Roadstar sm 142 schematic

R

- SM-142

SM-142

Service Manual

CONTENTS PAGE

Safety Instructions 1 Technical Specifications 2 Instructions Manual 4 Pin Voltages of IC’s 15 Pin Voltages of Some Transistors 18 Oscillograms 19 Electrical and Service Adjustments 21 Trouble Shooting Guide 24 Convergence Adjustments 31 Channel Frequency Tables 33 Part List 37 Circuit Diagrams Attac hed

PIN VOLTAGES OF IC'S

IC101 (TDA956X H)

TV signal processor-Teletext Decoder with embedded u-Controller

Pin Connection V DC (*) Pin Connection V DC (*)

1

Volume +/- 3,2 (3,2)

2

Status 1 0 (0)

3

Status 2 0 (0)

4

Digital ground for u-controller 0 (0)

5

Not connected 0.75 (0.25)

6

Standby on/off 0.01 (3.9)

7

Analog Gnd of text decoder and dig Gnd of TV processor

8

Secam PLL decoupling 2.3 (0)

9

2nd supply voltage TV proc (8V) 8.0 (0.26)

10

Supply volt.deccoup. of dig. Gnd of TV processor

11

Phase 2 filter 2.73 (0)

12

Phase 1 filter 3.9 (0)

13

Gnd 3 for TV processor 0 (0)

14

Decoupling bandgap 4.0 (0)

15

AVL (90 versions) / East/West drive signal (110 versions)

16

V-drive B output 1.0 (0)

17

V-drive A output 1.0 (0)

18

IF-1 input 1.87 (0)

19

IF-2 input 1.87 (0)

20

Reference current input 3.9 (0)

21

Vertical sawtooth capacitor 3.8 (0)

22

Tuner AGC output 4.3 (0)

23

Sound IF input 1 1.9 (0)

24

Gnd 0 (0)

25

Gnd 0 (0)

26

Norrow band PLL filter 2.2 (0)

27

AVL (Automatic Vol. Levelling) 0.42 (0.08)

28

Ext. Audio (audio 2) input 3.73 (0.08)

29

Audio 3 input (not connected) 3.73 (0.09)

30

H-drive output 2.33 (0.26)

31

Sandcastle output-Hor.Fly.input 0.56 (0.25)

32

Decoupling sound demodulator 2.0 (0)

33

QSS intercarrier output / AM output 3.43 (0.3)

34

EHT / overvoltage protection input 2.2 (0.08)

35

IF-PLL loop filter 2.45 (0)

36

Sound IF AGC 0.5 (0)

37

QSS output 0.6 (0)

38

IF video / selected CVBS output 3.0 (0)

39

main supply voltage TV processor 8.0 (0.25)

40

Internal CVBS input 3.8 (0)

3.0 (0.5)

0 (0)

5.0 (0)

41

Gnd for TV processor 0 (0)

42

External CVBS input 0 (0)

43

Gnd for TV processor 0 (0)

44

SVHS-Y input 3.35 (0)

45

SVHS-C input 0 (0)

46

White stretch capacitor 3.4 (0)

47

CVBS output 2.8 (0.07)

48

Audio output/AM audio output 3.45 (0)

49

2nd IF video output (not conn.)

50

2nd RGB / YUV insertion input 0.17 (0)

51

Red input 2.6 (0)

52

Green input 2.6 (0)

53

Blue input 2.6 (0)

54

Beam current limiter input 2.6 -3.4 (0)

55

Black current input / V-guard input 4.6-5.7 (0)

56

Red output see oscilog.

57

Green output see oscilog.

58

Blue output see oscilog.

59

Analog supply of text decoder and dig.supply of TV proc (3.3V)

60

OTP programming voltage 0 (0)

61

Dig. Supply to core (3.3V) 3.3 (3.3)

62

X-tal Gnd 0 (0)

63

X-tal input

64

X-tal output

65

Programming Reset (not connected) 0 (0)

66

Dig. Supply to periphery (3.3V) 3.3 (3.3)

67

SCL1 (Eeprom) 3.3 (3.3)

68

SDA1 (Eeprom) 3.3 (3.3)

69

IR input 3.3 (3.3)

70

Not connected

71

SCL see oscilog.

72

SDA see oscilog.

73

MSP reset (IC301) 4.9 (0)

74

Mute 0 (3.3)

75

SVHS switching 3.3 (3.3)

76

L/L' switching 3.3 (3.3)

77

F Blank MM Not conn. 3.3 (3.3)

78

Program + 3.3 (3.3)

79

CVBS sync filter 3.3 (1.8)

80

Program - 3.3 (3.3)

3.3 (3.3)

(*)

Standby values are given in parenthesis

Note: The function of pin 15, 27, 33 and 48 is dependent on the mode of operation (mono intercarrier mode / QSS IF amplifier and East-West output or not) and is controlled by some software control bits.

IC 301- MULTI STANDARD SOUND PROCESSOR (MSP 3400D)

Pin Connection V DC Pin Connection V DC

1

Not connected

2

Gnd 0

3

Gnd 0

4

Gnd 0

5

Gnd 0

6

Gnd 0

7

Supply 4.9

8

Supply 4.9

9

SCL 2.4-2.6

10

SDA 1.8-2.1

11

Not connected 2.4

12

Not connected 2.4

13

Not connected 2.4

14

Not connected 4.9

15

Not connected 0.7

16

Not connected 0.7

17

Not connected 0.7

18

Supply 4.9

19

Gnd 0

20

Not connected 0.7

21

Gnd 0

22

Gnd 0

23

Gnd 0

24

MSP, RESET 4.9

25

Headphone sound output (R) 2.1

26

Headphone sound output (L) 2.1

27

Gnd 0

28

R-out 0.1-2.1

29

L-out 0.1-2.1

30

Dolby on (C) 0.1-2.1

31

Dolby on (SUB) 0.1-2.1

32

Dolby on (S) 0

33

Scart 2 sound output (R) 3.7

34

Scart 2 sound output (L) 3.7

35

Gnd 0

36

Scart 1 sound output (R) 3.7

37

Scart 1 sound output (L) 3.7

38

Volume capacitor Main

39

Analog Supply 8

40

Volume capacitor Aux

41

Gnd 0

42

Analog ref. supply 3.7

43

Scart 4 input (L) 3.7

44

Scart 4 input (R) 3.7

45

Gnd 0

46

CINCH - sound input (L) 3.7

47

CINCH - sound input (R) 3.7

48

Gnd 0

49

Scart 2 sound input (L) 3.7

50

Scart 2 sound input (R) 3.7

51

Gnd 0

52

Scart 1 input (R) 3.7

53

Scart 1 input (L) 3.7

54

A/D converter ref. Voltage 2.5

55

Mono sound input 3.7

56

Gnd 0

57

Analog Supply 4.9

58

IF input 1 1.5

59

- 1.5

60

IF input 2 0

61

Gnd 0

62

Crystal oss. input 2.3

63

Crystal oss. output 2.3

64

Gnd 0

IC303, IC304 Audio Output IC

Pin Connection V DC Pin Connection V DC

1

Left In 1.6

2

Left In V 1.6

3

Mute 15.3

4

Right In V 1.6

5

Right In 1.6

6

Gnd 0

7 8

Right out 14.2

9

VS 28

10

Left out 13.9

11 12

Left In 0.6

0,5-0,9

IC501 TDA835X

Pin Connection V DC Pin Connection V DC

1

Input A 0,98 (0)

2

Input B 0.94 (0)

3

Supply voltage 14,7 (1.0)

4

Output B 7,55 (0,4)

5

Gnd 0 (0)

6

Vertical Flyback Supply Voltage 45,6 (10,9)

7

Output A 7,64 (0,1)

8

Guard Output 0,3 (0)

9

Feedback Input 7,9 (0)

IC601 MC44608 AP

Pin Connection V DC Pin Connection V DC

1

Demag 0.85 (0.0)

2

I sense 0.1 (0.32)

3

Control input 5 (5.5)

4

Gnd 0

(*)

Standby values are given in parenthesis

5

Driver 2.1 (0.14)

6

VCC 12.3 (8.8)

7

Not connected -

8

VI 116 (117)

IC701 TDA6107

Pin Connection V DC Pin Connection V DC

1

Red in 2.3-2.5

2

Green in 2.5-2.7

3

Blue in 2.5-2.7

4

Gnd 0

5

Black 4.5-5.5

6

Vdd supply 190

7

Red out 134-137

8

Green out 128-130

9

Blue out 130-137

Standby VDC

TV ON VDC

Standby VDC

TV ON VDC

PIN VOLTAGES OF SOME TRANSISTORS

1. PH601 (PC127FY) PHOTOCOUPLER 2. T603 (BC848) NPN Standby VDC

1 B C E B C E 2 3 4

3. T604 (BC848) NPN 4. T605 (BC848) NPN

12.5

11.5

5.5

8.8

Standby VDC TV ON VDC Standby VDC TV ON VDC

B C E B C E B C E B C E

ON VDC

11 10

5

12.3

T603

0.6 0.02 0 0.1 0.3 0

T604

5. T606 (BC848) NPN 6. T607 (BC848) NPN

T606

7. T307 (BC848) NPN

T307

0.02 12.7 0 0.7 0.05 0

Standby VDC TV ON VDC Standby VDC TV ON VDC

B C E B C E B C E B C E

0.6 0 0 1 6.8 0

B C E B C E

0.6 0 0 0.1 15 0

T605

T607

0.6 0.02 0 0.1 0.7 0

0.6 0 0 0.1 2.5 0

Note:

TV is connected to a patern generator (Colour bar, sound 1 kHz).

OSCILLOSGRAPHS OF SOME IC PINS

500 mV/div, 20 usn/div, Vpp=1.2 V, 15625 kHz

500 mV/div, 20 usn/div, Vpp=2.1 V, 15625 kHz

500 mV/div, 20 usn/div, Vpp=2.7 V, 15625 kHz

500 mV/div, 20 usn/div, Vpp=2.6 V, 15625 kHz

500 mV/div, 20 usn/div, Vpp=2.4 V, 15625 kHz

1. IC101 (TDA956X)

Pin 30

2V/div, 20 usn/div, Vpp=4.9 V, 15625 kHz

Pin 38

2V/div, 20 usn/div, Vpp=2.9 V, 15625 kHz

Pin 47

Pin 31

2V/div, 20 usn/div, Vpp=5.6 V, 15625 kHz

Pin 40

Pin 55

Pin 56 Pin 57

Pin 58 Pin 71

2 V/div, 1 msn/div, Vpp=5.2 V

Pin 72

2 V/div, 1 msn/div, Vpp=5.2 V

2. IC301 (MSP34XX)

Pin 28

500 mV/div, 1 msn/div, Vpp=1.8 V

3. IC501 (TDA835X)

Pin 1

500 mV/div, 10 msn/div, Vpp=1.4 V, 50Hz

Pin 7

500 mV/div, 10 msn/div, Vpp=44.6 V, 50Hz

Pin 29

500 mV/div, 1 msn/div, Vpp=1.8 V

Pin 2

500 mV/div, 10 msn/div, Vpp=1.4 V, 50Hz

4. T501 (2SK2381)

Gate (EW drive)

Drain (EW drive)

2 V/div, 10 usn/div, Vpp=10.7 V, 50 Hz