Casio TV-600B Service manual

(with price)

INDEX

POCKET TELEVISION

TV-600B

DECEMBER 1994

Page

Specifications.............................................................................................1

Block Diagram ...........................................................................................2

Circuit Description......................................................................................3

Adjustment

Linear PCB..........................................................................................5

A/D PCB..............................................................................................9

Troubleshooting.......................................................................................10

Printed Circuit Boards..............................................................................11

Wiring Diagram........................................................................................15

Exploded View / Disassembly..................................................................16

Electrical Parts List ..................................................................................17

Mechanical Parts List...............................................................................23

IC and Transistor Lead Identification .......................................................24

Schematic Diagrams and Waveforms .....................................................26

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. 3.4 W

4. Current consumption Approx. 566 mA

5. Battery life (with alkaline batteries) Approx 3.0 hours

Batteries : 4 AA size batteries

6. Power supply Car adaptor : CA-K65 AC adaptor : ADK-65, 64

Earphone jack : 3.5ø mini

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

8. Screen size 2.2 inches

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

10. Dimensions 81 (W) × 32 (D) × 131 (H) mm 3 1/5" (W) × 1 1/4" (D) × 5 1/6" (H)

11. Weight 220 g excepting batteries

7.8 oz excepting batteries

12. Standard accessories Test batteries (R6 × 4)

AC adaptor : AD-K65, 64

13. Options Car adaptor : CA-K65 RF connector : CF-13 Antenna matching device : AS-35S

14. Body color Black

— 1 —

Antenna

BLOCK DIAGRAM

Power Supply

1 TU200 2 Q200

IF Amp.Tuner

IC500

Tuning Voltage Generator

VCC2 (3.95±0.02 V) VCC6 (30.5~39.0 V) VCC7 (53.5~72.5 V) VEE1 (–6.3~–7.9 V)

VR800

Brightness Control

3 IC200

Video Sound Det. FM AFT Circuit AGC Circuit

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

Det

IC300

Chroma Circuit

IC700

VR600

Volume Control

8 Q800~Q802, Q804~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 the tuner TU 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 (TU) output from 6.

8 — Display Voltage Generator: Q800~Q802, Q804~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 —

CIRCUIT DESCRIPTION

TUNING VOLTAGE GENERATOR

BT BS

Vcc

VCC6

IC500 MSC1169MS-K

OUT

H/L

TU H/L BU

U/V

VREFU1U2

VL1

VL2

VH1

VH2

GND

VREF

R500R501R502

GND

Figure 1

This circuit generates the DC tuning voltage BT for selecting a channel with a TU pulse being output from IC700.

IC500 has 3 circuits for converting pulses to voltages; it selects one of VHF-L, VHF-H, or UHF, and causes the tuning voltage to be output from the OUT terminal (pin 12). Figure 2 and Table 1 show the conditions for selection.

IC500

VHF

-L

VHF

-H

UHF

910

U/V H/L

Figure 2

OUT(BT)

— 3 —

Inputs

U/V

L H H

H/L

VHF-L receiving

VHF-H receiving

UHF receiving

Table 1

Function

POWER SUPPLY

Vref

VCC1-1

C100

D100

C105

CP100

VR100

R101

C135

Q100

Q101

R111

R102

C140

Q111

R115

C145

R117

Figure 3

CP104

T100

GND

VCC2-2

L102

D155

D152

D150

D152

C112

L101

C110

C113

VCC2-3

R133

VCC7

CP108

VCC6

CP107

VCC2

CP109

VEE1

CP110

C115

C114

The power supply consists of a DC-DC converter and causes the voltages to be output as shown in Table 2.

Name Voltage Function

VCC2 3.95 ± 0.02 V Main voltage VCC6 30.5 ~ 39.0 V Tuning voltage VCC7 53.5 ~ 72.5 V Tuning voltage/Display voltage

VEE1 –6.3 ~ –7.9 V Display voltage

Table 2

— 4 —

ADJUSTMENT

LINEAR PCB Items To Be Adjusted

Item Measuring Instrument

VCC2 voltage setting Voltmeter Video detection coil adjustment TV signal generator, pattern generator, oscilloscope,

low-pass filter AFT coil adjustment Sweep generator, oscilloscope, voltmeter Contrast adjustment TV signal generator, pattern generator, oscilloscope AGC adjustment TV signal generator, pattern generator, IF levelmeter

Adjustment And Test Point Locations

T201 T200

Top View

— 5 —

TP7

VR100

TP5

VR300

TP2

TP1

PadIF

VR200

TP3

Bottom View

Equipment Connection / Adjustment Procedure

VCC2 Voltage Setting

TV-600

Set

TP4

Voltmeter

Output

TP1

Input Input Input Output Output

Connection Point Signal Connection Point

Adjust Result

VR100

Voltmeter

— 6 —

TP1

Adjust for 3.95 ± 0.02 V reading on voltmeter.

* Desolder the IF pad to open.

Pattern generator

Signal generator

Video Detection Coil Adjustment

TV-600

Set

Input Output

TP2

TP3

Oscilloscope

Low-pass filter

Input Input Input Output Output

Connection Point Signal Connection Point

Adjust Result

Pattern generator

Signal generator

TP2 T200 TP3

Color bar

45.75 MHz 40 ± 3 dBµ

Low-pass filter Oscilloscope

AFT Coil Adjustment

* Desolder the IF pad to open.

Sweep generator

Input

TP2

TV-600

Set

Oscilloscope Voltmeter

Output

TP4

45.75±5 MHz

Sweep generator

(Sweep) Marker:

TP2 T201 TP4

45.75 MHz

Voltmeter Oscilloscope

70 ± 3 dBµ

Adjust for DC level at mini-

Adjust for 2.0 ± 0.2 V reading on voltmeter. Confirm that the marker is at the middle of S-curve on oscilloscope.

* Desolder the IF pad to open.

Pattern generator

Signal

TP2 VR300 TP5

Color bar

45.75 MHz 70 ± 3 dBµ

generator

Contrast Adjustment

Signal generator

Input Output

Oscilloscope

— 7 —

TP2

TV-600

Set Oscilloscope

TP5

Adjust step form wave to read

0.8 ± 0.05 Vp-p.

* Short the IF pads.

AGC Adjustment

Pattern generator

Signal generator

TV-600

Set

Input Output

TP7

Input Input Input Output Output

Connection Point Signal Connection Point

Adjust Result

TP2

Pattern generator

TV signal

TP7 VR200 IF levelmeter TP2

Color bar 65 ± 5 dBµ

generator

IF levelmeter

Adjust for 84 ± 2 dBµ reading on the IF levelmeter

— 8 —

A/D PCB Item to Be Adjusted

Item Measuring Instrument

Clock adjustment Voltmeter

Adjustment And Test Point Locations

TOP VIEW

TP6

Equipment Connection / Procedure

Clock Adjustment

TV-600

Set

Output

TP6

Input Input Input Output Output

Connection Point Signal Connection Point

Adjust Result

VR700

Voltmeter

TP6

VR700

Adjust for 2.05 ± 0.05 V reading on voltmeter.

— 9 —

+ 21 hidden pages