JVC AV-21L81B(-VT), AV-25L81B(-VT) Schematics
AV-21L81B
AV-25L81B
SCHEMATIC DIAGRAMS
COLOUR TELEVISION
BASIC CHASSIS
CH
AV-21L81B
AV-25L81B
CD-ROM No. SML200111
POWER
DISPLAY
MENU
SUPER
BASS
CHANNEL VOLUME
SYSTEM
SOUND MUTING
COLOUR
TV/VIDEO
123
456
PICTURE MODE
7809
CHANNEL SCAN
RETURN
-/--
OFF TIMER
ECO SENSOR
RM-C356 REMOTE CONTROL UNIT
RM-C356-1C
(-VT)
(-VT)
COPYRIGHT © 2001 VICTOR COMPANY OF JAPAN, LTD.
No. 51903
Sep. 2001
AV-21L81B (-VT)
AV-21L81B
AV-25L81B
AV-25L81B (-VT)
q
NOTE ON USING CIRCUIT DIAGRAMS
STANDARD CIRCUIT DIAGRAM
1. SAFETY
The components identified by the symbol and shading are
critical for safety. For continued safety replace safety critical
components only with manufactures recommended parts.
2. SPECIFIED VOLTAGE AND WAVEFORM VALUES
The voltage and waveform values have been measured under the
following conditions.
(1) Input signal : Colour bar signal
(2)
Setting positions of each knob/button and variable resistor
: Original setting position when
shipped
(3) Internal resistance of tester : DC 20kØ/V
(4) Oscilloscope sweeping time : H ⇒ 20µS/div
:V ⇒ 5mS/div
: Others ⇒ Sweeping time is
specified.
(5) Voltage values : All DC voltage values
9Since the voltage values of signal circuit vary to some extent ac-
cording to adjustments, use them as reference values.
3. INDICATION OF PARTS SYMBOL [EXAMPLE]
• In the PW board : R1209
→
R209
Type
•
No indication : Ceramic capacitor
MY : Mylar capacitor
MM : Metalized mylar capacitor
PP : Polypropylene capacitor
MPP : Metalized polypropylene capacitor
MF : Metalized film capacitor
TF : Thin film capacitor
BP : Bipolar electrolytic capacitor
TAN : Tantalum capacitor
(3) Coils
No unit : [µH]
Others : As specified
(4) Power Supply
:B1
: B2(12V)
:9V
:5V
9Respective voltage values are indicated
(5) Test point
: Test point
: Only test point display
4. INDICATIONS ON THE CIRCUIT DIAGRAM
(1) Resistors
Resistance value
•
No unit : [Ø]
k:[kØ]
M:[MØ]
Rated allowable power
•
No indication : 1/10 [W]
Others : As specified
Type
•
No indication : Carbon resistor
OMR : Oxide metal film resistor
MFR : Metal film resistor
MPR : Metal plate resistor
UNFR : Non-Flammable resistor
FR : Fusible resistor
9Composition resistor 1/2 [W] is specified as 1/2S or Comp.
(2) Capacitors
Capacitance value
•
1 or higher : [pF]
less than 1 : [µF]
Withstand voltage
•
No indication : DC50[V]
AC indicated : AC withstand voltage [V]
Others : DC withstand voltage [V]
9 Electrolytic Capacitors
47/50[Example] : Capacitance value [µF]/withstand voltage[V]
(6) Connecting method
: Connector
: Wrapping or soldering
: Receptacle
(7) Ground symbol
: LIVE side ground
: ISOLATED(NEUTRAL) side ground
: EARTH ground
: DIGITAL ground
5. NOTE FOR REPAIRING SERVICE
This model’s power circuit is partly different in the GND. The difference
of the GND is shown by the LIVE : ( ) side GND and the
ISOLATED(NEUTRAL) : ( ) side GND. Therefore, care must be taken
for the following points.
(1) Do not touch the LIVE side GND or the LIVE side GND and the
ISOLATED(NEUTRAL) side GND simultaneously. If the above caution is not respected, an electric shock may be caused. Therefore,
make sure that the power cord is surely removed from the receptacle when, for example, the chassis is pulled out.
(2) Do not short between the LIVE side GND and ISOLATED(NEUTRAL)
side GND or never measure with a measuring apparatus ( oscilloscope, etc.) the LIVE side GND and ISOLATED(NEUTRAL) side
GND at the same time. If the above precaution is not respected , a
fuse or any parts will be broken.
Since the circuit diagram is a standard one, the circuit and cir-
•
cuit constants may be subject to change for improvement without any notice.
Sep. 2001 No. 51903
AV-21L81B
AV-25L81B
CONTENTS
SEMICONDUCTOR SHAPES ................................................................................................................................. 2-2
BLOCK DIAGRAM.......................................................................................................................................................... 2-3
CIRCUIT DIAGRAMS
MAIN PWB CIRCUIT DIAGRAM (1/2) ................................................................................................................ 2-5
MAIN (2/2) AND CRT SOCKET PWB CIRCUIT DIAGRAMS ...................................................................................... 2-7
PATTERN DIAGRAMS
MAIN PWB PATTERN......................................................................................................................................................... 2-9
CRT SOCKET PWB PATTERN ....................................................................................................................................... 2-11
SEMICONDUCTOR SHAPES
TRANSISTOR
TOP VIEWBOTTOM VIEW FRONT VIEW
CHIP TR
E
C
B
ECB
EC
B
(G)(D)(S)
ECB
ECB
C
B
E
IC
CHIP IC
TOP VIEWBOTTOM VIEW FRONT VIEW
OUT
E
IN
IN E OUT
N
N
N
1
N
1N
TOP VIEW
1
N
1N
1N
2-2 No.51903
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