Casio TV-770B Service manual

TV-770B (KX-503B)

INDEX

(For NTSC)

JUN. 1996

(without price)

CH 2 4 5 6 7 11 13
CH 14 30 40 50 60 69

TV-770B

R

CONTENTS

SPECIFICATIONS ......................................................................................... 1

BLOCK DIAGRAM ........................................................................................ 2

PRINTED CIRCUIT BOARDS ....................................................................... 3

EXPLODED VIEW ......................................................................................... 5

PARTS LIST .................................................................................................. 6

IC AND TRANSISTOR LEAD IDENTIFICATION ........................................ 10

SCHEMATIC DIAGRAMS ........................................................................... 13

WAVEFORMS.............................................................................................. 15

SPECIFICATIONS

Item Specification

1. Reception channels VHF: 2 ~ 13 ch UHF: 14 ~ 69 ch

2. Power voltage DC 6.0 V

3. Power consumption Approx. 3.6 W

4. Current consumption Approx. 600 mA

5. Battery life (with alkaline batteries) Approx. 4.0 hours

Batteries : 4 × LR6 (D) size batteries

6. Power supply Car adaptor : CA-K65
AC adaptor : AD-K64, 65

Earphone jack : 3.5 ø mini

7. Connection terminals External power jack : 6.0 V DC IN
External antenna jack : 3.5 ø mini

8. Screen size 2.3 inches

9. No. of picture element 39,600 (110 × 360) dots

10. Dimensions 127 mm (H) × 81 mm (W) × 35 mm (D)

11. Weight 200 g without batteries

AC adaptor : AD-K64, 65

12. Options Car adaptor : CA-K65
Antenna matching device : AS-35S

— 1 —

Antenna

BLOCK DIAGRAM

Power
Supply

1 TU200 2 Q200

IF Amp.Tuner

IC500

7

Tuning
Voltage
Generator

VCC2 (3.95 ± 0.02 V)
VCC7 (34.2 ~ 41.8 V)
VEE1 (–6.1 ~ –7.3 V)

VR800

Brightness
Control

3 IC200

Video
Sound Det.
FM
AFT Circuit
AGC Circuit

5

6

Osc.
Display
Control
A-D Converter
Auto-Tuning
Control

Det

IC300

Chroma
Circuit

IC700

VR600

Volume
Control

8 Q800~Q803, Q805, Q806

Display
Voltage
Generator

4 IC600 Speaker

Audio
Amp.

Common
Driver

LCD

Segment
Driver

1 — Color tuner: TU200 TEPU5-02

Selects a desired radio wave and changes it to the video IF signal.

2 — Video IF amp.: Q200 2SC4238

Amplifies the video IF signal output from tuner TU200 by 10 times (20 dB).

3 — Video det./Sound det./FM det./AFT/AGC: IC200 M51348FP

Eliminates the carrier wave in the video IF signal, and picks up the video signal and the sound IF signal.
Also, the sound signal is picked up from the sound IF signal by FM detection.

4 — Audio amp.: IC600 NJM2070M

Sound amplification.

5 — Chroma circuit: IC300 M52042FP

Generates the tricolor (red, green, and blue) from the video signal.

6 — Osc./A-D converter/display control/auto-tuning control: IC700 MSM6625-02 GSK-640F

Converts the color signal into a digital signal.
Also, generates the clock pulse for the display and controls the display.

7 — Tuning voltage generator: IC500 MSC1169MS-K

Generates the tuning voltage with the tuning pulse output from 6.

8 — Display voltage generator: Q800~Q803, Q805, Q806, 2SD601A-R x 4, 2SB709A-R, 2SD1149-S

Generates the display voltages V0 ~ V4 with VEE1 and VCC7 outputs from the power supply.

— 2 —

TOP VIEWS
Linear

PRINTED CIRCUIT BOARDS

SW100

C105

FU100

JK100

VR100

R840

Q110

R113

R704

D155

D180

Q101

C115

TU200

C236

R110
R108

C140

R115

T100

C112

JK200

C113

C603

C202

C208

C207

F200

C205

CN710

C100

C110

D150

L101

R738

C606

C249

R224

D707

JK600

VR301

C210

R226

F211

F210

R252

R253

R222

R209

L102

R251

R223

VR700

L103

R335
R336

C245
R212

C750

R305

F203

VR200

R236
C259

R257

R808

R809

IC700

C309

C330

R306

C281
R254

C780

R810

C270

L202

C263 C262

C800

C351

C346

C742

T200

T201

C808

C700

H300

R322

C741

C806

D805

D803

C740

R261

R830

VR300

F221

R255
R256

F220

R816

R820

R745

C782

VR600

VR800

C305

R310

C340

R813

CN700

Back Light

L950

CN950

C925

— 3 —

T950

C927

BOTTOM VIEWS
Linear

C335

R260 R258

R331 R330

R307
R707C730

R706 C282

Q230

R259

C837

R815

R814

C840

C836

Q801

IC300

C345

SW200

VCC2-3

C350

C348

COL

C347

Q300

C272

C264

R239

HD

Q802 Q803

Q800

R247

R246

C261R241

R116

R326
R325

HP210

ATT

R225

C-SYNC

AFT

BR

OR

AUDIO

VIDEO

IC200

BM

R645

CP244

C230
R210

R208
C243

C246

CP330

R211

VCC1-1

BT

BV

C233

CP200

BU

R150

C242

C240

RF

BS

IF

C237 R203

HP200

C238

Q200

H/L

C265 C642

R610
R611C250

R641

C635

C545 C234

R545 C535

R541

C231

C200
R201

R202 R207

R205

R204

HP701

TU

C630

R503 C530

C232

C550

L200

IC500

D500
R550

C239

IC600

CP590

C641

R500 R501 R502

R607

R606

Back Light

G

R615

R825

R

C770

C841

D800

L710

VCC2-8

Q806

Q805

R727
R726
R725

R827
R833

D705

C760

C830

R800

R803

R733

C756

R730

C751

C755

L705

C758

VEEI

PD

C761

D703

R700

KDB

R709

HP700

R718

VCC2

R710
R711

R719

B

C150

GND

C130

C765

D152

C153

CP990

VCC7

Q111

R106
R107
C137

C145

VCC2-0

C155

C152

C160

HP906HP905

R105

D110

TM100

D100

C182

C185

Q951

Q950

R950

R746

— 4 —

CP900

SW700

C783

CP902

SW710