Hitachi C21-RF80S - 21" CRT TV User 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

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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
23
4
1:ANODE
2:CATHODE
3:EMITTER
4:COLLECTOR
IC 602 (Photo Transistor ) TLP621
IC BLOCK DIAGRAM
TLP621

-10-
IC 701 ( TDA93XXPS/N2/5ITV Signal Processor-Teletext )
IC BLOCK DIAGRAM

-11-
IC 861 ( TDA9874AHDigital TV Sound Demodulator/Decoder)
IC BLOCK DIAGRAM

C1651C
BCE
C2216
C
BE
CB
E
C2230
CB
E
C2482
CB
E
C2703
CB
E
B774
CB
E
C1815
CB
E
B420
CB
E
B421
CB
E
CB
E
A1015
PNP PNP
NPN
NPN
PNP
C2120
CB
E
PNP
C2717
C
BE
NPN NPN
L7805
INPUT
GND
OUTPUT
L7812
INPUT
GND
OUTPUT
L7808
INPUT
GND
OUTPUT
A1013
NPN NPN NPN
PNP
-12-
CB
E
A966
PNP
TRANSISTOR MARK

MAIN PCB TOP LAYER
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MAIN PCB BOTTOM LAYER
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AV TERMINALS PCB LAYOUT
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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.

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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.

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Item Display String
Receive 60HZ cross hatch pattern. Press PIC. MODE key to set picture in STANDARD mode.
Adjust 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 60HZ monoscope pattern.Press PIC. MODE key to set picture in STANDARD mode.
Adjust VAMP to obtain picture s vertical redisplay ratio more than 90% in factory mode.
SERVICE ADJUSTMENTS
screen in factory
Adjust HSHIFT to obtain picture s horizontal center at the center of CRTmode.
Vertical slope 60Hz VSLOPE
Vertical shift 60Hz VSHIFT
S-correction 60Hz
VAMP
Horizontal shift 60Hz
VSCOR
Vertical amplitude 60Hz
HSHIFT
OSD Position Adjustment
Menu OSD position adjustment: Receive 50/60HZ cross hatch pattern. Press PIC.MODE
key to set picture in STANDARD mode . Press KEY 5 infactory mode, adjust OSD VPOS
And OSD HPOS item to obtain menu OSD at the center of CRT screen.
White Balance Adjustment (Applied in factory)(KEY 9 )
Normally, this TV can auto adjust white balance, but for some CRT maybe need to adjust white
balance manually. Set BRIGHTNESS and CONTRAST at normal status , receive
enter factory mode. Press and set BD at 31.Adjust RD and GD to obtain white balance.
GREY SCALE and
RF.AGC Adjustment(KEY 7 )
Receive 60dB RF signal. Connect Digital voltmeter positive terminal to tuner AGC terminal
and negative terminal to GND.
Enter the AGC item in factory mode by the REMOTE CONTROL.
Method: Press key to enter factory mode, then press
and select AGC item by
Adjust keys to obtain 2.8V digital voltage meter reading or till no NOISE
on screen.
Press RECALL key to exit factory mode.
KEY 9
KEY 7 P+P -
and
+
and
SOUND MODE CH I/II
,,
RECALL
.
RF

This appendix showsinformation about serviceitems that areavailable. The tablelists all possible
available service items.
Service items
1.Press keys on remote control unit to enter factory mode.
2.Press the Direct key buttons on the remote control unit specified in the table to access directly
into the respective items when in factory mode.
3.Select the item using the keys and adjust using the keys.
4.Press RECALL key to exit factory mode.
SERVICE ADJUSTMENTS
P+P -
and +
and
SOUND MODE CH I/II
,,
RECALL
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SERVICE ADJUSTMENTS