Panasonic Z-421V, Technical Manual

3DQDVRQLF

2

Contents

1

CIRCUIT DESCRIPTION ........................................................................................................................... 3

1.1

S

MALL SIGNAL PART

................................................................................................................................. 3

1.1.1

Tuner and IF output Tuner: ............................................................................................................. 3

1.1.2

Vision IF .......................................................................................................................................... 3

1.1.3

Sound ............................................................................................................................................... 8

1.1.4

Horizontal and vertical synchronization ....................................................................................... 10

1.1.5

Luminance and chrominance signal processing ............................................................................ 13

1.1.6

Color Decoder ............................................................................................................................... 15

1.1.7

AFC - Tuning - ATS ....................................................................................................................... 18

1.2

D

IGITAL CONTROL SIGNALS

.................................................................................................................... 20

1.2.1

1-3-1 local keyboard...................................................................................................................... 20

1.2.2

1-3-2 IR remote control code ......................................................................................................... 20

1.2.3

I

2

C bus ........................................................................................................................................... 22

1.3

H

ORIZONTAL DEFLECTION 

- FBT ........................................................................................................... 24

1.3.1

General description:...................................................................................................................... 24

1.3.2

Horizontal deflection ..................................................................................................................... 24

1.4

V

ERTICAL DEFLECTION

........................................................................................................................... 29

1.4.1

Z-421 circuit .................................................................................................................................. 29

1.4.2

Drive circuit part ........................................................................................................................... 30

1.5

V

IDEO AMPLIFIER AND 

ABS ................................................................................................................... 32

1.5.1

Video output amplification............................................................................................................. 32

1.5.2

ABS operation................................................................................................................................ 34

1.5.3

Beam current limiter...................................................................................................................... 35

1.5.4

Euro-scart ...................................................................................................................................... 36

1.6

P

OWER SUPPLY 

STR-S5707.................................................................................................................... 37

1.6.1

Vin terminal, start-up circuit.......................................................................................................... 37

1.6.2

Oscillator, F/B terminal voltage (pin 7)......................................................................................... 37

1.6.3

Function of INH terminal (pin 6), control of off-time.................................................................... 37

1.6.4

Drive circuit................................................................................................................................... 37

1.6.5

OCP function ................................................................................................................................. 37

1.6.6

Latch Circuit.................................................................................................................................. 38

1.6.7

Thermal shutdown circuit .............................................................................................................. 38

1.6.8

Over-voltage protection circuit...................................................................................................... 38

1.6.9

Stand-by Mode TOP210................................................................................................................. 38

1.6.10

CONTROL PIN (pin4) ................................................................................................................... 38

2

VCR PART ................................................................................................................................................... 39

2.1

KEY FEATURES OF VIDEO IC AND ITS RELATIVES.................................................................... 39

2.2

RECORD AND PLAYBACK PROCESSING CIRCUIT ..................................................................... 40

2.2.1

RECORD PROCESSING............................................................................................................... 40

2.2.2

PLAYBACK PROCESSING ........................................................................................................... 43

2.2.3

AUDIO SIGNAL PROCESSING (LA71511M) .............................................................................. 46