Hitachi C21-RF80S, C21-RF80SN, C21-RF80SNT Service Manual

SERVICE MANUAL

PAL/SECAM/NTSC

CAUTION:

Before servicing this chassis, it is important that the
service technician read the Important Safety Note
in this Service Manual.

SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT

COLOUR TELEVISION

OCT 2003 Digital Media System Group, Hitachi Asia Ltd.

SC

Number : 0009E

3P31 Chassis

"

"

C21-RF80S/SN/SNT

Destination Code

O81 O51 751

19* 201 433
98* 121

-3--3-

TECHNICAL SPECIFICATION

-4-

TECHNICAL SPECIFICATION

-5-

E

CHASSIS BLOCK DIAGRAM

-6-

IC 121 (Universal HI-FI Audio Processor) TDA9859

IC BLOCK DIAGRAM

IC 161 TDA8944J(BTL Audio Amplifier)

-7-

IC 401 (Vertical Deflection Booster) STV9302A

IC BLOCK DIAGRAM

-8-

IC 601 (Power Switch) KA5Q0765RTH

IC 501(Video Output Amplifier) TDA6107Q

IC BLOCK DIAGRAM

7

-9-

1

INPUT

2

OUTPUT

SERIES
PASS
ELEMENT

SOA
PROTECTION

REFERENCE
VOLTAGE

ERROR
AMPLIFIER

THERRMAL
PROTECTION

STARTING
CIRCUIT

CURRENT
GENERATOR

REFERENCE
VOLTAGE

3

GND

IC 653 & IC 181& IC 652 (Regulators) L7800 Series

1

2

3

4

1:ANODE
2:CATHODE
3:EMITTER
4:COLLECTOR

IC 602 (Photo Transistor ) TLP621

IC BLOCK DIAGRAM

TLP621

-10-

IC 701 ( TDA93XXPS/N2/5I TV Signal Processor-Teletext )

IC BLOCK DIAGRAM

-11-

IC 861 ( TDA9874AH Digital TV Sound Demodulator/Decoder)

IC BLOCK DIAGRAM

C1651C

B

C

E

C
2

2
1
6

C

B

E

C

B

E

C22

3
0

C

B

E

C
2
482

C

B

E

C270

3

C

B

E

B
7
7
4

C

B

E

C
1
8
1

5

C

B

E

B
4
2
0

C

B

E

B
4
2
1

C

B

E

C

B

E

A10

1
5

PNP

PNP

NPN

NPN

PNP

C
2
1
2

0

C

B

E

PNP

C
2
7
1

7

C

B

E

NPN

NPN

L7805

INPUT

GND

OUTPUT

L7812

INPUT

GND

OUTPUT

L7808

INPUT

GND

OUTPUT

A10

1
3

NPN

NPN

NPN

PNP

-12-

C

B

E

A96

6

PNP

TRANSISTOR MARK

MAIN PCB TOP LAYER

-13-

MAIN PCB BOTTOM LAYER

-14-

AV TERMINALS PCB LAYOUT

-15-

Side AV Terminals PCB Layout

Control Panel PCB Layout

Remote Control Unit PCB Layout

-16-

Tools And Equipment For Adjustment

Before Servicing The TV Set

SERVICE ADJUSTMENTS

ALIGNMENT INSTRUCTION (3P31)

The main power is 100~240V 50/60HZ . Please be careful when you are servicing.

Don t short any two soldering points, which should not be shorted and don t touch any
components, which should not be touched.

Please disconnect the power plug form the wall outlet before servicing.

For safety reasons, all components replaced should be identical with BOM.

Before alignment, ensure the TV set has heat run for at least 30 minutes and degauss the
CRT thoroughly with demagnetizer.

The data of EEPROM must be stored before the adjustment for main chassis.

Small - Screwdriver Without Inductance

Pattern Generator
DC Regulated power supply

Digital Voltmeter

Sweep Signal Generator

20MHz 2-channel Oscilloscope

Power Adjustment

Connect a 100W bulb across C616 and AC 200V power to CN601. If the bulb lights

up,the voltage is normal and power is ok, else please proceed servicing.

-17-

Press PIC. MODE key to set picture in STANDARD mode at no signal input.

Item

Display String

General Adjustment

Press keys on remote control unit to enter
factory mode.

Press 0-9 numeric keys to enter factory menu.

Select the item using the keys and adjust using the keys.

Press key to exit factory mode.

Enter factory mode

Focus Adjustment

Receive monoscope pattern.

Press PIC.MODE key to set picture in DYNAMIC mode.

Adjust the focus knob of FBT to get the clearest picture.

Screen Voltage Adjustment(Key 9)

Press key in turn to enter factory mode.

Press 0 key and a horizontal line will display on the screen.

Adjust the screen knob of FBT so that the horizontal line is just visible.

Press other keys to go to the normal work status.

Vertical Size And Pin Cushion Adjustment (Key 8)

Receive 50HZ cross hatch pattern.

VSLOPE to obtain half of the crosshatch. Adjust VSCOR to obtain picture s

best vertical pin cushion. Adjust VSHIFT to obtain picture s vertical center at the center

of CRT screen in factory mode.

Receive 50HZ monoscope pattern.

Press PIC. MODE key to set picture in STANDARD

mode. Adjust

Press PIC. MODE key to set picture in STANDARD

mode. Adjust VAMP to obtain picture s vertical overscan more than 90% in factory mode.

Vertical slope 50Hz

VSLOPE

Vertical shift 50Hz

VSHIFT

S-correction 50Hz

VAMP

Horizontal shift 50Hz

VSCOR

SERVICE ADJUSTMENTS

P+

P -

+

and

and

SOUND MODE

CH I/II

,

,

RECALL

RECALL

SOUND MODE

CH I/II

,

,

RECALL

Vertical amplitude 50Hz

HSHIFT

Adjust HSHIFT to obtain picture s Horizontal center at the

center of CRT screen in factory mode.