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When servicing note that the reservoir capacitor C809 can remain charged to high voltage for some time after the a.c.

supply is removed. This can result in a shock hazard or damage to components whilst working on the receiver.

Do not try to test Q801 base emitter junction if C809 is charged, your meter will turn on the transistor which will discharge

the capacitor resulting in a collector emitter short circuit. Do not discharge C809 quickly with a screwdriver etc. The very

high current produced can damage the internal connections of the capacitor causing failure at a later date. Remember when

checking voltages to use a return path on the same side of TR802 for the Voltmeter earth to obtain the correct readings.

STANDBY  OPERATION

As mentioned earlier the Start–up Management of MC44608 is as follows:

The Vi pin 8 of IC800 is directly connected to the HV DC rail Vin. This high voltage current source is internally connected

to the VCC pin and thus issued to charge the VCC capacitor. The VCC capacitor charge period corresponds to the

Start–up phase. When the VCC voltage reaches 13V, the high voltage 9mA current source is disabled and the device

starts working. The device enters into the switching phase.

To help increase the application safety against high voltage spike on pin

 

8 a small wattage 1k_series resistor is inserted

between the Vin rail and pin 8. After this start-up the IC can distinguish between the different modes of operation using the

following technique:

MODE  TRANSITION

The LW latch is the memory of the working status at the end of every switching sequence. Two different cases must be

considered for the logic at the termination of the SWITCHING PHASE:

1. No Over Current was observed

2. An Over Current was observed

These two cases correspond to the two signals “NOC” in case of “No Over Current” and “OC” in case of Over Current.

The effective working status at the end of the ON time memorized in LW corresponds to Q=1 for no over current, and Q=0

for over current.

To enter the standby mode secondary side is reconfigured using D889 loop, this starts with the microprocessor ‘s pin

47

 

becomes high; as the standby port becomes high Q503 conducts and Q802 becomes off then  D889 conducts and the

high voltage output value becomes lower than the NORMAL mode regulated value. The shunt regulator IC118 is fully OFF.

In the SMPS stand–by mode all the SMPS outputs are lowered except for the low voltage output that supply the wake–up

circuit located at the isolated side of the power supply. In that mode the secondary regulation is performed by the Zener

diode (D801) connected in parallel to the TL431. The secondary reconfiguration status can be detected on the SMPS

primary side by measuring the voltage level at pin4 of TR802.

In the SMPS stand–by mode the 3 distinct phases are:

The SWITCHING PHASE: Similar to the Overload mode. The current sense clamping level is reduced. When VCC

crosses the current sense section, the C.S. clamping level depends on the power to be delivered to the load during the

SMPS stand–by mode. Every switching sequence ON/OFF is terminated by an OC as long as the secondary Zener diode

voltage has not been reached. When the Zener voltage is reached the ON cycle is terminated by a true PWM action.

The proper SWITCHING PHASE termination must correspond to a NOC condition. The LW latch stores this NOC status.

The LATCHED OFF PHASE: The MODE latch is set.

The START–UP PHASE is similar to the Overload Mode. The MODE latch remains in its set status (Q=1).

The SWITCHING PHASE: The Stand–by signal is validated and the 200uA is sourced out of the Current Sense pin 2.

SMPS SWITCH OFF

When the mains is switched OFF, so long as the electrolytic bulk capacitor provides energy to the SMPS the controller

remains in the switching phase. Then the peak current reaches its maximum peak value, the switching frequency

decreases and all the secondary voltages are reduced. The VCC voltage is also reduced. When VCC is less than 6,5V,

the SMPS stops working.

MICROPROCESSOR  IC501

IC 501 controls all the functions of the receiver operated by the remote control and the front panel customer controls.

It produces the on screen graphics, operates tuning, customers controls and engineering controls, and also incorporates

all of the Teletext functions. It also controls the video processor, the audio processor, and the tuner. The circuits just

mentioned are controlled via the I²C bus. Also IC501 controls the video source switching, vertical position adjustment and

the vertical linearity adjustment via its ports.

An external 8K EEprom is used by the micro. The EEprom comes fully programmed. The main clock oscillator is 4.0MHz

crystal X501 on pins 50 and 51. Reset is provided on pin 2 via Q504. On switching on pin 2 becomes high and the controller

gets reset which stays valid till a low signal comes on that pin.

CONTROLS

Command information from the infra red remote controller is fed through the sensor IC502 to pin 1 of the microprocessor.

Operation of the customer front panel keys is detected by pin 8 that is an ADC (analogue to digital converter). Pressing a

switch will connect the 5V to the ground through a particular resistor that determines the value of the voltage on pin8 at that

instant. This obtained value is comprehended by the micro and the corresponding operation is performed. Refer to the

following table:

Summary of Contents for CG2026S

Page 1: ...nweise zurProduktsicherheit indiesemWartungshandbuchzulesen SERVICE MANUAL MANUEL D ENTRETIEN WARTUNGSHANDBUCH SPECIFICATIONSAND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT Colour Television June 2002 No 0110 C2126S CG2026S C2143S C2144S CG2143S C21F60S C21F65 CL2026S CL2143S CL21F60S CL21F65 Data contained within this Service manual is subject to alteration for improvement Les données fournies da...

Page 2: ...S CMOS 8K EEPROM 24C08 6 11 CLASS AB STEREO HEADPHONE DRIVER TDA1308 6 12 SAW FILTERS 6 13 IC DESCRIPTIONS AND INTERNAL BLOCK DIAGRAM 6 ST92195 7 STV224X 8 9 UV1315 UV1316 UV1336 9 TDA7266 TDA7266L 9 10 TDA8174AW 10 STV5112 11 MC44608 11 12 MSP34X0G 12 24C08 12 13 TDA1308 13 SAW FILTERS 13 CIRCUIT DESCRIPTION 14 18 CHASSIS MANUAL ADJUSTMENT PROCEDURE 19 21 OPTIONAL SETTINGS 22 23 TUNER SETTING 24 ...

Page 3: ...ly 220VAC 50Hz PERI TV SOCKET SCART 1 SC050 SCART 2 SC051 1 Audio right output 0 5Vrms 1K 1 Audio right output 0 5Vrms 1K 2 Audio right input 0 5Vrms 10K 2 Audio right input 0 5Vrms 10K 3 Audio left output 0 5Vrms 1K 3 Audio left output 0 5Vrms 1K 4 GroundAF 4 GroundAF 5 Ground Blue 5 Ground Blue 6 Audio left input 0 5Vrms 10K 6 Audio left input 0 5Vrms 10K 7 Blue input 0 7Vpp 75ohm 7 Blue input 0...

Page 4: ... This is realized by means of a software loop that alternate the demodulator to various frequencies then select the frequency on which a lock condition has been found De emphasis output signal amplitude is independent of the TV standard and has the same value for a frequency deviation of 25kHz at the 4 5MHz standard and for a deviation of 50kHz for the other standards When the IF circuit is switch...

Page 5: ... aligned via a master filter phase locked loop 2 7 RGB output circuit The video processor performs the R G B processing There are three sources 1 Y U V inputs coming from luma part Y output and chroma decoder outputs R Y B Y outputs 2 External R G B inputs from SCART converted internally in Y U V with also the possibility to input YUV signals from a DVD player YUV specification is Y 0 7 V PP U 0 7...

Page 6: ... MHz 2 Enough margin is available to tune up to 863 25 MHz Noise Typ Max Gain Min Typ Max Low band 6dB 9dB All Channels 38dB 44dB 50dB Mid band 6dB 10dB Gain Taper 8dB High band 6dB 11dB off air channels 4 DIGITAL TV SOUND PROCESSOR MSP34X0 The MSP 34x0D is designed to perform demodulation of FM or AM Mono TV sound Alternatively two carrier FM systems according to the German or Korean terrestrial ...

Page 7: ...sive components are used for the solution of power factor correction 10 SERIAL ACCESS CMOS 8K EEPROM 24C08 The 24C08 is a 8Kbit electrically erasable programmable memory EEPROM organized as 4 blocks of 256 08 bits The memory is compatible with the I C standard two wire serial interface which uses a bi directional data bus and serial clock 11 CLASS AB STEREO HEADPHONE DRIVER TDA1308 The TDA1308 is ...

Page 8: ...upt controller The Core has independent memory and register buses to add to the efficiency of the code A set of on chip peripherals form a complete sys tem for TV set and VCR applications Voltage Synthesis VPS WSS Slicer Teletext Slicer Teletext Display RAM OSD Additional peripherals include a watchdog timer a serial peripheral interface SPI a 16 bit timer and anA D converter 785 6 5 37 21 12 7 7 ...

Page 9: ...to meet a wide range of applications It is a combined VHF UHF tuner suitable for CCIR systems B G H L L I and I Features of UV1315 Member of the UV1300 family small sized UHF VHF tuners Systems CCIR B G H L L I and I OIRT D K Voltage synthesized tuning VST Off air channels S cable channels and Hyper band Standardized mechanical dimensions and pinning PINNING PIN VALUE 1 Gain control voltage AGC 4 ...

Page 10: ...t 1 11 Symmetrical IF output 2 General description of UV1336 UV1336 series is developed for reception of channels broadcast in accordance with the M N standard Features of UV1336 Global standard pinning Integrated Mixer Oscillator PLL function Conforms to CISPR 13 FCC and DOC Canada regulations Low power consumption Both Phono connector and F connector are available PINNING PIN VALUE 1 Gain contro...

Page 11: ...T BY 8 PW GND 9 S GND 10 N C 11 N C 12 IN2 13 VCC 14 OUT2 15 OUT2 TDA8174AW INDEPENDENTVERTICALAMPLITUDEADJUSTMENT BUFFER STAGE POWERAMPLIFIER FLYBACKGENERATOR THERMALPROTECTION INTERNALREFERENCE VOLTAGE DECOUPLING General Description TDA8174Aand TDA8174AWare a monolithic integrated circuits It is a full performance and very efficient vertical deflection circuit intended for direct drive of a TV p...

Page 12: ...ff line converters This high voltage circuit that integrates the start up current source and the oscillator capacitor requires few external components while offering a high flexibility and reliability The device also features a very high efficiency stand by management consisting of an effective Pulsed Mode operation This technique enables the reduction of the stand by power consumption to approxim...

Page 13: ...10G FM demodulation of all terrestrial standards incl identification decoding FM demodulation of all satellite standards No external filter hardware is required Only one crystal clock 18 432MHz is necessary FM carrier level calculation for automatic search algorithms and carrier mute function DSP Section Audio Base band Processing Flexible selection of audio sources to be processed Two digital inp...

Page 14: ...nge Excellent power supply ripple rejection Low power consumption Short circuit resistant High performance high signal to noise ratio low distortion PINNING PIN VALUE 1 OutputA Voltage swing Min 0 75V Max 4 25V 2 Inverting inputA Vo clip Min 1400mVrms 3 Non inverting inputA 2 5V 4 Ground 0V 5 Non inverting input B 2 5V 6 Inverting input B Vo clip Min 1400mVrms 7 Output B Voltage swing Min 0 75V Ma...

Page 15: ...rrored and compared to the reference current Iovp 120mA Thus this OVP is quicker than normal number one as it directly sense the change in current rather than waiting for a specific voltage value and is called QOVP In both cases once an OVP condition is detected the output is latched off until a new circuit START UP 3 A software controlled function acts on pin 52 of IC501 This pin monitors feedbac...

Page 16: ...ner diode D801 connected in parallel to the TL431 The secondary reconfiguration status can be detected on the SMPS primary side by measuring the voltage level at pin4 of TR802 In the SMPS stand by mode the 3 distinct phases are The SWITCHING PHASE Similar to the Overload mode The current sense clamping level is reduced When VCC crosses the current sense section the C S clamping level depends on th...

Page 17: ...he frequency changes and not the voltage In frequency tuning the micro generates I C signals to account for a 1Mhz frequency increment on the tuner and then scan all the frequency either manually or automatically This method is faster than the VST and more precise than PLL tunings Automatic fine tuning AFT correction voltage is done internally inside IC403 and fed to the microprocessor via I C BUS...

Page 18: ... G B passes via connector PL405 to the CRT base PCB Here the R G B signal is amplified by IC901 to provide drive for the cathodes of the CRT IC901 produces a feedback signal which is fed to IC403 pin 33 for blanking and auto grayscale correction SOUND PATH The demodulated mono sound is taken from pin 55 of IC403 directly to the sound output stage IC401 Pin 7 The output signal from IC401 is Volume ...

Page 19: ...king The ver_sync signal is output from the pin47 and fed to Pin 41 of IC501 The H_sync pulse is taken from pin 1 of the FBT and fed to the micro at pin 40 These two signals are required by the micro for graphics timing and also for text IC403 generates a vertical pulse signal VER_OUT and V_AMP that are fed to IC600 the vertical stage IC IC600 is supplied by a 26V DC via diode D610 It generates it...

Page 20: ...djust for BLUE 40 BR Bias for RED 31 BG Bias for GREEN 31 APR APR Threshold 10 FMP1 FM Prescaler when AVL is OFF 9 STEREO ONLY NIP1 NICAM Prescaler when AVL is OFF 20 STEREO ONLY SCP1 SCART Prescaler when AVL is OFF 14 STEREO ONLY FMP2 FM Prescaler when AVL is ON 18 STEREO ONLY NIP2 NICAM Prescaler when AVL is ON 39 STEREO ONLY SCP2 SCART Prescaler when AVL is ON 14 STEREO ONLY F1H High Byte of cr...

Page 21: ...to a PAL colour bar pattern with frequency 38 9MHz Apply this IF signal to PIN 10 and PIN 11 of tuner Press PROG 1 and after that BLUE INSTALL button from remote controller Select the standart as BG or I if BG is not available Enter service menu Select IF1 parameter from service menu and press BLUE INSTALL button from remote controller IF adjustment will be done automatically by software See the I...

Page 22: ...comes improper after some other geometric adjustments are done Enter a NTSC M circle test pattern via RF or video inputs Change Vertical Size till the checkered parts of test pattern on both of upper and lower side disappear Check and readjust Vertical Size item if the adjustment becomes improper after some other geometric adjustments are done Enter a NTSC M circle test pattern via RF or video inp...

Page 23: ...e bit numbers 23 9LGHR 2SWLRQV 127 7 WDO RQILJXUDWLRQ 7 WDO 3 WDO 3 176 WDO 3 6 176 WDO 3 6 176 7 QDEOH OXH EDFN ZKHQ QR VLJQDO LQ 9 PRGH GHIDXOW YDOXH EODQN EDFN ZKHQ QR VLJQDO LQ 9 PRGH 7 KLWH QVHUWLRQ LV 21 GHIDXOW YDOXH KLWH QVHUWLRQ LV 2 7 OXH DFNJURXQG ZKHQ QR VLJQDO LQ 79 PRGH LVDEOH OXH DFNJURXQG LQ 79 PRGH 7 6HPL WUDQVSDUHQW EDFNJURXQG IRU 26 GHIDXOW YDOXH 6ROLG 0HQX EDFNJURXQG IRU 26 7 O...

Page 24: ... WXQHU 7 EDQG WXQLQJ 9 9 8 GHIDXOW YDOXH EDQG WXQLQJ RQO 8 7 WUD PVHF EODQNLQJ IRU 967 GHIDXOW YDOXH QR H WUD EODQNLQJ 7 7HOHWH W 2SWLRQV 127 7 127 86 GHIDXOW YDOXH 7 5 6 59 PXVW EH GHIDXOW YDOXH 7 7HOHWH W DQJXDJH URXSV 7 URXS HVW 7 URXS HVW DVW URXS HVW 7XUNLVK URXS DVW ULOOLF URXS UDELF 7 HYLFH W SH VHOHFWLRQ GHIDXOW YDOXH 7 3520 0 7 520 3 520 66 3 3520 0 5 520 0 5 26 3520 0 5 520 0 3 5HDG XWR ...

Page 25: ... RI 9 8 FURVV RYHU IUHTXHQF 6 DQG VZLWFKLQJ E WH IRU 9 6 DQG VZLWFKLQJ E WH IRU 9 6 DQG VZLWFKLQJ E WH IRU 8 RQWURO E WH 127 Q FDVH RI DQ 3520 GHIHFW RX GR QRW QHHG DQ RULJLQDO 0 67 5 3520 WR UXQ WKH 79 DJDLQ HFDXVH the FKDVVLV ZRUNV ZLWK DQ XQSURJUDPPHG 3520 YHQ ZLWKRXW DQ 3520 Q VXFK NLQG RI FDVH VHUYLFH VWDII KDV WKH VDPH W SH RQ WKH FKDVVLV DQG DGMXVW DOO WKH RSWLRQV DFFRUGLQJ WR 0 18 8670 17 ...

Page 26: ...Block Flow Chart 25 ...

Page 27: ...Power Supply 26 ...

Page 28: ...Micro Controller 27 ...

Page 29: ...Video Circuit 28 ...

Page 30: ...Stereo Circuit 29 ...

Page 31: ...Audio Video Connector 30 ...

Page 32: ...Deflection Circuit 31 ...

Page 33: ...CRT Circuit 32 ...

Page 34: ...C21F65 CRT Board ...

Page 35: ...HITACHI No 0110 Video Controller 33 ...

Page 36: ...HITACHI No 0110 SMPS Circuit 34 ...

Page 37: ...HITACHI No 0110 Micro Controller 35 ...

Page 38: ...HITACHI No 0110 Audio Video Circuit 36 ...

Page 39: ...HITACHI No 0110 Deflection Circuit 37 ...

Page 40: ...HITACHI No 0110 Stereo Circuit 38 ...

Page 41: ...14 13 11 9 6 8 7 3 4 2 5 1 39 ...

Page 42: ...47 Milano Italia ITALY Tel 39 02 487861 Tel 39 02 38073415 Servizio Clienti Fax 39 02 48786381 2 Email customerservice italy hitachi eu com HITACHI Europe AB Box 77 S 164 94 Kista SWEDEN Tel 46 0 8 562 711 00 Fax 46 0 8 562 711 13 Email csgswe hitachi eu com HITACHI EUROPE S A S Lyon Office B P 45 69671 BRON CEDEX FRANCE Tel 04 72 14 29 70 Fax 04 72 14 29 99 Email france consommateur hitachi eu co...

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