Sony HCD-EC68 / HCD-EC78 / MHC-EC68 / MHC-EC78 Service Manual ▷ View online
HCD-EC68/EC78
21
[FM Auto Stop Check]
generator
SET
+
75
Ω
Procedure :
1. Turn the power on.
2. Input the following signal from Signal Generator to FM an-
1. Turn the power on.
2. Input the following signal from Signal Generator to FM an-
tenna input directly.
* Carrier Freq : A = 87.5 MHz, B = 98 MHz, C = 108 MHz
Deviation : 75 kHz
Modulation : 1 kHz
ANT input : 35 dBu (EMF)
Note: Please use 75 ohm “coaxial cable” to connect SG and the set. You
cannot use video cable for checking.
Please use SG whose output impedance is 75 ohm.
3. Set to FM tuner function and scan the input FM signal with
automatic scanning.
4. Confi rm that input Frequency of A, B and C detected and auto-
matic scanning stops.
The stop of automatic scanning means “The station signal is re-
ceived in good condition”.
Adjustment Location and Connecting Points:
IC801
CN801
ANTENNA
ANTENNA
36
1
3
1
19
18
IC801 pin XL
(TUNER VT)
(TUNER VT)
IC801 pin RT
(TUNER OUT L-ch)
(TUNER OUT L-ch)
– MAIN Board (Conductor Side) –
L802
FM Detector
Adjustment
Adjustment
– MAIN Board (Component Side) –
L803
FM Frequency
Coverage Adjustment
Coverage Adjustment
L801
FM Frequency
Coverage Adjustment
Coverage Adjustment
L805
AM Tracking
Adjustment
Adjustment
JW801
(TUNER-GND)
(TUNER-GND)
L804
AM Tracking
Adjustment
Adjustment
HCD-EC68/EC78
22
MEMO
HCD-EC68/EC78
HCD-EC68/EC78
23
23
For Schematic Diagrams.
Note:
• All capacitors are in μF unless otherwise noted. (p: pF)
50 WV or less are not indicated except for electrolytics
• All capacitors are in μF unless otherwise noted. (p: pF)
50 WV or less are not indicated except for electrolytics
and tantalums.
• All resistors are in
Ω and
1
/
4
W or less unless otherwise
specifi ed.
• f :
internal
component.
• 2 : nonfl ammable resistor.
• C : panel designation.
• C : panel designation.
THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed in each block.)
(In addition to this, the necessary note is printed in each block.)
• A : B+ Line.
• B : B– Line.
• C : adjustment for repair.
• Voltages and waveforms are dc with respect to ground
• B : B– Line.
• C : adjustment for repair.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
– CD Board –
no mark : CD PLAY
– DECK Board –
no mark : TAPE PLAY
( ) : TAPE REC
– Other Boards –
no mark : TUNER (FM/AM)
( ) : TAPE PLAY
< > : TAPE REC
{ } : CD PLAY
• Voltages are taken with a VOM (Input impedance 10
no mark : CD PLAY
– DECK Board –
no mark : TAPE PLAY
( ) : TAPE REC
– Other Boards –
no mark : TUNER (FM/AM)
( ) : TAPE PLAY
< > : TAPE REC
{ } : CD PLAY
• Voltages are taken with a VOM (Input impedance 10
M
Ω).
Voltage variations may be noted due to normal production
tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal production
Voltage variations may be noted due to normal production
tolerances.
• Circled numbers refer to waveforms.
• Signal path.
F :
F :
FM
f :
AM
J
: CD PLAY
E :
TAPE
PLAY
j :
REC
i : AUDIO IN
• Abbreviation
AR :
AR :
Argentina
model
AUS :
Australian
model
E2
: 120V AC area in E model
E3
: 240V AC area in E model
E51
: Chilean and Peruvian models
MX
: Mexican model
RU :
Russian
model
For Printed Wiring Boards.
Note:
• X : Parts extracted from the component side.
• Y : Parts extracted from the conductor side.
• W : indicated side identifi ed with part number.
• f : Internal component.
•
• X : Parts extracted from the component side.
• Y : Parts extracted from the conductor side.
• W : indicated side identifi ed with part number.
• f : Internal component.
•
: Pattern from the side which enables seeing.
(The other layers' patterns are not indicated.)
• Indication of transistor.
C
B
These are omitted.
E
Q
• Circuit Boards Location
KEY POWER board
PANEL board
DECK board (except EC68:UK)
MAIN board
HI AMP board (EC78)
LOW AMP board
PT board
REG board
JACK board
KEY CD board
CD board
B
These are omitted.
C E
Q
The components identifi ed by mark 0 or dotted line with
mark 0 are critical for safety.
Replace only with part number specifi ed.
mark 0 are critical for safety.
Replace only with part number specifi ed.
Caution:
Parts face side:
(Conductor Side)
Pattern face side:
(Component Side)
Parts face side:
(Conductor Side)
Pattern face side:
(Component Side)
Parts on the parts face side seen from
the pattern face are indicated.
Parts on the pattern face side seen from
the parts face are indicated.
the pattern face are indicated.
Parts on the pattern face side seen from
the parts face are indicated.
SECTION 7
DIAGRAMS
HCD-EC68/EC78
HCD-EC68/EC78
24
24
R150
R149
R148
R108
R154
R153
C148
C1
10
C109
C301
C303
C302
C104
R1
10
C1
16
C404
R203
R204
R205
R206
R207
R208
R209
R210
R219
R223
R222
R147
R221
R218
R146
R145
C150
R113
C403
R202
C151
C108
C105
C147
C146
C145
C152
C1
18
C1
17
C144
C101
C125
CN201
C143
C120
R144
R157
C142
C141
C140
C100
C107
R408
R156
C124
C127
C126
CN301
R101
C1
19
C102
R415
R414
C103
R405
C113
R102
R402
R105
R106
C132
C138
C137
R135
R134
R136
R130
R128
R129
R143
R139
C136
R120
R114
C153
C112
R125
R126
C149
C139
R127
R1
18
R140
R151
C122
C123
R220
R104
S201
R155
C128
C106
C201
R304
R302
C30
9
C20
5
C207
C307
R303
C133
R111
R112
C115
R21
1
Q30
1
R301
C204
C202
C206
C306
R212
C401
C130
X102
C405
IC201
IC401
IC101
R201
R142
CD BOARD
(COMPONENT SIDE)
CD BOARD
(CONDUCTOR SIDE)
3
1
4
5
1
7
8
14
28
22
21
15
TP124
(VC)
TP121
(RFI)
1
25
26
50
51
75
76
100
1
21
M
MAIN
BOARD
CN608
16
1
1-872-135-
11
(11)
1-872-135-
11
(11)
OPTICAL PICK-UP BLOCK
(KSM-213DCP)
A
B
C
D
E
F
1
2
3
4
5
6
7
8
9
E
(LIMIT)
M401
(SPINDLE)
M402
(SLED)
M
M
7-1. PRINTED WIRING BOARD - CD Board -
•
: Uses unleaded solder.
• See page 23 for Circuit Boards Location.
(Page 27)
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