Sony ICF-M770L / ICF-M770S / ICF-M770SL Service Manual ▷ View online
ICF-M770L/M770S/M770SL
7
7
Adjustment Location:
– MAIN BOARD (Component Side) –
– MAIN BOARD (Conductor Side) –
TP
(VT)
TP
(ANT)
CT1
MW Tracking Adjustment (M770L)
L5-1
L13
L12
L12
FM Tracking Adjustment
CT4
CT2
MW Tracking Adjustment (M770S)
L5
LW Tracking Adjustment (M770SL)
CT1
SW Tracking Adjustment (M770S/M770SL)
L3
T1
AM IF
Adjustment
L14
FM VT Voltage
Adjustment
CT3
LW VT Voltage
Adjustment (M770L)
L8
MW VT Voltage Adjustment (M770L)
SW VT Voltage Adjustment (M770S/M770SL)
SW VT Voltage Adjustment (M770S/M770SL)
L10
MW VT Voltage Adjustment (M770S)
LW VT Voltage Adjustment (M770SL)
LW VT Voltage Adjustment (M770SL)
CT2
LW Tracking Adjustment (M770L)
L5-2
ICF-M770L/M770S/M770SL
8
8
SECTION 5
DIAGRAMS
5-1.
BLOCK DIAGRAM
13
10
15
18
11
6
8
FM
FRONT-END
FM
IF AMP
AF
POWER AMP
AM IF AMP,
AGC, DET
AM
FRONT-END
17
20
FM
RF IN
RF IN
FM/AM
IF OUT
CF3
10.7MHz
CF2
10.7MHz
CF1
450kHz
FM
RF
RF
FM
IF IN
IF IN
TUNING METER
28
AF
OUT
AF
IN
IN
24
25
DET
OUT
AM
IF IN
IF IN
METER
NF
VOL
16
4
5
FM/AM
BAND
SELECT
AM OSC
L8
SW/MW
OSC
L10
MW/LW
OSC
L14
FM OSC
L5
MW/LW
FERRITE-ROD
ANTENNA
FM OSC
AM
RF IN
RF IN
L12, 13
FM RF
FM/AM FRONT-END,
FM/AM IF AMP, DET, AGC, AF AMP
IC1
SYSTEM CONTROLLER,
LIQUID CRYSTAL DISPLAY DRIVER,
KEY CONTROL
IC104
CT2
D2-1
Q6
MW/LW
SWITCH
MW/LW
SWITCH
Q4
MW/LW
SWITCH
Q7
CT3
CT4
RV1
VOL
+
+
L14
FM VT VOLTAGE
D104, 105
(LCD BACK LIGHT)
CT3
LW VT
VOLTAGE
L10
LW VT
VOLTAGE
CT4, L12, 13
FM TRACKING
T1
AM IFT
T1
AM IF
B.P.F.
BPF1
LOW-PASS FILTER
Q104, 110
• SIGNAL PATH
: FM
: MW/LW
D1-1
D6
D7
LIGHT
16
BEEP 52
15
AM/(FM/TV)
56
EO
19
(MW/LW)/SW
4
BPF
3
MUTE
2
AC DET
TUNED
14
VCOL
20
VCOH
25
24
X101
75kHz
XIN
XOUT
17
HOLD
LCD0 – LCD12
21
COM0 – COM3
KEY MATRIX
S101 – 119
35 – 47
31 – 34
KS0 – KS4
1, 6 – 9
KR0 – KR3
10 – 13
LIQUID CRYSTAL DISPLAY
LCD101
(M770L)
CT2, L5-2
LW TRACKING
(M770L)
CT1, L5-1
MW TRACKING
(M770SL)
CT2, L5
LW TRACKING
(M770S)
CT2, L5
MW TRACKING
CT1
Q11, 12
TONE
CONTROL
SWITCH
D1-2
(M770L)
ANT1
FM/SW
ANTENNA
CF4
10.7MHz
3
FM
DISCRIMINATOR
FM
DISCRI
DISCRI
SP1
J201
v
MUTING
SWITCH
SWITCH
Q9
LED DRIVE
Q107
D9
FM/(SW/MW/LW) BAND
SELECT SWITCH
Q10
FM VCO
BUFFER
BUFFER
Q8
FM VCO
BUFFER
BUFFER
Q105
M770S/
M770SL
M770S/
M770SL
SW
SWITCH
Q1
L3
SW
RF
FM/(SW/MW/LW) BAND
SELECT SWITCH
Q5
VCC B+
D2-2
SW
SWITCH
Q4
SW BAND
SELECT SWITCH
Q3
(M770L)
M770S/
M770SL
M770S/
M770SL
S120
HOLD
OFF
+3V B+
HOLD
T202
POWER
TRANSFORMER
RECT
D205, 206
J301
AC IN -
AC DETECT
Q201
AC DETECT
Q103
DRY BATTERY
SIZE "D"
(IEC DESIGNATION R20)
4PCS. 6V
D202 – 204
5
POWER
D201
VCC B+
+3V B+
B+ SWITCH
Q109
+3V
REGULATOR
IC101
DC/DC
CONVERTER
Q106, 111, T101
LOW-PASS
FILTER
CIRCUIT
B+
D102
RV2
TONE
REG OUT
9
REG +1.2V
50
VDET1
51
CEDET
BATTERY
VOLTAGE DETECT
IC102
53
VDET2
BATTERY
VOLTAGE DETECT
IC103
B+ SWITCH
Q101
POWER ON/OFF
CONTROL SWITCH
Q102
FM/(SW/MW/LW) BAND
SELECT SWITCH
Q108
(M770L)
L5-1
MW
FERRITE-ROD
ANTENNA
L5-2
LW
FERRITE-ROD
ANTENNA
REG
+1.2V
REG
+1.2V
REG
+1.2V
Q2
SW
SWITCH
VCC B+
(M770L)
M770S/
M770SL
M770S/
M770SL
M770S/
M770SL
CT1, L3
LW TRACKING
(M770SL)
L10
MW VT
VOLTAGE
(M770S)
L8
SW VT
VOLTAGE
(M770S/M770SL)
L8
MW VT
VOLTAGE
(M770L)
ICF-M770L/M770S/M770SL
9
9
Note on Printed Wiring Board:
•
•
X
: parts extracted from the component side.
•
Y
: parts extracted from the conductor side.
•
W
: indicates side identified with part number.
•
f
: internal component.
•
: Pattern from the side which enables seeing.
(The other layers' patterns are not indicated.)
5-2.
NOTE FOR PRINTED WIRING BOARD AND SCHEMATIC DIAGRAMS
Note on Schematic Diagram:
• All capacitors are in
• All capacitors are in
µ
F unless otherwise noted. pF:
µµ
F
50 WV or less are not indicated except for electrolytics
and tantalums.
and tantalums.
• All resistors are in
Ω
and
1
/
4
W or less unless otherwise
specified.
•
f
: internal component.
•
C
: panel designation.
• IC Block Diagram
IC1
CXA1019S
1
2
3
4
5
6
7
8
9
10
15
14
13
12
11
FM
DISCRIMINATOR
AF POWER AMP
AM FE
FM IF
TUNING
METER
AM IF DET AGC
FM FE
23
22
21
20
24
25
19
18 17 16
29 28 27 26
30
GND
GND
AF OUT
VCC
RIPPLE
FIL
TER
AF IN
DET OUT
AFC AGC
AFC AGC
IF GND
METER
N.C
FM IF IN
AM IF IN
FM/AM BAND
SELECT
FM/AM
IF OUT
FE GND
N.C
AM RF IN
FM RF
REG OUT
FM OSC
FM RF IN
AFC
AM OSC
VOL
NF
FM DISCRI
GND
GND
•
A
: B+ Line.
•
H
: adjustment for repair.
• Power voltage is dc 6 V and fed with regulated dc power
supply from battery terminal.
• Voltages and waveforms are dc with respect to ground in
no-signal (detuned) conditions.
no mark : FM
(
no mark : FM
(
) : SW
[
] : MW
〈〈
〉〉
: LW
• Voltages are taken with a VOM (Input impedance 10 M
Ω
).
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Circled numbers refer to waveforms.
• Signal path.
F
: FM
f
: MW/LW
Note: The components identified by mark
0
or dotted line
with mark
0
are critical for safety.
Replace only with part number specified.
• Circuit Boards Location
jack board
main board
key board
inlet board
power board
ICF-M770L/M770S/M770SL
10
10
A
K/A
K
D5
K
A
K
D9
EC
B
Q12
EC
B
Q11
C55
C63
R30
C45
C57
EC
B
Q10
C38
C37
R28
R29
C34
C43
C52
C32
C58
R19
C28
C27
D7
K
A
C61
R21
C29
R18
C25
C24
D6
K
A
R17
JC7
R22
R27
JC15
R15
R20
C50
C36
C65
EC
B
Q8
Q2
BC
E
R34
C3
R3
R7
EC
B
Q5
D8
A
K
R5
C1
R10
C4
Q1
GD
S
R1
R2
C5
C6
C10
C7
JC14
JC13
C12
C20
1A
K
2A
D1
C15
R11
R13
R12
JC8
JC1
JC3
EC
B
Q4
JC11
C56
R31
C66
C64
JC10
EC
B
Q7
R25
R16
C67
C40
Q9
BC
E
R23
R24
C44
C46
C47
C30
C19
C21
C22
1A
K
2A
D2
R8
R14
C23
C11
C18
EC
B
Q3
R9
JW1
C54
+
1
5
JW2
L6
C48
+
C42
+
C51
+
C41
+
CF1
CF4
C35
+
L14
JW5
JW4
CT4
L13
L12
BPF1
L16
L1
C8
+
C33
+
L15
JW16
L2
JW17
JW12
JW18
CT1
L7
L3
JW15
JW14
JW13
CT2
L10
RV1
JW20
JW19
JW21
L8
L9
L11
JW22
JW6
JW9
JW7
1
15
JW11
JW8
C62
+
JW3
T1
CF3
CF2
IC1
MAIN BOARD
(11)
11
1-684-571-
15
1
16
30
R33
R32
JC5
(M770L)
JC6
(M770L)
R6
EC
B
Q6
C13
C73
(M770L)
(M770L)
(M770S/M770SL)
C59
(M770L)
(M770SL)
M770S/
M770SL
M770S/
M770SL
M770S/
M770SL
VOL
RV2
TONE
JW10
JC4
JC2
C2
C17
C14
C16
(M770L)
CT3
M770S/
M770SL
M770S/
M770SL
(M770L)
A
KEY
BOARD
TP
(VT)
1
2
3
(M770S/M770SL)
TP
(ANT)
ANT1
L5
MW/LW FERRITE-ROD
ANTENNA
A
B
C
D
E
F
G
H
I
1
2
3
4
5
6
7
8
9
10
I
1
4
INLET BOARD
(11)
11
1-684-567-
D201
AK
D202
AK
D203
AK
D204
A
R202
C207
R201
R203
C206
C205
C202
Q201
1
5
C204
+
1
3
D206
D205
C203
+
1
4
J201
JACK BOARD
(11)
11
1-684-568-
T202
POWER
TRANSFORMER
POWER BOARD
(11)
11
1-684-569-
K
v
SP1
DRY BATTERY
SIZE "D"
(IEC DESIGNATION R20)
4PCS. 6V
1
3
J301
~
AC IN
11
12
13
14
15
L5-2
LW FERRITE-ROD
ANTENNA
L5-1
MW FERRITE-ROD
ANTENNA
(M770L)
(M770S/M770SL)
5-3.
PRINTED WIRING BOARDS – MAIN/JACK/POWER/INLET Boards –
•
See page 9 for Circuit Boards Location.
D1
E-3
D2
D-2
D5
C-10
D6
C-5
D7
D-5
D8
B-6
D9
C-9
D201
C-11
D202
C-11
D203
D-11
D204
D-11
D205
D-13
D206
D-13
IC1
D-7
• Semiconductor Location
Ref. No.
Location
Ref. No.
Location
Q1
B-3
Q2
C-4
Q3
C-2
Q4
F-3
Q5
B-4
Q6
D-2
Q7
E-2
Q8
D-5
Q9
G-2
Q10
B-9
Q11
D-9
Q12
C-9
Q201
D-12
(Page 12)
Click on the first or last page to see other ICF-M770L / ICF-M770S / ICF-M770SL service manuals if exist.