Read Sony STR-V220 Service Manual online
STR-V220
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.
•
¢
: internal component.
•
2
: nonflammable resistor.
•
C
: panel designation.
For printed wiring boards.
Note:
• X
: parts extracted from the component side.
• b
: Pattern of the conductor side.
•
U
: B+ Line.
•
V
: B– Line.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : FM
no mark : FM
WAVEFORMS
1
2
IC201
#¢
X1
IC301
#™
Note: The components identified by mark
!
or dotted line
with mark
!
are critical for safety.
Replace only with part number specified.
• Indication of transistor
C
These are omitted
E
B
8MHz
4.8Vp-p
4.19MHz
5.4Vp-p
Caution:
Pattern face side:
Pattern face side:
Parts on the pattern face side seen from
(Conductor Side)
the pattern face are indicated.
Parts face side:
Parts on the parts face side seen from
(Component Side)
the parts face are indicated.
• 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
SECONDARY board
PRIMARY board
STANDBY board
MAIN board
VOL-TONE board
DISPLAY board
PHONE JACK board
KEY board
MAIN (1/3) SECTION
DISPLAY SECTION
– 5 –
– 6 –
SECTION 3
ELECTRICAL BLOCK CHECKING
ADJUSTING THE FM/SD SIGNAL SENSITIVITY
Setting:
oscilloscope
Main board
TP (IC501
6
pin)
Procedure:
1. Set the SSG output level to 26 dB and input the signal.
2. Adjust SFR501 so that the oscilloscope level becomes 0V.
3. Raise the SSG output level slightly (max. 35 dB) when the ad-
1. Set the SSG output level to 26 dB and input the signal.
2. Adjust SFR501 so that the oscilloscope level becomes 0V.
3. Raise the SSG output level slightly (max. 35 dB) when the ad-
justment in step 2 fails, and repeat steps 1 and 2.
NOTE: If the adjustment cannot be performed even when set to 35
dB, the sensitivity may be faulty, etc. Check the antenna
terminal connection, FM front end and IF circuit, etc. and
perform adjustments again.
terminal connection, FM front end and IF circuit, etc. and
perform adjustments again.
FM ANTENNA (75
Ω
)
FM RF SSG
Set
Carrier frequency: 98 MHz
Modulation:
Modulation:
AUDIO 1 kHz,
75 kHz deviation (100%)
75 kHz deviation (100%)
Output level:
26 dB (at 75
Ω
open) (MAX 35 dB)
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