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JVC GR-D23EK Service Manual page 25

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CHARTS AND DIAGRAMS
NOTES OF SCHEMATIC DIAGRAM
Safety precautions
The Components identified by the symbol
critical for safety. For continued safety, replace safety
critical components only with manufacturer's recom-
mended parts.
1. Units of components on the schematic diagram
Unless otherwise specified.
1) All resistance values are in ohm. 1/6 W, 1/8 W (refer to
parts list).
Chip resistors are 1/16 W.
K: K (1000 ), M: M (1000K )
2) All capacitance values are in µF, (P: PF).
3) All inductance values are in µH, (m: mH).
4) All diodes are 1SS133, MA165 or 1N4148M (refer to parts
list).
Note: The Parts Number, value and rated voltage etc. in
the Schematic Diagram are for references only.
When replacing the parts, refer to the Parts List.
2. Indications of control voltage
AUX : Active at high.
AUX or AUX(L) : Active at low.
3. Interpreting Connector indications
1
Removable connector
2
3
1
Wire soldered directly on board
2
3
1
Non-removable Board connector
2
3
1
2
Board to Board
3
4
Connected pattern on board
The arrows indicate signal path
Note: For the destination of each signal and further line
connections that are cut off from the diagram,
refer to "BOARD INTERCONNECTIONS"
4. Voltage measurement
1) Regulator (DC/DC CONV) circuits
REC : Colour bar signal.
are
PB
: Alignment tape (Colour bar).
: Unmeasurable or unnecessary to measure.
2) Indication on schematic diagram
Voltage Indications for REC and PB mode on the sche-
matic diagram are as shown below.
1
2
3
REC mode
2.5
1.8
(5.0)
PB and REC modes
(Voltage of PB and REC modes
PB mode
are the same)
Note: If the voltages are not indicated on the schematic
diagram, refer to the voltage charts.
5. Signal path Symbols
The arrows indicate the signal path as follows.
NOTE : The arrow is DVC unique object.
Playback signal path
Playback and recording signal path
Recording signal path
(including E-E signal path)
Capstan servo path
Drum servo path
(Example)
R-Y
Playback R-Y signal path
Y
Recording Y signal path
6. Indication of the parts for adjustments
The parts for the adjustments are surrounded with the circle as
shown below.
7. Indication of the parts not mounted on the circuit board
"OPEN" is indicated by the parts not mounted on the circuit
board.
R216
OPEN
CIRCUIT BOARD NOTES
1. Foil and Component sides
1) Foil side (B side) :
Parts on the foil side seen from foil face (pattern face)
are indicated.
2) Component side (A side) :
Parts on the component side seen from component face
(parts face) indicated.
2. Parts location guides
Parts location are indicated by guide scale on the circuit board.
REF No.
LOCATION
IC
IC101
B C
B : Foil side
(A : Component side)
C : Chip component
D : Discrete component)
Note: For general information in service manual, please
refer to the Service Manual of GENERAL INFORMA-
TION Edition 4 No. 82054D (January 1994).
2-1
2-2
Category : IC
6 A
Horizontal "A" zone
Vertical "6" zone

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