Jvc AV 21T15 Service Manual

SCHEMATIC DIAGRAMS

FLAT COLOR TELEVISION

YA25420051

AV-21VT15/R

CD-ROM No.SML200504

BASIC CHASSIS

CW

COPYRIGHT © 2005 Victor Company of Japan, Limited

No.YA254

2005/4

AV-21VT15

/R

STANDARD CIRCUIT DIAGRAM

NOTE ON USING CIRCUIT DIAGRAMS

1.SAFETY

The components identified by the symbol and shading are
critical for safety. For continued safety replace safety ciritical
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

(3)Internal resistance of tester

(4)Oscilloscope sweeping time

(5)Voltage values

Since the voltage values of signal circuit vary to some extent
according to adjustments, use them as reference values.

: Original setting position
when shipped

: DC 20kΩ/V

: H

: V

: Othters

: All DC voltage values

20µs / div

5ms / div

Sweeping time is
specified

3.INDICATION OF PARTS SYMBOL [EXAMPLE]

In the PW board

: R209

R209

Type

No indication

MM
PP
MPP

MF
TF
BP

TAN

(3)Coils

No unit

Others

(4)Power Supply

Respective voltage values are indicated

(5)Test point

: Test point

(6)Connecting method

: Ceramic capacitor
: Metalized mylar capacitor

: Polypropylene capacitor
: Metalized polypropylene capacitor
: Metalized film capacitor
: Thin film capacitor
: Bipolar electrolytic capacitor
: Tantalum capacitor

: [µH]

: As specified

: B1

: 9V

: Connector

: Receptacle

: Only test point display

: Wrapping or soldering

: B2 (12V

: 5V

)

4.INDICATIONS ON THE CIRCUIT DIAGRAM

(1)Resistors

Resistance value

No unit : [Ω]

K
M

Rated allowable power
No indication : 1/16 [W]

Others : As specified

Type

No indication

OMR

MFR

MPR

UNFR

FR

Composition resistor 1/2 [W] is specified as 1/2S or Comp.

(2)Capacitors

Capacitance value

1 or higher : [pF]

less than 1

Withstand voltage

No indication : DC50[V]

Others : DC withstand voltage [V]

AC indicated
Electrolytic Capacitors

47/50[Example]: Capacitance value [µF]/withstand voltage[V]

: [kΩ]

: [MΩ]

: Carbon resistor

: Oxide metal film resistor

: Metal film resistor

: Metal plate resistor

: Uninflammable resistor

: Fusible resistor

: [µF]

: AC withstand voltage [V]

(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 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
circuit constants may be subject to change for improvement
without any notice.

NOTE
Due improvement in performance, some part numbers show
in the circuit diagram may not agree with those indicated in
the part list.
When ordering parts, please use the numbers that appear
in the Parts List.

)

(No.YA254)2-1

CONTENTS

SEMICONDUCTOR SHAPES .................................................................................................................................... 2-2

USING P.W.BOARD .......................................................................................................................................................2-2

BLOCK DIAGRAM ............................................................................................................................................................ 2-3

CIRCUIT DIAGRAMS

MAIN PWB CIRCUIT DIAGRAM (1/3) ...............................................................................................................................2-5

MAIN PWB CIRCUIT DIAGRAM (2/3),(3/3) ......................................................................................................................2-7

PATTERN DIAGRAMS

MAIN PWB PATTERN ......................................................................................................................................................... 2-9

VOLTAGE CHARTS ....................................................................................................................................................... 2-11

WAVEFORMS ................................................................................................................................................................... 2-12

SEMICONDUCTOR SHAPES

TRANSISTOR

BOTTOM VIEW FRONT VIEW TOP VIEW

CHIP TR

E
C
B

ECB

B

(G)E(S)C(D)

ECB

ECB

C

BE

IC

BOTTOM VIEW FRONT VIEW TOP VIEW

OUT

E

IN

IN OUTE

1 N

1 N

CHIP IC

TOP VIEW

1

N

1

N

USING P.W.BOARD

P.W. BOARD ASS'Y NAME

MAIN P.W. BOARD

AV-21VT15/R

SCW-1126A-H2

1

N

2-2(No.YA254)