Casio TV-770B Service manual

(without price)

TV-770B (KX-503B)

(For NTSC)

JUN. 1996

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

TV-770B

INDEX

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 —

BLOCK DIAGRAM

Antenna

3IC200

1 TU200	2 Q200	Video	4 IC600	Speaker
			VR600
		Sound DetDet.
			Audio
Tuner	IF Amp.	FM	Amp.
		AFT Circuit	Volume
		AGC Circuit	Control

7	IC500		5	IC300
Tuning
Voltage				Chroma		Common		LCD
Generator				Circuit		Driver

6IC700

				Osc.
				Display
								Segment
					Control
				A-D Converter				Driver
				Auto-Tuning
					Control
		VR800			8 Q800~Q803, Q805, Q806
Power	VCC2 (3.95 ± 0.02 V)				Display
	VCC7 (34.2 ~ 41.8 V)				Voltage
Supply
					Generator
	VEE1 (–6.1 ~ –7.3 V)	Brightness
		Control

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 —

PRINTED CIRCUIT BOARDS

TOP VIEWS

Linear

JK200

C603

JK600

L103

C309

H300

C305

C208C202C606

VR301

R335

R305

C351

VR300

R226

F211

C742

C741

C340

R336

C330

C346

R322

R310

C210

R306

TU200

C207

C249

F210

VR200

F203

L202

C270

T200

C740

F221

R252

R251

R255

R253

T201

R256

F220

R222

R236 C281

F200

R224

C263 C262

R209

C245 R257

C259 R254

R261

SW100

R223

R212

C780

R816

R813

R704

C236

C205

L102

R808

R809

C808

C806

CN710

R810

R820

CN700

C110

C100

D805

C782

C800

VR100

R110

R745

D803

R108

Q110 Q101 C140

C700

R113

R115

D150

VR600

C105

C115

C750

R830

R840

T100

D155

FU100

D180

C112

C113

VR700

IC700

JK100

L101

VR800

R738 D707

Back Light

CN950

C927

L950

C925

T950

— 3 —

BOTTOM VIEWS

Linear

		BR	R645
		VCC2-3
R331	R330	R116	C265 C642
	C350	OR

C335

C730R707R307R706

C282IC300

C348 R326

RF

C234

C535

C630

IC600

COL

R610

C641

C347 R325

CP244

C250 R611

ATT

C230

R641

Q300

R225

R247

AUDIO

R210

C635

C272

CP590

R259

C345

C264

R246

R150

C200

C231

IC500

R502R501R500

VIDEO

HP210

C545

R545

BU

R260 R258

R541

Q230

C246 BT

BS

R239

C261R241

IC200

HP200

R607

R606

C837

C242

BV

C232

R503 C530

R208

IF

R201

D500

C243

C237 R203

R550

SW200

R202 R207

R815

R814

C233

R205

C550

HD

BM

C238

AFT

CP200

L200

C239

R211

R204

CP330

Q200

C836

C840

C-SYNC

Q802

Q803

C240

Q801

HP701

Q800

VCC1-1

H/L

TU

C770	L710	D800

C841	VCC2-8

Q806

R615

R800	C830	C150
	VEEI
	R803		C130
R827		D703
R833		GND
	C751	VCC2

VCC7

R106

R105

TM100

R107

C137 C155 D110

D100

R825

R

G

Q805			C755		R700		R709		Q111
R727	R733			PD			HP700	R710
		C756						C765	D152
R726			L705					R711
R725	D705	R730	C758	C761		KDB			C153
	C760					R718	R719
								B

C145

C160

VCC2-0

C152

C182

C185

Back Light

HP905

HP906

CP990

C783

	Q950
			R950

CP900

CP902

Q951	R746	SW700	SW710

— 4 —