Read Sony ICF-903L Service Manual online
– 1 –
SERVICE MANUAL
AEP Model
UK Model
ICF-903L
FM/SW/MW/LW 4 BAND RADIO
(Photo: BLACK)
Frequency range:
Band
FM
87.5 - 108.0 MHz
SW
5.95 - 18 MHz
MW
530 - 1605 kHz
LW
153 - 255 kHz
Speaker:
Approx. 10.2 cm (4
1/8
inches) dia. 8
Ω
Power output:
430 mW (at 10 % harmonic distortion)
Output:
v
jack (ø 3.5 mm minijack)
Power requirements:
With the supplied AC power cord:
220 - 230 V AC, 50 Hz
With four R6 (size AA) batteries: 6V DC
Dimensions:
Approx. 265
×
137
×
69 mm (w/h/d)
(10
1/2
×
5
1/2
×
2
3/4
inches) incl. projecting parts
and control with carrying handle pushed in.
Mass:
Approx. 1081 g (2 lb 6 oz) incl. batteries
Supplied accessory:
AC power cord (1)
Design and specifications are subject to change without
notice.
notice.
SPECIFICATIONS
Ver 1.0 2000. 04
– 2 –
mark
mark
• white/white only
CF2
CF3
CF3
CF4
mark
mark
CF3
CF2
CF4
mark
Center
Frequency
Frequency
red
10.70 MHz
blue
10.67 MHz
orange
10.73 MHz
black
10.64 MHz
white
10.76 MHz
white/white
10.75 MHz
yellow
10.79 MHz
HOW TO CHANGE THE CERAMIC FILTERS
This model is used two ceramic filters of CF2, CF3 and CF4.
You must use same type of color marked ceramic filters in order to
meet same specifications.
Therefore, the ceramic filter must change two pieces together since
it’s supply two pieces in one package as a spare parts.
You must use same type of color marked ceramic filters in order to
meet same specifications.
Therefore, the ceramic filter must change two pieces together since
it’s supply two pieces in one package as a spare parts.
Notes on Chip Component Replacement
•
Never reuse a disconnected chip component.
•
Notice that the minus side of a tantalum capacitor may be
damaged by heat.
damaged by heat.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK
0
OR DOTTED LINE
WITH MARK
0
ON THE SCHEMATIC DIAGRAMS AND IN
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE
PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR
IN SUPPLEMENTS PUBLISHED BY SONY.
REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE
PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR
IN SUPPLEMENTS PUBLISHED BY SONY.
TABLE OF CONTENTS
1. GENERAL
Choosing Power Sources .............................................................. 3
Operating the Radio Manual Tuning ............................................ 3
Operating the Radio Manual Tuning ............................................ 3
2. DISASSEMBLY
2-1. Cabinet (Rear) ..................................................................... 4
2-2. Power Board ........................................................................ 4
2-3. Main Board, Key Board ...................................................... 5
2-4. Setting the Pointer ............................................................... 5
2-2. Power Board ........................................................................ 4
2-3. Main Board, Key Board ...................................................... 5
2-4. Setting the Pointer ............................................................... 5
3. ELECTRICAL ADJUSTMENTS
3-1. MW section ......................................................................... 6
3-2. LW section .......................................................................... 6
3-3. SW section .......................................................................... 7
3-4. FM section ........................................................................... 7
3-2. LW section .......................................................................... 6
3-3. SW section .......................................................................... 7
3-4. FM section ........................................................................... 7
4. DIAGRAMS
4-1. Block Diagram .................................................................... 9
4-2. Printed Wiring Boards (1/2) .............................................. 11
4-3. Printed Wiring Board (2/2) ................................................ 13
4-4. Schematic Diagrams .......................................................... 15
4-2. Printed Wiring Boards (1/2) .............................................. 11
4-3. Printed Wiring Board (2/2) ................................................ 13
4-4. Schematic Diagrams .......................................................... 15
5. EXPLODED VIEWS
5-1. Cabinet (Front) Section ..................................................... 17
5-2. Cabinet (Rear) Section ...................................................... 18
5-2. Cabinet (Rear) Section ...................................................... 18
6. ELECTRICAL PARTS LIST
....................................
19
– 3 –
SECTION 1
GENERAL
This section is extracted
from instruction manual.
from instruction manual.
– 4 –
1
BTP 3x10
5
button (power)
4
Removal the solders.
CN401
WHT
/BLK
/BLK
WHT/BLK
BLK
6
POWER board
3
CN401
2
lid, battery case
3
BTP 3x16
2
BTP 3x16
4
BTP 3x16
6
1
5
cabinet (rear)
Note : This set can be disassemble according to the following sequence.
Note : Follow the disassembly procedure in the numerical order given.
2-1. CABINET (REAR)
2-2. POWER BOARD
SECTION 2
DISASSEMBLY
Set
Cabinet (Rear)
Power Board
Main Board, Key Board
Setting the Pointer