Read Sony ST-SE520 Service Manual online
5
5
SECTION 4
DIAGRAMS
4-1. CIRCUIT BOARDS LOCATION
THIS NOTE IS COMMON FOR PRINTED WIRING
BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed
in each block.)
BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed
in each block.)
For schematic diagrams.
Note:
• All capacitors are in µF unless otherwise noted. pF: µµF
• All capacitors are in µF unless otherwise noted. pF: µµF
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.
•
2
: nonflammable resistor.
•
C
: panel designation.
For printed wiring boards.
Note:
• X
: parts extracted from the component side.
•
x
: parts mounted on the conductor side.
• b
: Pattern from the side which enables seeing.
•
U
: B+ Line.
•
V
: B– Line.
•
H
: adjustment for repair.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : FM
no mark : FM
∗
: Can not be measured.
WAVEFORMS
1
IC802
qf
Note: The components identified by mark
0
or dotted line
with mark
0
are critical for safety.
Replace only with part number specified.
• Indication of transistor
• 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.
• Signal path.
F
: FM
SECTION 3
ELECTRICAL ADJUSTMENTS
FM Signal Level Adjustment
Adjustment Location:
[TUNER BOARD] — Component Side —
Procedure:
1. Tune the set to 98 MHz.
2. Push the DISPLAY button for digital signal meter indication.
3. Adjust RV201 to the place where level and “70dB
1. Tune the set to 98 MHz.
2. Push the DISPLAY button for digital signal meter indication.
3. Adjust RV201 to the place where level and “70dB
M” indica-
tion lights on fluorescent indicator tube.
2
IC701
qs
FM RF signal
generator
generator
set
FM ANTENNA
75
75
Ω
coaxial
(TB101)
Carrier frequency : 98 MHz
Modulation
Modulation
: 1 kHz, 40 kHz deviation
Output level
: 6.3 mV (76dB
µ
)
(75
Ω
open)
IC201
RV201
FM SIGNAL LEVEL
FM SIGNAL LEVEL
AC SW board
ENCODER board
TRANSFORMER board
DISPLAY board
TUNER board
C
These are omitted
E
B
4.8Vp-p
4.332MHz
4.3Vp-p
4.19MHz
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