GRUNDIG STR 7100 FR sat Service Manual

COLOR TELEVISION

SERVICE MANUAL

21” T2S10 CHASSIS WITH NICAM&TELETEXT

CONTENTS

ⅠSAFETY PRECAUTION ………………………………………………… 1 ⅡSPECIFICATION ………………………………………………………… 2 Ⅲ IC’S GENERAL DESCRIPTION ……………………………………… 3 Ⅳ SPECIAL IC INTRODUCTION ………………………………………… 3 Ⅴ CHASSIS BLOCK DIAGRAM ………………………………………… 12 Ⅵ SERVICE MODE&ADJUSTMENT …………………………………… 13 Ⅶ TEST POINT WAVE FORM&SCHEMATIC DIAGRAM …………… 18

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ⅠSAFETY PRECAUTION

1. X-RAY RADIATION PRECAUTION

1.1 Excessive high voltage can produce potentially hazardous X-RAY RADIATION. To avoid such hazards the high voltage must be specified limit. The normal value of the high voltage of this receiver is 21” 25KV ±500V under 230V AC power source. The high voltage must not exceed 26KV for 21” TV

1.2 Each time a receiver requires servicing the high voltage should be checked following the HIGH

VOLTAGE CHECK procedure in this manual. It is recommended the reading of the high voltage be

recorded as a part of the service record. It is important to use an accurate and reliable high voltage meter.

1.3 The primary source of X -RAY RADIATION in this TV receiver is the picture tube. For continued X-RAY

RADIATION protection, the replacement tube must be exactly the same type tube as used in this TV receiver.

1.4 Some parts in this receiver have special safety-related characteristics for X-RAY RADIATION protection.

For continued safety, parts replacement should be undertaken only after referring the PRODUCT SAFETY

NOTICE below.

2. GENERAL SAFETY PRECAUTION

The following are the necessary precautions to be observed before servicing this chassis

WARNING: Service should not be attempted by anyone unfamiliar with the necessary

2.1 Since the power supply circuit of this receiver is directly connected to the AC power line. An isolation

transformer should be used during any dynamic service to avoid possible shock hazard.

2.2 Always discharge the picture tube anode to the CRT conductive coating before handling the picture

tube. The picture tube is highly evacuated and if broken, glass fragments will be violently expelled. Use

shatterproof goggles and keep picture tube away from the unprotected body while handling.

2.3 When replacing a chassis in the cabinet, always be certain that all the protective devices are put back

in place, such as: nonmetallic control; knobs, insulating covers, shields, isolation resistor-capacitor,

network, etc.

2.4 Connection wires must be kept away from components with high voltage or high temperature.

2.5 When replacing parts or circuit boards, disconnect the power cord.

2.6 When replacing a high voltage resistor (metal oxide resistor) on circuit board, keep the resistor APP.

10mm (1/2 in.) away from circuit board.

2.7 If any fuse in this TV receiver is broken, replace it with the FUSE specified in the chassis parts list.

2.8 The receiver is designed to operate with 230V (50Hz) AC mains.

3. PRODUCT SAFETY NOTICE

Many electrical and mechanical parts in this chassis have special safety-related characteristics are often

passed unnoticed by a visual inspection and the X-RAY RADIATON protection afforded by them cannot

necessarily be obtained by using replacement components rated for higher voltage. The use of substitute

replacement parts that do not have the same safety characteristics as specified in the parts list may create

shock, fire, X-RAY RADIATION or other hazards.

Warning!

There are no any repairable components in this TV set. Do not try to make any change to it. High voltage

inside may cause danger.

ⅡSPECIFICATION

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RF SYSTEM

VIDEO SYSTEM PAL SECAM NTSC4.43

TUNING SYSTEM VOLTAGE SYNTHESIZER TUNING

RECEIVING CHANNEL

PROGRAM PRESET 99

AV JACKS

TELETEXT 1PAGE

ANTENNA INPUT

AUDIO OUTPUT

MAIN POWER 170-260V AC 50/60Hz

POWER CONSUMPTION 21” 90W

SOUND SYSTEM:B/G D/K I NICAM STEREO

VHF-L: E2～S6 48.25 MHz～140.25MHz

VHF-H: S7～S36 147.25 MHz～423.25MHz

COLOR SYSTEM: PAL SECAM

UHF: S37～DS57 431.25 MHz～863.25MHz

1 FULL SCART AND 1 AV SCART

75Ω（UNBALANCE）

ⅢCHIP GENERAL DESCRIPTION

1 SIDE RCA AV IN

≥5W

1. MAIN BOARD PART

IC101 ST92195 MCU With ON SCREEN DISPLAY and TELETEXT Decoder

IC102 24C08 8 Kbit Serial I2C Bus EEPROM

IC201 STV2246 I²C BUS-Controlled Multistandard Single Chip TV Processor

IC301 TDA8174A VERTICAL DEFLECTION W.E/W CORRECTION CIRCUIT

IC601 H11A817C OPTOCOUPLERS

IC603 MC7808CT +8V VOLTAGE REGULATOR

IC605

IC602

IC701 CD7522CS 7W AUDIO AMPLIFIER

IC801 STV8216 Multi-standard TV Audio Processor and Digital Sound Demodulator

MC7805CT +5V VOLTAGE REGULATOR

ⅣCHIP INTRODUCTION

1. ST92195

The ST92195 microcontrollers are developed and manufactured by STMicroelectronics using a proprietary

n-well HCMOS process. Their performance derives from the use of flexible 256-register programming model

for ultra-fast context switching and real-time event response. The intelligent on-chip peripherals offload the

ST9 core from I/O and data management processing tasks allowing critical application tasks to get the

maximum use of core resources. TheST92195 MCU support low power consumption and low voltage

operation for power-efficient and low-cost embedded systems.

1.1 Main features

28 fully-programmable I/Os

4 channels Analog/Digital Converter

Built in I

Built in OSD and Teletext decoder

14-bit Voltage Synthesis PWM output for VS tuning system

C bus interface

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1.2 Pin description

Pin No. Pin Name Signal Name I / O Function

1 P2.0 IRIN I IR Input 2 RESET RESET I Hardware Reset 3 P0.7 NC I/O Not Used 4 P0.6 MUTE O Mute Output PIN 5 P0.5 NC I/O Not Used 6 P0.4 ON/OFF O Standby Output 7 P0.3 DESIGN I Service menu control 8 P0.2 SCART1 I Identify scart entering Design

9 P0.1 SCART2 I Identify scart entering Design 10 P0.0 AV SEL O AV Selection 11 P3.7 S0 O AV/TV 12 P3.6 S1 O AV/TV 13 P3.5 TV/DVD O TV/DVD 14 P3.4 DFD O Default data control 15 B B O OSD Blue colour Signal Output 16 G G O OSD Green colour Signal Output 17 R R O OSD Red colour Signal Output 18 BLANK BLANK O OSD Blanking Output 19 P5.1 SDA I/O I2C data line 20 P5.0 SCL O I2C clock line 21 VDD VDD 22 JTDO JTDO 23 WSCF WSCF 24 WSCR WSCR 25 AVDD3 AVDD3 26 TEST0 TEST0 27 MCFM MCFM 28 JTCK JTCK 29 TXCF TXCF 30 CVBSO CVBSO 31 AVDD2 AVDD2 32 JTMS JTMS 33 CVBS2 CVBS2 I CVBS In for VPS / WSS 34 CVBS1 CVBS1 I CVBS In for Teletext Slicer 35 AGND AGND 36 GND GND 37 JTRST0 JTRST0 38 PXFM PXFM 39 AVDD1 AVDD1 40 HSYNC HSYNC I Horizontal Sync Input

Analog Pin For VPS / WPP slicer line PLL Analog Pin For VPS / WPP slicer line PLL

Analog Pin for display pixel freq. multiplier

Analog pin for VPS /WSS line PLL

Analog Pin for display pixel freq. multiplier

+5 V Digital Supply

Test Pin

+5V Analog VDD For PLL

Test Pin

Analog Power supply

Test Pin

Analog ground

Digital ground

Test Pin

Analog Power Supply

41 VSYNC VSYNC I Vertical Sync Input 42 P4.0 BSW1 O Band switch 1

43 P4.1 BSW2 O Band switch 2 44 P4.2 SAW_SW1 O SAW Filter switch 1

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45 P4.3 NC I/O Not connected 46 P4.4 SAW_SW2 O SAW Filter switch 2 47 P4.5 NC I/O Not connected 48 P4.6 Vlin PWM O V-linearity PWM output 49 P4.7 VOL PWM O VOL PWM output 50 XTAL XTAL 51 XTAL XTAL 52 P2.5 LED2 O LED driver 53 P2.4 LED1 O LED driver 54 P2.3 VS O VST Voltage ouput 55 P2.2 NC I/O Not connected 56 P2.1 KB INPUT I KEY Input

1.3 Block diagram

Clock oscillator Clock oscillator

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1.4 General application description

BAND SWITCH OUTPUT (Pin42 Pin43)

Pin42 BSW1 Pin43 BSW2 SELECTED BAND

0 0 NOT USED

0 1 VHF-L

1 0 VHF-H

1 1 UHF

KEYBOARD INPUT LEVEL (Pin56)

KEY IN (Pin 56) KEY PRESSED

0.285 ~ 0.587V Volume – (1 K ohm)

0.706 ~ 1.098V Volume + (2.2 K ohm)

1.204~ 1.596V Program- (3.9 K ohm)

1.704 ~ 2.096V Program+ (6.2 K ohm)

2.194 ~ 2.586V MENU (9.1 Kohm)

2.704 ~ 3.096V TV/DVD (13.8 Kohm)

3.205 ~ 3.606V AV/TV(22 Kohm)

3.745 ~ 4.145V Analog (37.4 Kohm)

4.282 ~ 4.682V OK (86.5 K ohm)

Note:The pull up resistor of Pin56 is 10K.

TV/AV SELECTION (Pin11/Pin12)

S0-Pin11 0 1 0 1

S1-Pin12 0 0 1 1

TV/AV MODE TV AV1/RGB AV2 S-VHS

STANDBY OUTPUT (Pin6)

STD-BY (Pin 6) Mode

0 Standby

1 Operating

2. STV2246H

The STV224XH is fully bus-controlled IC for TV that include PIF, SIF, Luma, Chroma and Deflection

processing functions. Used with a vertical frame booster (TDA8174A for a 90° chassis, STV9306 for a 110°

chassis), they allow multi-standard (BG/DK/I/MN/LL’, PAL/SECAM/NTSC) sets to be designed with very few

external components and no manual adjustments.

2.1 Main features

I²C Bus Control

PIF Circuit with PLL Demodulation (Positive and Negative Video)

SIF Circuit with QSS Structure, FM Demodulation and AM Demodulation for France

Intercarrier Capability and Built-in Sound Band pass

Sound Subcarrier Output for Stereo Chassis (FM, NICAM)

Integrated Chroma Filters and Luma Delay Line and Integrated Chroma Delay Line

3 channels input Video Switch and 2 channels CVBS output

OSD RGB Inputs and external RGB Inputs Interface

PAL/SECAM/NTSC Chroma Demodulators

Black Stretch and peaking Circuit

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Automatic Cut-off Current Loop, manual Cut-off possible for low-cost applications

Two Horizontal Deflection PLLs

APR (Automatic RGB Peak Regulation) or RGB Peak Limitation Function

2.2 Pin description

PIN NO. SYMBOL DESCRIPTION

1 SIFIN1 SIF input

2 SIFIN2 SIF input

3 AGCSIFCAP AGC SIF capacitor

4 V

REFIF

5 AGCPIFCAP AGC PIF capacitor

6 PIFIN1 PIF input

7 PININ2 PIF input

8 TUNERAGCOUT AGC Tuner output

9 IFPLL IF PLL filter

10 GND

11 AM/FMOUT/SC AM/FM Mono sound or stereo carriers output

12 VCC

13 INTCVBSOUT Internal CVBS output

14 EXTAUDIOIN External audio input

15 PIFLC1 LC input

16 PIFLC2 LC input

17 V

CC2

18 CVBSIN1 Internal video input

19 GND2 Video/LUMA ground

20 CVBSIN2 External video input

21 BS Black stretch capacitor

22 Y/CVBSIN3 Y(SVHS) or CVBS3 external input

23 CHR Chroma(SVHS) input

24 APR Automatic RGB peak regulation

25 BEXT/Cb External blue input or Cb input

26 GEXT/Y External green input or Y input

27 REXT/Cr External red input or Cr input

28 FBEXT External fast blanking input

29 NC/CVBSOUT1 Not connected or CVBS output1

30 BOUT Blue output

31 GOUT Green output

32 ROUT Red output

33 I

CATH

34 BOSD OSD Blue input

35 GOSD OSD Green input

36 ROSD OSD Red input

37 FBOSD/HC OSD Fast blanking input/half contrast

38 XTAL3/BTUN 3.5x MHz Crystal or bell filter tuning capacitor

39 XTAL2 3.5x MHz Crystal

40 XTAL1 4.43/3.5x MHz Crystal

Voltage reference filter

IF Ground

5V IF Supply

Video/LUMA Supply voltage (8V)

Cathode current measurement input

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41 CLPF Chroma PLL filter

42 X1/VAMP/CHROUT

43 GND1 Chroma/scanning ground

44 CVBSOUT2 Second video switch output

45 V

46 BCL/SAF Beam current limiter control voltage and safety input(X-ray)

47 VERT Vertical output pulse

48 HOUT Horizontal output pulse

49 LFB/SSC Line flyback input and super-sandcastle output

50 SLPF Scanning PLL filter

51 SCL I2C Bus clock input

52 SDA I2C Bus data input

53 V

54 GNDD Digital ground

55 AUDIOOUT Main audio output

56 FMCAP FM demodulation capacitor

CC1

CCD

2.3 Block diagram

XTAL1 control pin, vertical amplitude DAC output and chroma

reference signal output

Chroma/scanning power supply (8V)

Digital supply voltage(5V)

3. TDA8174A

The TDA8174A are a monolithic integrated circuits It is a full performance and very efficient vertical deflection

circuit intended for direct drive of a TV picture tube in Color and B & W television as well as in Monitor and

Data displays

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