCASTLE. The constant "high" sandcastle is supplied to

the luminance circuit and so the picture will be blanked. PTC Positive Temperature Coefficient Resistor RC5 Remote Control 5 system RGB Red Green Blue ROM Random Access Memory SATURATION Control signal (from µC, but on DC level via RC network) for saturation control of the video controller IC7015/6D SAW Surface Acoustic Wave; very precise bandpass filter. SC Sandcastle signal from IC7015/6F to delay line IC7271 and SECAM chroma decoder IC7250 SCART CVBS IN CVBS signal from pin 2 SCART to external input pin 15 IC7015/6B SCART CVBS OUT CVBS signal from IF detector IC 7015/6A to pin 19 SCART SCART AUDIO IN Audio signal from SCART + AV cinches to source select IC7140 SCART AUDIO OUT Audio signal from IC 7140 to pin 1 and 3 SCART + AV SCART Euroconnector SCL Clock line of the I²C-bus SDA Data line of the I²C-bus SDM Service Default Mode; predefined mode for faultfinding (see chapter 8) SECAM SEquential Couleur A Memoire SMPS Switched Mode Power Suplly STANDBY Switching signal; "low" for standby (only line is shut), "high" for normal operation SYNC Synchronisation TP-1 Tets point 1 UHF Ultra High Frecuency band from tuning range V-IN The DC voltage across C2505 present at pin 11 of the primary side of the transformer V-VARI Tuning voltage (0-30V) VERT FEEDBLACK 50Hz vertical flyback pulse used for locking the vertical oscillator in IC7015/6E VERT FLYBACK 50Hz vertical flyback pulse from frame IC7400 lo lock the OSD generator in µC VERT DRIVE Vertical drive signal from IC7415/6E to frame amplifier IC7400 Vg2 Voltage on Grid 2 of the picture tube VHF Very High Frecuency band from tuning range VOLUME Control signal (from µ C, but on DC level via RC network) for volume control of sound processing in IC7015/6F VST Voltage Synthesized Tuning Y Luminance part of video signal

Page 17

Electrical Instructions

A. ADJUSTMENT OF MAIN PLATE

1. Supply voltage: +100V.

Connect a voltmeter (DC) between the +2530 and mass. With potentiometer 3518, adjust voltage to 101V5 for a 14” tube and 106V5 for a 20” or 21” tube.

2. Horizontal centring

Adjust with potentiometer 3354.

3. Picture height

Adjust with potentiometer 3410.

4. Focus adjustment

Adjust with the potentiometer placed on the line transformer.

5. APC

Connect a signal generator (e.g., PM 5326) as indicated in Fig. 1 and adjust the frequency to 38.9 MHz. (PAL I: 39.5 MHz). Connect a voltmeter to pin 44 of IC 7015:C and adjust voltage with 5040 to 3.5V (DC).

6. AGC - RF

When the image of a powerful local TV station is distorted, adjust with potentiometer 3021 until the problem is solved.

B. ADJUSTMENTS ON PICTURE TUBE PANEL

1. Tube cutoff (Voltage Vg 2)

Connect a picture white signal to the antenna. Connect pin 25 of IC7015:E to mass. Adjust the brightness until the DC voltage on potentiometer 3214 is zero. Using potentiometers 3234, 3207 and 3220, adjust the level of black on the collector of transistors 7227, 7205 and 7218 to 125V for a 14” or 21” tube, 130V for a 20” tube. Adjust potentiometer Vg2 until the light from the gun that comes on first is barely visible. Adjust the other two guns with the other controls (3234, 3207 or 3220) until the light disappears.

2. Grey scale

Connect the test signal to the antenna and adjust TV controls as normal. Let the TV warm up for at least 10 minutes. Adjust 3214 and 3213 until the desired grey scale is achieved.

PURITY AND CONVERGENCE ADJUSTMENT

NOTE:

The instructions for adjusting colour purity and convergence de scribed below should be used only if the tube is replaced or when full adjustment is necessary in any other cases. Even when the deflection yoke is replaced, it is not necessary to move the rubber wedges (“G” in Fig. 3). Small corrections can be made using the multipole unit.

I. Colour purity. (Fig. 3)

1. Slightly loosen screw “F” (if CRT has a multipole unit).

2. Move the deflection coil and remove the three rubber wedges (“G”).

3. Slide the deflection coil as far as possible against the tube bulb and

tighten screw “F” so that the deflection coil can be moved with a certain amount of resistance.

4. Position the multipole unit as shown in the diagram, tighten screw

“A” and turn safety ring “B” anticlockwise.

5. Place the TV facing either EAST or WEST and insert tube.

Connect a single crosshatch signal to the antenna and turn up the brightness as high as possible. Let the TV warm up for 10 minutes.

6. Adjust the static convergence using tabs “C” and “D” (see Chapter

II if necessary).

7. Block the green and blue guns by disconnecting resistors 3216

and 3203, respectively.

8. Tur n the colour purity rings with tab “E” so that the vertical red line coincides as closely as possible with the centre of the screen and, at the same time, make sure the centre horizontal line is as cor rectly aligned as possible.

9. Connect a picture white signal and make sure the red vertical line is in the centre of the screen. If it is not in the centre, connect the crosshatch signal again and move the red vertical line in the right direction, making sure that the image does not stray too far from vertical.

10.Connect a picture white signal and move the deflection coil until the inside of the screen is uniformly red.

11.Connect the green and blue guns and make sure that no spots appear on the white screen obtained. If spots appear, they can be corrected by turning rings “E” and/or moving the deflection coil.

12. Tighten screw “F”.

13. Now adjust the static and dynamic convergence.

II. Static convergence (Fig. 3).

(If CRT has a multipole unit)

1. Connect a crosshatch signal and let the TV warm up for 10 minutes.

2. Block the green gun by disconnecting 3216 and turning attachment ring “B” anticlockwise.

3. T urn the 4-pole magnetic rings with tab “C” so that the b lue and red crosshatch pattern is superimposed in the centre of the screen.

4. Connect the green gun and disconnect the blue gun by disconnect ing resistor 3203.

5. Turn the 6-pole magnetic rings with tab “D” so that the red and green crosshatch pattern is superimposed in the centre of the screen.

6. Connect the blue gun and set the multipole unit using ring ”B”.

III. Dynamic convergence

NOTE:

Dynamic convergence is obtained by moving the deflection coil hori zontally and vertically. In order to ensure the exact position of the deflection yoke, three rubber w edges are placed between the glass of the tube bulb and the deflection coil as shown in Fig. 4a or 5d.

1. First adjust colour purity and static convergence.

2. Connect a crosshatch signal and disconnect the green gun by dis connecting resistor 3216.

3. Eliminate the central, horizontal and vertical blue and red lines by moving the deflection coil vertically. If the position of the deflection coil is correct, place the rubber wedge (1) either straight up (Fig. 4a) or straight down (Fig. 5a). The placement of the wedge as in Fig. 4a is correct if the deflection coil is facing down.

4. By moving the deflection coil horizontally, the horizontal red and blue line is superimposed in the top and bottom of the screen and the red and blue vertical line to the left and right. If the position of the deflection coil is correct, place wedges (2) and (3) as shown in Fig. 4b or 5b. Firmly press the adhesive part of the wedge against the tube glass.

5. Now place wedge (4) as in Fig. 4c or 5c and press so that it adheres to the tube.

6. Remove wedge (1) and place it as shown in Fig. 4d or 5d.

7. Connect the green gun.

Page 18

Page 19

FIG. 11.1

Safety Instructions for Repairs

1. Safety regulations require that during a repair:

- The set should be connected to the mains via an isolating transformer.

- Safety components, indicated by the symbol should be replaced by components identical to the original ones

- When replacing the CRT, safety goggles must be worn.

2. Safety regulations require also that after a repair:

- The set should be returned in its original condition.

- The cabinet should be checked for defects to avoid touching, by the customer, of inner parts.

- The insulation of the mains lead should be checked for external damage.

- The mains lead strain relief should be checked on its function

- The cablef orm and EHT cable are routed correctly and fixed with the mounted cable clamps in order to avoid touching of the CRT, hot components or heat sinks

- The electrical resistance between mains plug and the secondary side is checked. This check can be done as follows:

· Unplug the mains cord and connect a wire tween the two pins of the mains plug.

· Switch on the TV with the main switch.

· Measure the resistance value between the pins of the mains

plug and the metal shielding of the tuner or the aerial connection on the set. The reading should be between 4.5 M and 12 M.

· Switch off the TV and remove the wire between the two pins of the mains plug.

· Thermally loaded solder joints should be oldered.

-This includes components like LOT, the line utput transistor, flyback capacitor.

Maintenance Instructions

It is recommended to have a maintenance inspection carried out periodically by a qualified service employee. The interval depends on the usage conditions.

- When the set is used in a living room the recommended interval

is 3 to 5 years. When the set is used in the kitchen or garage this interval is 1 year.

- During the maintenance inspection the above mentioned "safety

instructions for repair" should be caried out. The power supply and deflection circuitry on the chassis, the CRT panel and the neck of the CRT should be cleaned.

Safety instructions, maintenance instructions,

warning and notes

Warnings

1.In order to prevent damage to IC's and transistors any flash-over of

the EHT should be avoided. To prevent damage to the picture tube the method, indicated in Fig. 11.1., has to be applied to discharge the picture tube. Make use of an EHT probe and a universal meter is 0V (after approx 30s).

2. ESD. All IC's and many other semi-conductors are sensitive to electrostatic discharges (ESD). Careless handing during repair can reduce life drastically. When repairing, make sure that you are connected with the same potential as the mass of the set via wrist wrap with resistance. Keep components and tools on the same potential.

3. Proceed with care when testing the EHT section and the picture tube.

4. Never replace any modules or any other parts while the set is switched on.

5. Use plastic instead of metal alignment tools. This willprevent any short circuits and the danger of a circuit becoming unstable.

6. Upon a repair of a transistor or an IC assembly (e.g. a transistor or IC with heatsink and spring) remounting should be carried out in the following order:

1. Mount transistor or IC on heatsink with spring.

2. Resolder the joints.

Notes

1. After replacing the microcomputer first solder the shielding before

testing the set. This is needed as the shielding is used for ear th connection. If this is not done the set can switch into protection mode (see description of the SMPS).

2. Do not use heatsink as ear th reference.

3. The direct voltages and waveforms should be measured relative to

the nearest earthing point on the printed circuit board.

4. The direct voltages and waveforms are measured in the Service Default Mode (see chapter 8). Use a colour bar pattern of a pattern generator (e.g. PM5518).

5. The DC voltages and oscillograms are where necessary measured with ( ) and without ( ) aerial signal (settings as in Service Default Mode; see chapter 8). Voltages and oscillograms in the power supply section have been measured for both normal operation ( ) and in the stand-by mode ( ). As an input signal a colour bar pattern has been used.

6. The picture tube PWB has printed spark gaps. Each spark gap is connected between and electrode of the picture tube and the Aguadog coating.

Page 20

PCB LAYOUT

Page 21

PCB LAYOUT

Page 22

BlocBloc

Bloc

k Diak Dia

k Dia

gramgram

gram

Page 23

3285

75R

2286*

100P

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2284*

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2285* 100P

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3284

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3292*

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9004

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3262* 100K

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2080*

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CVBS

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SCART

WITH

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WITH I

ONLY MULTI

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ONLY MULTI P/S BGLL'

ONLY SECAM

ONLY NO SCART

IDEN

ONLY

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A50

C50

A51

D35

B36

B38

B39

B40

A41

A42

A43

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A42 A43

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SATURATION

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BRIGHT

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C12

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E17

F17

E19

F19

F18

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E18

A18 FAST

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F19

E19 INT/EXT

E20 F20

F21

E21

E25 F25

STANDBY

B37

E47

A47 A49

C48

F16

E16

AFC

A49 E49

AGC

C52A52

INT/EXT

E53

E54

E55

F54

SHARPNESS E60

D61

BSW2 E13 F13

UHF

VHFIII

VHFI

F14

E14

BSW1

E15

BSW3

NO SCART

1001 1015 1032 1033 1272 2001 2002 2003 2005 2006 2007 2011 2013 2014 2015 2016 2017 2018 2019 2022 2025 2030 2034 2037

2043 2044

2041

2045 2050 2053 2080 2081

2262

2082 2084 2261

2265

2273 2274 2275

2272

2267 2268 2271

2279 2280 2284 2285 2286 2291 2292 2293 2297 2340 2350 2351 2354 2366 2370 2371 2850 2852 2860 2871 2876 3001 3002 3003 3004 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023

3030 3031 3032

3029

3033 3043 3044 3045 3051 3080 3260 3261 3262 3272 3273 3275 3280 3284 3285

F7 C4 E3 E4 I5 G5 H7 F6 H8 H8 F2 B4 B4 A4 F5 F5 B5 C5 G1 D6 D5 E2 F4 E2 B2 B2 A2 D3 G3 E5 G4 H5 G4 G4 J5 J5 I6 I3 I3 I1 J2 J2 K1 L1 L3 L3 L4 L4 L5 K6 K6 K6 H1 B9 A8 A8 A7 B9 C8 C8 I8 I8 H7 M8 M8 E6 E7 E7 E8 F8 F8 E9 B4 B3 B4 E6 F9 E8 F8 C5 C5 C5 C5 E6 E5 E6 E3 E2 E3 E3 F4 B2 B2 D2 F5 H5 I5 M3 J5 J1 J1 L1 H4 M4 M4

3286 3289 3290 3291 3292 3340 3341 3342 3345 3351 3353 3354 3370 3371 3372 3850 3851 3852 3853 3854 3855 3858 3860 3862 3865 3875 3876 3879 3880 3881 3882 3883 3884 5001 5002 5010 5012 5015 5032 5040 5043 6001 6003 6014 6020 6042 6261 6275 6289 6372 6849 6850 6851 6852 6853 6854 6855 6865 7001 7003 7004 7015 7016 7030 7250 7271 7875 7876 7877 9001 9002 9003 9005 9012 9015 9016 9017 9020 9021 9034 9035 9043 9051 9080 9115 9124 9261 9262 9265 9271 9289 9331 9350 9354 9366 9367 9370 9371 9372 9600 9810 9811 9812

M5 M5 K5 K5 K5 B8 B8 B9 D7 A7 B7 B7 D7 D8 D8 I8 I7 J8 J7 I9 K7 L7 I7 K7 L7 L8 M8 J8 J9 K8 K8 K9 M7 G6 F6 B5 B3 G2 E3 C2 B2 F7 F8 A3 C5 B2 M3 L1 L5 D8 J6 J7 J7 J7 J7 K7 K7 L7 F6 F9 F8 D4 F1 E2 H2 L2 M8 J9 K9 H9 H8 F6 F6 A4 G9 G2 D7 G3 G3 F2 M9 A2 E5 G5 A4 G3 M3 K6 G2 J3 M5 D7 D7 M1 A8 C8 D7 C7 D8 F6 L9 J9 K9

A B C D E F G H I J K L M

Page 24

156

+8C

3244*

430R

BC858

7211*

+8C

3232*

470R

BC858

7212*

560R

3222*

3224

1K5

+8C

3221*

430R

+8C

470R

3218*

+8C

3208*

430R

RES

2206

9201

3214

2K2

+150V

+8C

BAS32L

6218*

7218

BF422

1K5

3216

12K

3215

+150V+8C

BAS32L

6205*

7205

BF422

1K5

3203

12K

3202

3228

12K

3229

1K5

BF422

7227

6227*

BAS32L

+150V

3211*

1K8

3210*

1K8

3212*

3213

2K2

9202

3226*

3225*

3K3

3227*

+8C

22N

2202*

+8C

3236

1K5

3237

1K5

33N

2237

+150V

BC858

7225*

2204*

330P

22R

3204*

2217*

330P

22R

3217*

3K3

3219

2K2

3220

270P

2230*

3230*

22R

3233

3K3

2K2

3234

470R

3205*

+8C

BC858

7210*

3K3

3206*

3207

2K2

5235

4K7

3171*

2189*

100NF

TP32

9190

9191

3144*

15K

+8V

3151

22K

+8V

BC848

7170*

1136

1135

9111

9110

2112*

3N9

TP35

3189

+11

100U

2187

2188*

100N

TDA7052A

7187

3185

3K3

3184*

4K7

2191

100U

3191*

68R

4N7

2143*

18K

3170

10N

2170*

3143*

82P

2169*

TP31

3152*

2155

2152

2180

10U

7015/6F

P.16

HEADPHONE

423

9191

9157

2156

2U2

3155*

100K

3156*

100K

7140

10R

3124

7115*

BC858

3112*

1K5

2109

10U

750R

3114*

BC848

7114*

3111*

470R

9112

3115*

6K8

3M3

25R

2M3

10N

2192*

1M3

TP34

TP33

22N

2125*

3126

8K2

27K

3125*

2U2

5101

1137

OFW9453

10K

3119*

3118*

10K

3120*

10K

7126*

BC848B

6115*

BA682

6116*

3121*

4N7

2117*

2101*

4N7

7125

TDA3843

2128

10U

4U7

2126

2U2

2127

10U

2124

6170*

BC848C

7184*

10K

3188*

+8V

3K3

3182*

68K

3181*

330K

3187*

9188

9192

2184*

2N2

2185

330N

9143

9183

RES

9114

3194*

3117*

10K

BC848B

7127*

BC848

7183*

9125

3173*

9156

2217

2206

2204

2202

2192

2191

2189

2188

2187

2185

2184

2180

2170

2169

2156

2155

2152

2143

2128

2127

2126

2125

2124

2117

2112

2109

2101

1990

1137

1136

1135

A B C D E F G H I J K L M

A36

D30

A-C

A40

A39

A38

A37

D23

D24

D26

D27

D28

D29

VG2

AQUA

3L2

2L21L2 4L2

EHTVG2 FOCUS

OFF

CUT

WHITE

AQUADAG

2L1

3L1

1L1

FOCUS

25KV

5 6

FOCUS

VG2

VG1

397

1990

4L1

5L1

P30 DISPLAY

+150

WHITE

CUT

OFF

CUT

OFF

C65 RGB & DISPLAY COMPONENTS

CRT PANEL

E22

E11

WITH HEADPHONE

AM SOUNDSCART AUDIO IN /

AUDIO OUT

FM SCART

SWITCH

I/E AUDIO

VOLUME

ONLY MULTI P/S BGLL'

ONLY

SCART +A/V

- AM DETECTOR -

HEADDPHONE

WITHOUT

SCART AUDIO IN

SONEGROUND

B43 AMPLIFIER

5 6

HEF4053

L/L'

B33 SOUND

FM SCART

AUDIO OUT

FM SCART

I/E AUDIO

SWITCH

- FM DETECTOR -

CVBS

BG/I

A50

A52

C32

C33

A46

A48

A-D-E

IDENT

A12

E12

F11

F20

E20

BG/L

E21

F21

C31

AM SOUND

SCART AUDIO IN/

INT/EXT

C31

C32

C33

A45

OUT

SCART

AUDIO

F19

C59

2230 2237 3111 3112 3114 3115 3117 3118 3119 3120 3121 3124 3125 3126 3143 3144 3151 3152 3155 3156 3170 3171 3173 3181 3182 3184 3185 3187 3188 3189 3191 3194 3202 3203 3204 3205 3206 3207 3208 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3224 3225 3226 3227 3228 3229 3230 3232 3233 3234 3236 3237 3244 5101 5235 6115 6116 6170 6205 6218 6227

7114 7115 7125 7126 7127 7140 7170 7183 7184 7187 7205 7210 7211 7212 7218 7225 7227 9110 9111 9112 9114 9125 9143 9156 9157 9183 9188 9190 9191 9192 9201 9202

K1 L8 L8 I7 C3 I9 J1 K7 J8 H6 H6 J7 J7 J6 L8 L6 L6 H2 L9 L8 L7 L4 L4 K3 K3 M4 K2 K2 A7 C6 E5 D6 E6 E4 I2 J2 J2 J2 J8 I8 I8 I8 J8 H6 I5 J5 L8 L8 K8 L6 H4 H4 L9 L8 L8 I5 I5 L5 L5 H5 H5 K4 K2 L3 B6 B5 B6 B7 B5 B5 B6 C7 D7 D7 B7 D6 C6 C5 D6 C7 D5 D5 D6 D6 E6 E7 E7 E7 E6 E5 E6

E5 E4 E4 E6 I7 E4 I8 J8 L8 B6 C6 E6

J2 I2 I6 I8 J8 I4 L8 I5 I5 K4 B6 B7 C7 D7 D6 E7 E6 I4 J3 J1 K6 J5 L5 H3 H3 L5 H5 L3 L3 I3 D6 B7

Page 25

22 B3 47 J2 47 J4 49 C3 1500 A2 2401 I1 2402 J2 2404 K2 2405 L2 2414 H2 2415 I2 2416 J2 2440 H5 2442 I5 2443 L5 2444 H5 2445 J5 2446 K5 2448 J3 2449 J3 2450 I4 2451 I4 2453 L6 2458 J3 2460 L4 2463 L5 2470 I3 2500 B3 2502 D3 2504 D3 2505 D4 2506 B6 2508 E5 2509 B4 2510 D5 2511 D5 2514 D6 2515 D5 2516 D3 2520 D5 2523 B5 2524 E4 2530 F3 2532 F5 2534 F2 2540 F6 2561 G4 2562 G4 3235 J5 3238 J5 3400 K1 3401 K2 3402 J1 3403 K2 3404 L2 3405 L2 3406 L2 3407 L2 3408 H2 3410 L2 3411 L2 3412 K2 3415 J2 3416 J2 3440 H5 3441 H6 3442 I6 3444 H5 3445 I5 3448 K5 3449 K5 3451 I4 3455 H4 3456 H4 3457 J3 3460 L4 3470 J3 3480 I4 3501 C3 3504 A3 3507 B5 3508 D5

3509 B5 3510 D5 3512 D4 3513 D4 3516 E3 3517 D5 3518 D5 3519 B4 3520 B4 3521 E5 3523 D4 3524 B4 3525 B4 3527 E5 3528 E4 3540 F5 3570 F4 3571 F4 3573 G4 3574 F4 3576 F5 3577 F5 5441 I5 5443 K5 5445 K3 5447 J3 5449 K5 5480 I4 5500 C3 5525 E3 5532 F5 5534 F3 5540 F5 5541 F6 5550 D6 5552 E4 6416 I2 6417 H2 6440 H6 6443 L5 6447 J5 6449 L6 6451 I4 6470 J3 6502 D3 6503 D3 6504 D3 6505 D3 6515 D5 6516 E3 6521 D6 6530 F3 6540 F5 6570 F4 6571 F4 7400 H2 7440 H5 7445 J5 7514 C4 7525 E4 7571 F5 7575 F4 9400 J2 9460 L4 9480 I4 9506 E6 9523 D4 9524 C5 9560 G5 9561 G6 1M1 A3 1M2 C2 1M5 J4 1M6 I3 2M1 A2 2M2 C2 2M6 J5 3M6 J5 4M5 J4 4M6 L4 5M5 K2 6M5 J2

Page 26

B3 1679 C12 24B-24C B5 25B-26 B4 25C-26 B5 2602 G2 2610 G2 2611 H2 2622 G7 2623 H6 2624 H6 2629 H6 2630 H5 2635 C11 2636 C11 2641 F12 2648 C10 2651 F2 2656 H9 2659 G12 2660 C3 2669 B10 2677 E2 2680 C11 2681 C12 2685 C3 2691 D2 2692 G9 3600 C5 3601 H2 3602 H2 3603 G2 3604 G2 3605 G2 3606 F2 3607 F2 3608 F8 3609 G4 3610 G2 3611 H2 3612 H2 3613 H6 3614 F5 3615 H5 3616 F5 3617 H5 3618 G4 3619 F5 3620 F5 3621 F7 3622 F7 3623 G6 3624 G6 3625 F6 3626 G6 3627 G6 3628 F6 3629 G5 3630 F3 3631 F3 3632 G5 3633 H6 3636 B10 3637 B11 3638 H11 3639 F11 3640 G10 3641 G11 3642 G11 3643 F11 3644 G12 3645 F11 3646 D1 3647 G10 3648 C10 3649 F12 3650 C6 3651 F4 3652 F10 3653 F10 3654 G9 3655 G9 3656 H9

3657 C6 3658 G12 3659 G13 3660 C3 3661 C7 3662 C4 3663 C3 3664 B9 3665 B9 3667 C9 3668 B10 3669 B10 3670 C9 3671 C6 3672 B8 3673 B7 3674 B8 3675 C3 3676 C2 3680 H7 3681 C8 3682 F7 3684 G7 3685 G7 3686 H3 3687 H3 3688 H3 3689 H3 3690 C5 3691 F1 3692 F3 3693 G3 3694 C4 3695 C6 3696 C6 3697 C4 3698 G9 3699 C5 6602 G2 6616 H5 6641 H11 6642 H11 6644 H12 6663 B3 6691 E2 7600 D2 7601 F7 7605 F2 7638 G11 7640 G11 7641 G11 7642 G11 7644 G12 7651 G10 7665 C9 7670 C10 7672 B8 7673 B7 7685 H8 7686 G3 7691 E1 9052 B8 9148 B7 9266 B11 9609 H4 9610 F1 9611 A13 9614 G5 9616 F7 9618 A14 9650 H10 9651 F4 9652 G4 9653 A13 9658 G4 9663 C3 9665 B3 9670 C10 9671 C9 9678 F1 9679 C1 9686 G3 9692 F9

Page 27

3678*

+5STBA

+5STB

9610

2690*

100N

3600*

2U2

2630

3615

9616

6K8

3617*

3616*

18K

5640

9679

+5B

9623

9653

9618

9611

18K

3690*

6601*

2V4

3624*

33K

2624

3613*

33K

LL4148

6679*

4K7

3699*

+5A

3696*

100R

3669*

10K

BC848

7670*

330P

2669*

3670*

10K

BC848

7665*

3665*

3664

33K

3667*

10K

TP19

TP18

3668

47K

7651*

BC848

2602

10U

+5B

390R

3687

3686

47K

3693*

3692

470K

3630*

360K

3631

7686*

BC848

100K

3689*

2M2

3688*

2611

220N

2610

220N

10K

3612*

101.5

10K

3601

8K2

3602

HZT33

6602

+5STB

24K

3603*

10K

3611*

15K

3610*

3604*

220K

3605*

PMBT2369

7605*

22K

3607*

10K

3606*

10K

3651*

RES

3618*

100K

2629

2623

3627*

100K

+5STBA

33k

3620*

22K

3625*

18K

3628*

3623*

22K

3626*

100K

+5STBA

3684*

3K3

3685*

3K3

+5STB+5STB

SERVICE

RES

4.0MHZ

1679

9624

+5B

9617

2K7

3655*

3658*

2K7

270P

2658*

TP20

+8C

1N4148

6658

620R

3659*

7658*

PMBT2369

2676*

270P

2678*

10P

2677*

10P

5677 47UH

UHF

6603*

MULTI

6605*

LL4148

6604*

68K

3657*

3661

10K

3681

820P

2695*

2685

100U

2660*

+5STBC

100R

3660*

1685

2 3

2682*

100P

7673*

BC848

3673

+8A

3672

BC848

7672*

820P

2696*

TP17

3662

4K7

3656*

2691*

10K

3676

100R

3698*

820P

2698*

9052

9148

9670

9671

3666*

7685

ST24CO2

+5STB

9650

9652

9658

9686

BC858

7601*

3629*

3633*

3695*

100R

+5A+5C

3663

560R

96639669

3663

560R

96039669

3663*

560R

96039669

9668

9666

RC5

CPU

4MHz

SERVICE

I C

AFC

OSD

3632*

1K8

3679*

+5STB

9665

9667

B4-B4534

6663

3675

2K7

+5STBC

* ONLY NO MENU

7685

9686

9679

9671

9670

9669

9668

9667

9666

9665

9658

9653

9652

9650

9624

9623

9618

9617

9616

9611

9610

9603

9148

9052

7686

7673

7672

3673

3672

3670

3669

3668

3667

3666

3665

3664

3663

3662

3661

3660

3659

3658

3657

3656

3655

3651

3633

3632

3631

3630

3629

3628

3627

3626

3625

3624

3623

3620

3618

3617

3616

3615

3613

3612

3611

3610

3607

3606

3605

3604

3603

3602

3601

3600

2698

2696

2695

2691

2690

2685

2682

2678

2677

2676

2669

2660

2658

2630

2629

2624

2623

2611

2610

2602

1685

1679

MLKJIHGFEDCBA

NO MULTI

---

6603

6605

---

ONLY UHF

LL4148

---

MULTI/I

---

LL4148

SAA5541

C11

VOLUME

INT/EXT

A19

FLYBACK

VERT

HOR

FLYBACK

AFC

SCL

SDA

+5V

IDENT

BSW1

BSW2

OSD-G

L/L'

BG/L

P+

P-

ONLY MUL TI

P/S BGL'I

7600

VVARI

G30 CONTROLS

A-C-D

A10

A12

C12

A14

A13

A17

A16

A18

OSD FAST BLANKING

C20

A20

A21

STANDBY

A25

CONTRAST

BRIGHTNESS

SATURATION

A54

D34

P.O .R

3676 3678 3679 3681 3684 3685 3686 3687 3688 3689 3690 3692 3693 3695

D7 G8 J3 H7 I3 I3 E2 E2 D2 D2 J3 E3 E3 F8

7670

7658

7651

7605

7665

7601

7600

6679

6663

6658

6605

6604

6603

6602

6601

5677

5640

3699

3698

3696 G8

G7 G7 C4 K4 H2 C3 G7 G7 F7 K2 E7 J3 D6 H4 D4 F3 K3 J7 K7

3675 E7

Page 28

1.- SMALL SIGNAL PROCESSING (Diagram A)

The small signal is processed by TDA8361, (TDA8360 no scar t) for Pal sets and TDA8362 for Pal/Secam sets (IC 7015), including IF detection, video processing, chroma decoder, RGB processing, sync processor and FM sound decoder.

1.1- IF detection (IC7015/6A)

- IF input (pins 45,46): The IF signal comes from pin 11 of the tuner to the IF SAW (Surface Acoustic Wave) filter (1015) and the IF-detector IC7015/6A (pins 45 and 46).

- IF filter (1015): The IF bandpass characteristic, determined by the SAW filter, is 33.4 to 38.9 MHz. for BG sets, 33.5 to 39.5 MHz. for PAL I sets and 32.4 to 38.9 MHz. for DK sets.

- IF oscillator (pins 2,3): Carrier frequency, present in coil L5040, is tuned at 38.9 MHz. for BG sets or

39.5 MHz for P al I sets

- AGC v oltage (pin 47): The AGC delayed voltage is applied to pin 1 of the tuner. It should be adjusted for 1mV. antenna signal by means of R3021 (pin 49).

- AFC signal (pin 44): The Automatic Frequency Control is obtained from the reference signal of the IFdetector. C2037 smoothes the AFC voltage.

- Identification (pin 4): The identification output is applied to pin 16 of the µC. This signal is high in case of signal detected.

- Video output (pin 7) : This baseband CVBS signal with 2Vpp of nominal amplitude, also contains the FM intercarrier sound signal. Sound is filtered out by a ceramic trap (1032 or 1033) which frequency can be different depending on the system: 5.5 MHz. for BGLL’, 6.0 MHz. Pal I or 6,5 MHz. for DK.

Multistandard sets

-The IC TDA8362 changes automatically between negative (BGIDK) and positive (LL’) modulation. The IC also determines if the AGC circuit should control at the top white level of the video (positive modulation) or at the top sync level (negative modulation).

-Saw filter (1015) bandpass characteristic is modified by BG/L switching signal proceeding from the microcontroller:

- For BGIDK reception BG/L is low, D6014 does no conduct and the bandpass filter is tuned by 5012 and 2013 at 32.9MHz. to 38,9 MHz.

- For LL’ reception BG/L is high, D6014 conducts and so the bandpass filter is tuned by 5012 and C2014 at 32.4 to 38.9 MHz.

-Oscillator frequency is controlled by the L/L’ switching signal:

-For BGIL reception L/L’ is low, D6042 conduct and so coil 5043 is connected in parallel to 5040.

- The circuit is tuned to 38.9 MHz.

- For L’ reception L/L’ is high, D 6042 does nor conduct and the circuit is tuned to 33.4 MHz. by L 5040 only.

1.2- Source select, luminance and chroma separation (IC7015/6B)

- Source select (pin 13, 15, 16): The internal CVBS signal is now fed to pin 13 IC7015/6B. External CVBS from the pin 20 of Euroconnector is present on pin 15. The source selector switch between internal (pin 16 = 0V.) or external (pin 16 = 8V.).

- Luminance and chrominance separation: Chrominance signal is filtered out (-20dB) by a luminance notch filter which is internally calibrated at the subcarrier frequency (4.43MHz).

1.3- Chroma Decoding (IC7015/6C) Pal or Secam signals are recognized automatically by the IC . For Pal signals decoding is made in IC7015/

6C and for Secam signals in IC7250 (TDA8395).

- Pal signal: This signal is amplified and demodulated. The 4.43 MHz. reference crystal for chrominance demodulation is present at pin 35 of IC7015/6C. The R-Y and B-Y out-puts (pins 30, 31) are applied to chroma delay line IC7221 (TDA4665).

- Secam signal (pin 27): This signal is applied to pin 16 of Secam decoder IC7250.

CIRCUIT DESCRIPTION

Page 29

- Secam reference (pin 32): Pal or Secam signals are recognized using a DC level by bi-directional communication line between this pin and pin 1 of IC7250.

-If IC7015/6C has detected a P al signal, Vpin 32 is made 1,5V. By then the demodulated R-Y and BY outputs (pins 30, 31) are applied to delay line IC7271.

-If IC7015/6C has not detected a Pal signal, Vpin 32 is made 5V. By then the demodulated R-Y and B-Y at outputs (pins 30, 31) are not used.

-If IC7250 has detected a Secam signal, Vpin 1 IC7250 becomes low, sinking typical 150µA. current from pin 32 (5V.) of IC7015/6C, which one detect this current to know that a Secam signal has been detected. In this case R-Y and B-Y signals are applied to the delay line IC7271 via outputs of

IC7250 (pins 9 and 10). This bi-directional communication line uses AC level to calibrate the 4,43MHz. between the PLL and chroma cloche filter of IC7250.

1.4- RGB-dematrixing(IC7015/6D)

- R-Y, B-Y inputs (pins 28, 29): The R-Y and B-Y signals come from delay line (IC7271) and the Y signal comes (internally) from IC7015/6B. The sandcastle pulse coming (internally) from the IC7015/6E (pin 38) synchronizes RGB dematrixing and suppresses the RGB signals during line and frame flyback.

- Video controls (pins 17, 25, 26): These inputs for contrast, brightness and saturation can be adjusted from 0,5V to 4,5V by the µC . If beam current is limited reducing contrast with D6289 circuit.

- RGB inputs (pins 22, 23, 24): External RGB inputs come from Euroconnector and are switched by fast blanking.

- Fast blanking (pin 21): When voltage of pin 21 is 0,4V. internal RGB is used. For a pin 21 voltage between 0,4V. and 3,5V. the set switch to external RGB. If voltage of pin 21 is 4V. both internal and external are deleted. The up uses this status to insert RGB signals from OSD generator directly to RGB outputs. Fast blanking can switch signals for full screen (by a DC voltage) or for a part of the screen (by a pulse voltage).

- RGB outputs (pins 18, 19, 20): See RGB amplifier.

1.5- Horizontal synchro (IC7015/6E)

- Start up (pin 36): When the set is switched on, voltage at pin 36 rises and when exceeds 7V. the horizontal oscillator starts running at approx. 25 KHz. (slow start). After the line starts, main supply of IC7015 (pin 10) comes up to 8V. and the line frequency changes to 15625 Hz.

- Standby (pin 36): This pin is used also for standby function. In this case the voltage is reduced to 3V. by the uP and so the line is shut down.

- Hor. oscillator: This oscillator is fully integrated and internally calibrated. Frequency is obtained derived of chroma oscillator on pin 35 of IC7015/6C.

- Hor. sync separator: This circuit (ful ly integrated) separates hor. pu lses of CVBS proceedin g from 7051/6B.

- Oscillator synchro (pin 40): Oscillator is synchronized with video signal by a first control loop circuit. The

control voltage is present at pin 39.

- Hor. phase control (pin 39): Line fly-back (pin 38) is synchronized with oscillator by a second control loop circuit. The control voltage is present at pin 39. Phase can be adjusted by 3354.

- Hor. output (pin 37): Oscillator is converted in square wave voltage at this pin.

- Sandcastle (pin 38): This pin is used as line fly-back input and also as sandcastle output. Levels of sandcastle pulse are 5,3V for burst detection, 3V. for line blanking and 2V. for frame blanking.

1.6- Vertical synchro (IC7015/6E)

- Ver tical oscillator (pin 42): Frequency is obtained dividing frequency of chroma oscillator on pin 35 IC7015/6C. At pin 42 a sawtooth signal is present. Resistor 3342 is used to correct vertical amplitude with beam current.

- Vert. sync. separator: It separates frame sync. pulses from CVBS and so synchronizes frame oscillator.

- Vert. drive (pin 43): This out-put is used to drive the vertical amplifier (7400)

- Vert. feedback (pin 41): this feedback is proportional to deflection current and is used to correct the vert.

drive signal.

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2.- RGB AMPLIFIERS (diagram B)

- RGB inputs : The RGB signals available at pins 20, 19 and 18 of IC7015/6D are drived by emitter followers

(7210, 7211, 7212), to RGB amplifiers.

- Reference voltage (7225): An internal reference voltage of 2.5V. is produced on the emitter of transistor 7225 to keep the black level stable.

- RGB amplifiers (7205, 7218, 7227): Signal is inverted and drived to the CPT by RGB amplifiers. To improve high frequency amplification there are small capacitors (2204, 2217 and 2230).

- Flash-over protections: Clamping diodes to +8V. (6203, 6216, 6229) and 1K5 series resistors (3203, 3216, 3229) are added for protect the circuit from CPT flash-over.

- White adjustment: The gain of B and G amplifiers can be adjusted by 3213 and 3214.

- Cut-off adjustment: The black level of the CPT can be adjusted by 3207, 3220, 3234 and Vg2.

3.- SOUND CIRCUIT (diagram C)

3.1- FM Sound detection (IC7015/6F)

- FM input (pin 5): FM sound is extracted from baseband video (CVBS) proceeding of IF detector and filtered through 1136 (5.5 MHz. for BG sets, 6.0 Mhz. for Pal I sets, 6.5 Mhz. for DK sets).

- FM demodulation: FM - mono sound demodulation takes place in IC7015/6F. No adjustment is required because demodulation is doing by an automatic PLL (4.2 to 6.8 MHz.).

- De-emph asis (pin 1): Sound frequency characteri stic is defined by de-emphasis capacitor C2112 at pin 1.

- External FM audio out (pin 1): The signal at this pin is amplified by T7114 and T7115 to drive the

euroconnector sound outputs (pins 1,3).

- External FM audio in (pin 6): External audio proceeding of euroconnector (pins 2,6) is applied to this pin. Selection between internal or external is done by pin 16 of IC7015/6B. This output is drived to pin 3 of the final sound amplifier IC7187 (TDA7052 or TDA7056).

Multistandard sets:

-FM demodulation: This function is done in the same way that no multi sets. The only difference consist of a second Pal I 6MHz. filter (1135) in addition to the 5,5MHz. BG filter (1136). 6MHz. filter is switched off for BG reception by transistor 7170 depending on BG/I signal.

-AM demodulation: In Multistandard sets, also AM demodulation for LL’ systems is necessary. AM sound is extracted directly from the tuner instead of from baseband video.

AM Sound detection (IC7125)

- AM input (pins 1,16): AM signal at 32,4MHz. for L system or 39,9MHz. for L’, is removed from IF signal coming from tuner by SA W filter 1137 (double band pass characteristic). Sound is switched by T7126, D6115, TS7127 and D6116 depending on L/L’ signal: For L’ reception (L/L’ is high) IF signal is present at pin 1, and For L reception, IF signal is present at pin 2. The required frequency spectrum is fed to pins 1 and 16 of the AM demodulation IC7125.

- AGC (pin 3,5): C2126 and 2127 are AGC related storage capacitors.

- AM So und output (pin 6): T he demodulated signal at pin 6 of IC7125 is supplied to the source selection switch (pins 1, 5 IC 7140).

AM Sound switching (IC7140)

- External audio out (pin 15): Audio out is selected between AM sound (pin1) or FM sound (pin2) by internal switch depending on BG/L signal (pin 10).

- Audio in (pins 3, 4, 5): Top switch in IC7140 select between internal AM sound (pin 5) and EXT sound from SCART (pin3) by INT/EXT signal (pin 9). The output of this selector (pin 4) is fed to input pin 6 of FM demodulator (IC7015/6F).

- Internal AM audio switching (pin 13): This pin is switched to 8V when the set is in L or L’ system (AM sound). Then, pin 1 of IC7015/6F is 8V. and this IC switches internally its sound input from pin 5 to pin 6, where AM sound is present. (Sound proceeding from pin 4 of IC7140 can be internal AM or external).

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3.2- Sound amplifier (IC7187) Sound amplifier can be TDA7052 for 14" and 17" models or TDA7056 for 20" and 21" models.

Amplified sound is drived to the headphones output and lou dspeakers. If headph ones are connected, loudspeakers are switched off. Volume control on DC level is present at pin 4 for TDA7052 or pin 5 for TDA7056.

4.- POWER SUPPLY (Diagram D)

Mains isolated switched mode power supply (SMPS), controlled by IC7514 (TDA4605) in variable frequency mode.

- Switching behaviour: The switching period is divided in on-time, when energy is extracted from the mains into the primary winding (8-12 of 5525), off-time, when energy in the transformer is supplied to the loads via secondary windings of 5525 and dead when no energy is extracted or supplied.

- Standby mode: Output voltages are present when the set is on stand by, due to standby is done cutting line deflection. On-time is lower and power consumption is very low.

4.1- Primary side

- Degaussing: R3501 is a dual PTC (2 PTC’s in one housing). After switch on set, PTC is cold so lowohmic and so degaussing current is very high. After degaussing, PTC is heated so high-ohmic, so in normal operation degaussing current is very low .

- Rectifier: Mains voltage is filtered by L5500, full wave rectified by diodes D6502-D6503-D6504-D6505 and smoothed by C2505 (300V. DC for 220V A C mains).

4.2- Control circuit (IC7514)

- Start up and supply (pin 6): When the set is switched on, a current via R3507 is applied to pin 6. When C2514 is charged to 15V. the power supply starts and a current from pin 5 to T7525 is drived. T7525 and starts conduction and a voltage across transformer windings is built up. The voltage across winding 4-2 is rectified by diode D6521 and used to supply the IC on pin 6.

- Soft start (pin 7): The capacitor C2523 causes a slow increase of the duration of the output pulse during start up.

- IC output (pin 5): This output drives T7525. R3523 is a fuse resistor to protect IC from short circuits in T7525. D6516 limits the maximum voltage in T7525.

- Start conduction of T7525 (pin 8): A voltage proceeding from winding 4-2 is applied to this pin. The zero crossing detector recognizes the complete discharge of the energy stored in the transformer core, in addition to a dead time depending on C2508. This circuit guarantee that T7525 starts conduction at minimum Vds voltage (see signals 4.5 pag 13).

- Primary current info (pin 2): Current primary winding is simulated by a pin 2 voltage.

- Output voltage info (pin 1): The voltage across winding 4-2 is rectified by diode D6515, divided by

R3527, R3518 and R3508 and applied to pin 1. Internal control voltage (Vcont) inversely propor tional to V pin 1 is generated. Tipical Vpin1 is 400 mV.

- Output regulation (pins 1, 2, 8): IC7514 stabilizes output voltage by controlling T-on and so the frequency and the duty cycle:

Start pulse to T7525 is determined by pin 8 circuit (see signals 4.5 page 13 ). Then a sawtood voltage Vpin 2 is generated at pin 2. Stop pulse to T7525 is produced when Vpin 2 reaches Vcont. Output control is done by the following way:

If output is higher, Vpin 1 is higher, Vcont is lower, T-on and output will be reduced.

If output is lower, output will be increased. Output voltage of supply can be adjusted by R3518. Mains voltage variation is stabilized in the following way:

If mains voltage is higher, slope in the sawtood voltage Vpin 2 is higher, stop point is reached before

and T-on is reduced.

If mains voltage is lower, T-on is increased.

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4.3- Protections

- Overload protection (pin 2): This is produced if T-on is increased till Vpin 2 voltage reaches the foldback point (see signals 4.5). The IC will switch into overload mode (off and on continuously).

- Output voltage protections (pin 6): Limiting values of Vpin 6 voltage (7.25 and 16V.) provide under and overvoltage protections for the circuit.

- Mains overvoltage (pin 3): The voltage at pin 3 IC7515 is a measure for the mains voltage and so the DC voltage across C2505. As soon as the voltage Vpin 3 reaches 6.6V. the supply will stop running.

4.4- Secondary side

- Line supply: The value to adjust the supply is 101,5V. for 14" CPT’S, 102,5V. for 17" CPT’S and 107V. for 20"/21" CPT’S. This supply is also used to obtain the +33V. varicap voltage by D6602.

- Auxiliary supply (+11V.): This supply is used for sound output amplifier, for start up the line circuitry and for the stand by of the microprocessor. +5STB is regulated by T7525 and D6575. A +5V. power on reset signal (POR) is obtained during start up by R3573 till T7571 conducts by D6570.

4.5- Po wer supply signals

V cont

V pin 5 = V GS (7525)

I DS (7525)

V DS (7525)

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5.- DEFLECTION (Diagram E)

5.1- Frame deflection This function is performed by the integrated circuit TDA3653 (7400).

- Frame supply (pins 6, 8, 9): Pin 9 is used to supply the IC except output stage which one is supplied by pin 6. At pin 6 there is a higher voltage during flyback time. This is produced adding the flyback signal present at pin 8 to a +25V. supply by D6416 and C2415. Pin 8 is also used to drive vertical flyback input at pin 37 of the up. (IC 7600)

- V ertical input (pins 1, 3): The input circuit is driven by pin 44 of IC7015/6E. Vertical signal is amplified and inverted.

- Vertical output (pin 5): Vertical output is applied to deflection coil. DC current is suppressed by C2404. A voltage propor tional to current deflection is present in R3411/12 and a feedback of it is sent to pin 42 of IC7015/6 by 3407, so that amplitude can be adjusted by 3410. DC feedback is present in R3406. Linearity is corrected by the network around C2405.

- TRC protection (pin 7): When frame deflection is broken down, the tube is protected blanking all the picture by pin 7 output.

5.2- Line deflection The final line transistor is driven by the transformer 5441, whose primary winding is driven by the transistor

T7440 connected to the line drive output of IC7015/6E. The horizontal deflection stage is carried out in a conventional way, with the deflection transistor (T7445) and line transformer (5545). Beam current info (BCI) is present at C2460. There are the following auxiliary supply voltages obtained from line transformer (5545):

+25V.: To supply frame deflection.. +12V.: To obtain +8V. by IC7016 (diagram A) for small signal, +5V. by T7001 (diagram A) for the tuner

and for the microcontroller.

6.- MICROCONTROLLER/TEXT (Diagram E)

The CTN-BB chassis is designed to accept 2 different microcontrollers: SAA5531 and SAA5541. Both microcontrollers are mounted in the same position (7600), and the associated circuitry is the same. The ROM of the ICs contain an specific program that assures all the functions of the appliance, including a MENU to control the set is (see Instructions Manual). For no TXT sets SAA5541 is used. For TXT sets SAA5531 is used which one also contains a teletext decoder, including the following functions: TXT on/off, reveal, freeze, temporary cancellation, clock, subcode, zoom, index, flof, page +/-, X/26 and 8/ 30 packet decoding (station identification and start-up page).

Following there is an explanation of the different functions of the microcontroller indicating pins number assigned:

- Power supply (pins 31, 39, 44): The IC has several +3,3V power supplies, analog (pin 31), core (pin 39), and periphery ( pin 44 ). All supplies are present during stand by.

- P.O.R. (pin 43): POR (power on reset) is activated when the set is switched on (see 4.4 pag 13 ). If the system shows abnormal behaviour it is important to reset it switching off/on the set. Reset can be produced also connecting pin 43 to +5V. for an instant.

- LED (pin 20): The LED (6663) lights up with a low current when the television set is ON and with a high current when the set is on Standby. While the set is receiving a remote control signal, the led is blinking.

- RC5 (pin 45): The commands transmitted by the remote control handset are received by infrared receiver (1685) and passed to the microcontroller for decoding.

- Control keys (pins 10, 11, 12): When a control key is activated, the correspondent pin is connected to ground .

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- I2C bus (pins 49 and 50): The microcontroller is connected to non-volatile memory IC7685 (EEPROM) via bus I2C. Personal preferences (PP) and channel data are stored in the memory. The system can store 79 channels (with the data on tuning voltage and band) and personal preference.

- Service (pin 7): If this pin is connected to earth when the set is switched on, the unit will go into Service Default Mode (see Repair Facilities in chassis CTN Service Manual).

- Options (pins 14, 21, 52): While start up, the microcontroller checks option pin voltages to know the special features of this chassis. This one is implemented changing the associated components of these pins. Different options (menu, multistandard, etc. ) can be seen on tables of diagram E.

- Multistandard out-puts (pins 46, 47, 48): These signals are only used on multistandard units, for switching the system for decoding sound and video. Signals from pins 46 and 47 are inverted and set at the correct level by transistors 7672 and 7673, respectively. After they are inverted together with the signal from pin 48, they make up the system status lines: BG/I is high for Pal I system, BG/ L is high for L and L’ systems and L/L’ is high for L’ system.

- OSD synchronization (pins 36, 37): In order to synchronize the OSD and the TXT information with the picture signal, the VERT FLYBACK signal (pin 37) and HOR FLYBACK signal (pin 36) are added in inverted form to the integrated circuit. Due to this if the video signal is lost, the TXT keeps synchronism. - Video inputs (pins 23 and 24): These inputs are only used on TXT sets. The teletext information is extracted from the video signal inserted on pins 23 (internal video) and 24 (external video), depending on status of INT/ EXT (pin 8).

- Oscillator (pins 41 and 42): A 12-MHz. oscillator is determined by a 12-MHz. crystal between pins 41 and

42.

- Tuning (pins 1, 9, 16, 51): The unit has a VST (Voltage Synthesized Tuning) system. This system works by tuning to a station on the tuner through a linear variation of the tuning voltage (V-VARI) from 0V. to 33V. applied on pin 2 of the tuner. It is generated on pin 1 of the uP and converted to an adequate level for the tuner using T7605. The AFC signal (Automatic Frequency Control) of IF detector is added to the tuning voltage V-VARI by R3689 and R3688 to compensate for the slow variation of the tuning feature. While searching for the station, pin 51 is set on high, which means that the AFC voltage will not be added to the V-VARI. If an IDENT signal is received on pin 16 while searching for a station, the uP stop searching and checks via input pin 9 if the tuning is correct and whether the AFC signal can be activated again.

- AGC auto tuning (pin 30): This pin is used to limit the AGC voltage in automatic tuning so that noise signals are not memorized.

- Band s witching (pins 15, 17, 18): There are 3 outputs for band switching pin 15 for VHFI, pin 17 for VHFIII and pin 18 for UHF. The uP controls the channel band in the tuner by a voltage of +5V. at the correspondent output.

- Picture and sound adjustments (pins 2, 3, 4, 5, 6): Volume control (pin 2), brightness control (pin 3), colour control (pin 4), contrast control (pin 5), and sharpness control (pin 6). The RC networks are used to convert the modulated pulse output to a DC voltage level. These settings can be pre-programmed in the memory as a personal preference (PP). Mute is controlled internally on the up during automatic station search or when the signal received is interrupted (detected via the IDENT signal on pin 16).

- INT/EXT (pin 8): When this output is 0V. the set is switched to external via transistor (7877). This signal is added to the signal from pin 8 of Euroconnector, so that either of them can be used to switch to external. This line is also used by the microcontroller as an input line, to switch the adequate video input (internal or external) used for decoding TXT.

- Standby (pin 19): When this output is high, the set is switched to stand by. The start-up voltage of the TDA8361A (pin 36) is reduced and the line oscillator stops.

- Fast blanking (pin 35): This pin is used for delete the video picture signal while RGB insertion is produced.

- NIL (Pin 27): This control signal is used (only on TXT sets), to eliminate interlacing for TXT signals. It is

applied to the vertical deflection by switching transistor 7640.

- RGB outputs( pins 32, 33, 34): The RGB outputs are used for On-Screen Display (OSD) and also for TXT (TXT character set is used for both functions). RGB signals are applied trough common base amplifiers (7641, 7642, 7644) to RGB outputs of 7015 (pins 20, 19, 18).

Page 35

A FRONT CABINET GREY A14GR B BACKCOVER GREY B14GR C MAINS KNOB C D KNOB ASSEMBLY D E SENSOR COVER E F OWNERS MANUEL F G MAINS SWITCH E/F/G400 G H MICRO SWITCH E/F/G400 H I MAIN PCB*NON SERVICE PART I14 J CRT PCB J14 2502 CAP CERPL 2N2 1KV (MURATA 202055890282 2504 CAP CERPL 2N2 1KV (MURATA 202055890282 2516 CAP CERPL 2N2 1KV (MURATA 202055890282 2524 CAP CERPL 1N 1KV (MURATA) 202055890337 2534 CAP CERPL 1N 1KV (MURATA) 202055890337 3203 RES 1K5 1/2W (KAMAYA) 212010308152 3216 RES 1K5 1/2W (KAMAYA) 212010308152 3229 RES 1K5 1/2W (KAMAYA) 212010308152 3236 RES 1K5 1/2W (KAMAYA) 212010308152 3237 RES 1K5 1/2W (KAMAYA) 212010308152 2505 CAP ELEC 68U 385V PM20 222205758689 2446 CAP POL BN2 1KV6 PM10 222237682822 3235 RES NFR25 1R 1/3W 230620403108 3001 RES 10R 1/3W NFR25 230620403109 3523 RES 33R 1/3W 230620403339 3470 RES 4R7 1/3W NFR25 230620403478 3448 RES 1R 1/3W NFR25H 230620703108 3449 RES 1R 1/3W NFR25H 230620703108 3189 RES 2R 1/3W NFR25H 230620703208 3457 RESNFR25H 27R 1/2W PM5 230620703279 3516 RES MET FILM 100K 232219473104 3202 RES 12K 2W PR02 232219473123 3215 RES 12K 2W PR02 232219473123 3228 RES 12K 2W PR02 232219473123 3507 RES MET FILM 150K 232219473154 3444 RES FLM PRO3 5K6 3W 232219533562 3504 RES VR37 10M 1/2W PM5 232224213108 3501 RES PTC 18R 270V 2K 232266296626 1540 FUSE 630MAMP 242208610417 1500 FUSE 2AMP 250V 242208610536 1272 XTL 4.43MHZ HC-49/U 242254300859 1033 CER FILTER 6.0MHZ 242254903572 1015 SAW FILTER 242254941481 5500 MAINS FILTER 311110835001 5441 LINE DRIVER TRAFO U10 3 311233830882 5040 COIL 312212050190 42 CON HEADPHONES E700 312212879791 160 EHT CABLE 14" 312807801731 5445 IND LINE TRANS 14/17 312813820411 5525 IND SOPS TRANS 14"/17" 312813835322 6 LOOP AERIAL 313010020482 3 LOUDSPEAKER 26 OHMS 313010060191 6663 LED B4-B4534 ROJO 313010070023 1685 IR RECEIVER TSOP 1736SA1 313010070024 6530 DIODE BYV37 313010070028 7600 IC SAA5541 MICRO PAINT 313010070310

Page 36

2450 CAP POL 470N 250V 5% 313010080055 2506 CAP CER Y2 3N3 250VACPM20 313010080068 2500 CAP MKTX2 470N 275V A.C. 313010080071 1679 CER CRYSTAL 12 MHZ 313010080076 1136 CER FILTER 6.0 MHZ 313010080077 1679 CER RESONATOR 12MHZ 313010080220 2 DEGAUSING COIL 14" 313010821271 5 REMOTE CONTROL NO TEXT 313010821361 23 CRT SOCKET 313010861831 1001 TUNER U 1343AS/1 313914712881 7525 SW MODE TRANS STP2N80F1 823009007670 1 TUBE**NON SERVICE PART*** 823009009280 7514 TDA4605/3 IC POWER REG 932204988682 7685 IC ST24C02CB1 932206745882 7016 IC REGULATOR MC78M08CT 933623810682 6602 DIODE HZT33 933676010673 6447 DIODE BYD33M 933741030133 6516 DIODE BYD33M 933741030133 7445 TRANS BUT11AF 933760560127 7605 TRANS PMBT2369 SMD 933828890215 7187 IC TDA 7052A 935054410112 7400 TDA3653B/N2 IC 935084350112 7271 IC TDA 4665/V4 935193240112 7015 IC TDA8361 E/N5 935200950112

A FRONT CABINET 20" 20/21 B BACK COVER 20" 20 I MAIN PANEL 14" 14 I MAIN PANEL 20" 20 J CRT PANEL 20" 20 1 CRT 14" 823009009280 1 CRT 20" 823020040210 2 DEGAUSING COIL 313010821262 3 LOUDSPEAKER 14" 25OHMS 313010060191 5 REMOTE CONTROL MENU TXT 313010821341 23 CON CRT SOCKET 14"/17" MINI 313010861831 23 CON CRT SOCKET 20/21" NARROW 313010010131 160 EHT CABLE 14" 312807801731 160 EHT CABLE 20" 313010867600 1033 CER TRAP 6,0 MHZ 242254903572 5500 MAINS FILTER 20" 312233831732 6602 DIO HZT33 933676010673 7015 IC TDA8361 E/NS 935200950112 7016 IC MC78M08CT (MOTO) 933623810682 7187 IC TDA 7D66/N2Z 935054420112 7514 IC TDA 4605-2 932204988682 7525 TRA FET STP2N80 FI 823009007670 7600 IC SAA5531 MICRO PAINT TXT 313010070320

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NOTES

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NOTES

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MATSUI 1410R/1410T/2010R