Hitachi C21-F880S 3P31 Schematic
9
IMPORTANT SAFETY NOTE
Maintenance and repair of this TV should be done by qualified service personnel only
when servicing the high voltage system, remove static charge from it by discharging
the picture tube (2nd anode lead) to the dag coating (picture tube grounding lead).
SAFETY PRECAUTIONS
1. An isolation transformer should be used to supply power to the TV during servicing
on the primary of the converter transformer of the set.
2.
Read and comply with all caution and safety related notes on the back cover, inside
the TV, on the PCBs and the picture tube.
3. When replacing a chassis in the cabinet, always
devices
barriers, isolation resistor-capacitor networks etc.). Before returning the television
to the customer , the service technician must ensure that it is completely safe to
operate.
are installed properly (e.g. control knobs, adjustment covers or shields,
X-RADIATION PRECAUTION
be
certain
all the protective
that
The primary source of X-RADIATION in television receiver is the picture tube. The
picture tube is specially constructed to limit X-RADIATION emissions. For
X-RADIATION protection, the replacement tube must be the same
including suffix letter. Excessive high voltage
X-RADIATION. To avoid such hazards, the high voltage must be maintained within
specified limit. Refer to this service
specific high voltage limit. If high voltage exceeds the limits, take necessary correcti v
action. Carefully follow the instructions for +B volt power supply adjustment, and high
voltage check to maintain the high voltage within the specified limits.
manual
may produce potentially hazardous
on the
high
voltage adjustment for the
type as the original
continued
PRODUCT SAFETY NOTICE
Maintenance and repair of this TV should be done by qualified service per onnel nly
Critical parts that have special safety characteristics are identified by a in the
replacement parts list or the schematic diagrams.
part that does not have the same safety characteristics
replacement
Please do not degrade the safety of this TV through improper servicing.
part in
the parts
list might create shock , fire and / or other hazards.
Use of any substitute replacement
as
the recommended
s
o
!
e
.
TECHNICAL SPECIFICATION
FREQUENCY
FS
-3--3-
TECHNICAL SPECIFICATION
-4-
CHASSIS BLOCK DIAGRAM
E
-5-
IC BLOCK DIAGRAM
IC 121 (Universal HI-FI Audio Processor) TDA9859
IC 161 TDA8944J(BTL Audio Amplifier)
-6-
IC BLOCK DIAGRAM
IC 401 (Vertical Deflection Booster) STV9302A
-7-
IC BLOCK DIAGRAM
IC 501(Video Output Amplifier) TDA6107Q
7
IC 601 (Power Switch) KA5Q0765RTH
-8-
IC BLOCK DIAGRAM
IC 602 (Photo Transistor ) TLP621
TLP621
1
2
4
3
1:ANODE
2:CATHODE
3:EMITTER
4:COLLECTOR
IC 653 & IC 181& IC 652 (Regulators) L7800 Series
INPUT
1
REFERENCE
VOLTAGE
STARTING
CIRCUIT
CURRENT
GENERATOR
REFERENCE
VOLTAGE
ERROR
AMPLIFIER
SOA
PROTECTION
THERRMAL
PROTECTION
-9-
SERIES
PASS
ELEMENT
OUTPUT
2
GND
3
IC BLOCK DIAGRAM
IC 701 ( TDA93XXPS/N2/5I TV Signal Processor-Teletext )
-10-
IC BLOCK DIAGRAM
IC 861 ( TDA9874AH Digital TV Sound Demodulator/Decoder)
-11-
TRANSISTOR MARK
PNP
E
PNP
A
1
0
1
5
E
PNP
A96
6
B
C
A10
1
3
B
E
C
PNP
B
7
7
4
B
B
C
E
C
NPN
E
NPN
E
C
C22
3
0
B
C
B
4
2
0
B
NPN
E
PNP
E
C
2
482
B
C
C
2
1
2
0
B
C
NPN
E
NPN
B
PNP
C270
B
4
2
1
NPN
C
1
8
1
5
3
B
E
B
E
C
B
C
C
NPN
C
2
2
1
6
E
C
C
2
7
1
7
B
E
C
INPUT
L7808
GND
OUTPUT
B
C1651C
C
INPUT
L7812
GND
OUTPUT
INPUT
L7805
OUTPUT
GND
E
-12-
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