Read Sony ICF-S79W Service Manual online
SERVICE MANUAL
Sony Corporation
Audio Business Group
Published by Sony Techno Create Corporation
ICF-S79W
SPECIFICATIONS
WEATHER/FM/AM SYNTHESIZED REDIO
9-889-071-01
2008C05-1
©
2008.03
US Model
Ver. 1.0 2008.03
Frequency range:
Band
ICF-S79W
Channel step
FM
87.5 – 108 MHz
0.1 MHz
AM
530 – 1,710 kHz
10 kHz
WEATHER
1 – 5 ch
—
Time display:
12-hour system
Speaker:
7.7 cm (3
1
/
8
inches), 8 ohms
Power output:
220 mW (at 10% harmonic distortion)
Power requirements:
4.5 V DC, three size C (R14) batteries
Dimensions:Approx. 143.5 x 139 x 67 mm
(w/h/d) (Approx. 5
3
/
4
× 5
1
/
2
× 2
3
/
4
inches) incl. projecting parts and controls
Mass:Approx. 523 g (1lb 2oz) incl. batteries
Supplied accessories: Suction cup (1), Strap (1)
Supplied accessories: Suction cup (1), Strap (1)
Design and specifications are subject to change
without notice.
without notice.
Notes on chip component replacement
•
•
Never reuse a disconnected chip component.
•
Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
aged by heat.
ICF-S79W
2
UNLEADED SOLDER
Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with
Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with
the lead free mark due to their particular size)
: LEAD FREE MARK
Unleaded solder has the following characteristics.
• Unleaded solder melts at a temperature about 40 °C higher
• Unleaded solder melts at a temperature about 40 °C higher
than ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
about 350 °C.
Caution: The printed pattern (copper foil) may peel away if the
about 350 °C.
Caution: The printed pattern (copper foil) may peel away if the
heated tip is applied for too long, so be careful!
• Strong
viscosity
Unleaded solder is more viscous (sticky, less prone to fl ow)
than ordinary solder so use caution not to let solder bridges
occur such as on IC pins, etc.
than ordinary solder so use caution not to let solder bridges
occur such as on IC pins, etc.
• Usable with ordinary solder
It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.
also be added to ordinary solder.
HOW TO CHANGED THE CERAMIC FILTERS
This model is used two ceramic fi lters of CF1 and CF2.
You must used same type of color marked ceramic fi lters in order
to meet same specifi cations.
Therefore, the ceramic fi lter must be changed two pieces together
since it’s supply two pieces in one package as a spare parts.
This model is used two ceramic fi lters of CF1 and CF2.
You must used same type of color marked ceramic fi lters in order
to meet same specifi cations.
Therefore, the ceramic fi lter must be changed two pieces together
since it’s supply two pieces in one package as a spare parts.
Mark
Center frequency
red
10.70 MHz
blue
10.67 MHz
orange
10.73 MHz
black
10.64 MHz
white
10.76 MHz
CF2
mark
CF1
SECTION 1
SERVICING NOTES
SECTION 2
GENERAL
This section is extracted
from instruction manual.
from instruction manual.
1
2
3
4
5
TIMER
SET/ON/OFF
CLOCK
TIME ADJUST
TUNE/TIMER ADJUST
WEATHER
BAND
OFF
RADIO
ON
AUTO OFF
60 45 30 20 10
PRESET TUNING/PRESET TIMER
SELECT/ PRESET
FM wire antenna
Antenne fil FM
Antenne fil FM
VOL
Setting the Clock
“AM 12:00” or “0:00” will flash in the display when the batteries are installed for the first time.
The clock can be adjusted whether or not the radio is on.
The clock can be adjusted whether or not the radio is on.
1
To stop flashing of the display, press
CLOCK.
2
While holding down
CLOCK, press TIME ADJUST + or – until the correct
time appears in the display.
When you release CLOCK, “:” starts to flash and the clock begins to operate.
• The clock system varies depending on the model you own.
12-hour system: “AM 12:00” = midnight, “PM 12:00” = noon.
24-hour system: “0:00” = midnight, “12:00” = noon.
24-hour system: “0:00” = midnight, “12:00” = noon.
• To set the current time rapidly, keep pressing the + or
–button while holding down CLOCK.
• To set the current time from zero seconds, at step 2, release CLOCK with the time signal.
ICF-S79W
3
SECTION 3
DISASSEMBLY
Note: Follow the disassembly procedure in the numerical order shown below.
REAR CABINET BLOCK
Remove the solder
of the BATT lead (red).
Remove the solder
of the BATT lead (white).
BATT lead
(red)
(red)
FM wire antenna
BATT lead
(white)
(white)
two claws
six screws
(BTP3
× 25)
battery case lid
rear cabinet block
Remove the solder
of the FM wire antenna.
ICF-S79W
4
SECTION 4
ELECTRICAL ADJUSTMENTS
[FM/WEATHER Section]
Setting:
BAND button: FM1
WEATHER button: WEATHER
Setting:
BAND button: FM1
WEATHER button: WEATHER
FM RF SSG
± 22.5 kHz frequency
deviation by 400 Hz
signal
Output level: as low as possible
+
–
level meter
speaker terminal
set
FM lead wire antenna terminal
0.01F
[AM Section]
Setting:
BAND button: AM
Setting:
BAND button: AM
AM RF SSG
30% amplitude
modulation by
400 Hz signal
Output level: as low as possible
Put the lead-wire
antenna close to
the set.
+
–
–
level meter
speaker terminal
set
+
–
digital voltmeter
MAIN board
TP (VT)
Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be fi nally
done by the trimmer capacitors.
frequency coverage and tracking adjustments should be fi nally
done by the trimmer capacitors.
0 dB = 1
μV
WB FREQUENCY COVERAGE ADJUSTMENT
Adjust for a reading on digital voltmeter.
L2
WEATHER 2 ch
0.95 ± 0.1 V
Confi rm
WEATHER 1 ch
0.96 ± 0.1 V
Note: Not use the FM RF signal generator in this adjustment.
WB TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L1
WEATHER 2 ch (162.40 MHz)
CT1
WEATHER 1 ch (162.55 MHz)
WB/FM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
L11
10.7 MHz
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a reading on digital voltmeter.
L4
87.5 MHz
6.6 ± 0.1 V
Confi rm
108.0 MHz
12.5 ± 0.5 V
Note: Not use the FM RF signal generator in this adjustment.
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L3
87.5 MHz
CT2
108.0 MHz
AM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a reading on digital voltmeter.
L6
530 kHz
2.8 ± 0.1 V
Confi rm
1,710 kHz
9.7 ± 1.0 V
Note: Not use the AM RF signal generator in this adjustment.
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L5
590 kHz
CT3
1,490 kHz
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T1
455 kHz
Adjustment Location: MAIN board (See page 5)