Sony ICFC-253 Service manual
ICF-C253
SERVICE MANUAL
Ver 1.0 2000. 04
SPECIFICATIONS
Australian Model
FM/AM PLL SYNTHESIZED CLOCK RADIO
SECTION 1
GENERAL
This section is extracted
from instruction manual.
SAFETY CHECK-OUT
After correcting the original service problem, perform the following
safety checks before releasing the set to the customer.
1. Check the area of your repair for unsoldered or poorly-soldered
connections. Check the entire board surface for solder splashes
and bridges.
2. Check the interboard wiring to ensure that no wires are
"pinched" or contact high-wattage resistors.
3. Look for unauthorized replacement parts, particularly
transistors, that were installed during a previous repair . Point
them out to the customer and recommend their replacement.
4. Look for parts which, through functioning, show obvious signs
of deterioration. Point them out to the customer and
recommend their replacement.
5. Check the B+ voltage to see it is at the values specified.
6. Flexible Circuit Board Repairing
• Keep the temperature of the soldering iron around 270˚C
during repairing.
• Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
• Be careful not to apply force on the conductor when soldering
or unsoldering.
— 2 —
SECTION 2
d
DISASSEMBLY
• The equipment can be removed using the following procedure.
Cabinet (upper) Set
Key board
Main board
Power boar
Note : Follow the disassembly procedure in the numerical order given.
2-1. CABINET (UPPER)
1
Five screws (M3
× 14)
2
Cabinet (upper)
3
Remove the two solderings.
4
Speaker
1
— 3 —
2-2. KEY BOARD
s
1
Two claws
5
Two claws
3
Remove the eight solderings.
4
Key board
2
Two claws
6
Chassi
2-3. MAIN BOARD
6
LED board
7
Cabinet (lower)
5
Remove the four solderings.
2
Two screws (BTP 2
× 8)
3
Alarm dial board
1
Remove the
five solderings.
7
Remove the four solderings.
8
Main board
— 4 —
4
Claw
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