Sony SRF-M85 Service Manual ▷ View online
SRF-M85
5
2-3. BOARD ASSY
2
Remove two solders.
black
KEY board
1
stopper cushion
red
4
3
claw
7
board assy
MAIN board
6
screw (1.7
×
6)
S101
5
knob (VOL) assy
lever
KEY board
Note: When installing the board assy, adjust S101 and lever.
2-4. SPREADING OF ADHESIVE AGENT
slit
cabinet (rear) assy
adhesive agent
(OK)
(NG)
Note: When installing the cabinet (front) assy,
spread the adhesive agent (TSE3975C 100G)
(Part No.: 7-600-006-17) in the slit.
(Part No.: 7-600-006-17) in the slit.
6
SRF-M85
SECTION 3
ELECTRICAL ADJUSTMENTS
TUNER SECTION
0 dB=1 mV
[AM]
Setting:
BAND button: AM
BAND button: AM
[FM]
Setting:
BAND button: FM
BAND button: FM
•
Repeat the procedures in each adjustment several times, and
the tracking adjustments should be finally done by the trimmer
capacitors.
capacitors.
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
Output level:
as low as possible
modulation by
400 Hz signal
Output level:
as low as possible
Put the lead-wire
antenna close to
the set.
antenna close to
the set.
+
–
–
level meter
set
16
Ω
i
jack (J201)
FM RF signal
generator
75 kHz frequency
deviation by 1 kHz
signal
Output level:
as low as possible
deviation by 1 kHz
signal
Output level:
as low as possible
+
–
–
level meter
0.01
µ
F
MAIN board
TP (RF GND)
TP (RF GND)
MAIN board
TP (ANT IN)
TP (ANT IN)
set
16
Ω
i
jack (J201)
digital voltmeter
TP (VT)
TP (RF GND)
MAIN board
AM VCO VOLTAGE ADJUSTMENT
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
L104
531 kHz
1.3
±
0.05 V
Confirmation
1,710 kHz
7.7
±
0.3 V
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L103
585 kHz
CT101
1,485 kHz
FM FREQUENCY COVERAGE CONFIRMATION
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
Confirmation
108 MHz
8.7
±
0.5 V
Confirmation
87.5 MHz
5.8
±
0.5 V
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L102
87.5 MHz
Adjustment and Connecting Location: MAIN board
(See page 7)
SRF-M85
7
7
SRF-M85
Adjustment and Connecting Location:
AM Tracking Adjustment
CT101
L103
L103
L102
FM Tracking Adjustment
L104
AM VCO voltage Adjustment
TP
(VT)
TP
(ANT IN)
TP
(RF GND)
– MAIN Board (Conductor Side) –
– MAIN Board (Component Side) –
SRF-M85
8
8
SRF-M85
SECTION 4
DIAGRAMS
•
Note for Printed Wiring Boards and Schematic Diagrams
Note on Schematic Diagram:
•
All capacitors are in
µ
F unless otherwise noted. (p: pF)
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.
•
C
: panel designation.
•
A
: B+ Line.
•
H
: adjustment for repair.
•
Power voltage is dc 1.5V and fed with regulated dc power
supply from battery terminal.
no mark : FM
(
supply from battery terminal.
no mark : FM
(
) : AM
•
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.
Voltage variations may be noted due to normal produc-
tion tolerances.
•
Circled numbers refer to waveforms.
•
Signal path.
F
: FM
f
: AM
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.
•
: Pattern from the side which enables seeing.
(The other layers' patterns are not indicated.)
•
Waveforms
– MAIN Board –
1
IC101
wa
(OSCOUT)
100 mV/DIV, 100 ns/DIV
91.5 ns
300 mVp-p
2
IC301
1
(XOUT)
200 mV/DIV, 5
µ
s/DIV
13.3
µ
s
520 mVp-p
3
IC301
ta
(OSCIN)
100 mV/DIV, 50 ns/DIV
91 ns
390 mVp-p
– KEY Board –
KEY BOARD IC301 TC9349FAG-107 (S, D) (SYSTEM CONTROLLER)
Pin No.
Pin Name
I/O
Description
1
XOUT
O
System clock output terminal (75 kHz)
2
VDD
-
Power supply terminal (+1.5V)
3, 4
C1, C2
-
Connection terminal of capacitor for the CPU power supply voltage pressure up
5
VDB
-
Terminal for power supply voltage pressure up
6, 7
C3, C4
-
Connection terminal of capacitor for the liquid crystal display drive power supply voltage pressure up
8
VLCD
O
Voltage (+3V) output terminal for the liquid crystal display drive
9
VEE
O
Constant voltage (+1.5V) output terminal
10
VCPU
-
Power supply terminal for CPU
11, 12
INT1, INT2
I
Destination setting input terminal
13
POWER2
O
Power on/off control signal output for the radio system power supply "L": power on
14
TEST
I
Not used
15 to 18
COM1 to COM4
O
Common drive signal output to the liquid crystal display
19 to 33
S1 to S15
O
Segment drive signal output to the liquid crystal display
34 to 36
KS1 to KS3
O
Key scan signal output for the key matrix
37 to 40
KR1 to KR4
I
Key return signal input for the key matrix
41
INT
I
Voltage detection signal input from the voltage detect "L":Battery no-remainder
42
MEGA BASS
O
MEGA BASS on/off control signal output "H": MEGA BASS on
43
BEEP
O
Beep sound drive signal output terminal
44
POWER1
O
Power on/off control signal output for the radio system power supply "H": power on
45
BAND1
O
FM/AM band selection signal output terminal "L": AM, "H": FM
46
BAND2
O
FM/AM band selection signal output terminal "L": FM, "H": AM
47
MONO/ST
O
Monaural/stereo selection signal output terminal "L": stereo, "H": monaural
48
HOLD
I
HOLD switch detect signal input terminal "H": HOLD on
49
-
-
Not used
50
VPLL
-
Power supply terminal for PLL (+1.5V)
51
OSCIN
I
VCO input from the FM/AM RF amplifier
52
GND
-
Ground terminal for PLL
53
-
-
Not used
54
DO2
O
Phase comparator output terminal
55
-
-
Not used
56
MUTE
O
Muting on/off control signal output terminal "L": muting on
57
DDCK
O
DC/DC converter pressure up clock signal output terminal
58
VDET
I
Pressure up voltage (+1.0V) detection signal input terminal
59
R-ON
O
Division resistor on/off control signal output terminal "L": on
60, 61
-
-
Not used
62
RESET
I
System reset signal input from the reset signal generator "L": reset
For several hundreds msec. after the power supply rises, "L" is input, then it changes to "H"
For several hundreds msec. after the power supply rises, "L" is input, then it changes to "H"
63
GND
-
Ground terminal
64
XIN
I
System clock input terminal (75 kHz)
•
IC Pin Function Description
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