Ver 1.1
MICROFILM
ICF-C723/C723L
SERVICE MANUAL
ICF-C723
FM/AM PLL SYNTHESIZED CLOCK RADIO
ICF-C723L
FM/MW/LW PLL SYNTHESIZED CLOCK RADIO
SPECIFICATIONS
US Model
Canadian Model
E Model
Australian Model
ICF-C723
UK Model
ICF-C723L
AEP Model
ICF-C723/C723L
Radio section
Frequency range :
US, Canadian model
Band
ICF-C723
Channel step
FM
87.5 108 MHz
0.1MHz
AM
530 1,710 kHz
10kHz
EXCEPT US, Canadian model
Band
ICF-C723
ICF-C723L
Channel step
FM
87.5 108 MHz
87.5 108 MHz
0.05MHz*
AM (MW) 531 1,602 kHz
530 1,602 kHz
9kHz
LW
530 1,602 kHz
9kHz
* The frequency display is raised or lowerd by steps of
0.1MHz.
(Example : Frequency 88.05 MHz is displayed as "88.0
MHz".)
DIGITAL VOICE MEMO Recording section
Recording media
Built-in flash memory
Recording time
20 seconds
Frequecy response
400Hz 2,700Hz
General
Time display
US, Canadian, UK model
12-hour
EXCEPT US, Canadian, UK model
24-hour
Speaker
Approx. 5.7 cm (2 1/4 in) dia.
Power output
100 mW (at 10% harmonic distortion)
Power requirements
US, Canadian model :120V AC, 60Hz
EXCEPT US, Canadian model : 220 230V AC, 50Hz
Dimensions
Approx. 181 x 103 x 133 mm (w/h/d)
(7 1/4 x 4 1/8 x 4 1/4 in) incl. projecting parts and controls
Mass
Approx. 550 g (1 lb 3.4 oz)
Approx. 600 g (1 lb 5.2 oz) : ICF-C723L (UK model)
Design and specifications are subject to change without notice.
2
TABLE OF CONTENTS
Specifications ........................................................................... 1
1. GENERAL
Location and Function of Controls .................................... 3
2. DISASSEMBLY
2-1. Cabinet (Upper) Removal ........................................... 4
2-2. Microcomputer Board Removal ................................. 4
2-3. Main Board, Key Board, Transformer (Primary)
Board, Transformer (Secondary) Board Removal ...... 5
Installation Power Cord ..................................................... 5
3. ELECTRICAL ADJUSTMENT ................................ 6
4. DIAGRAMS
4-1. Explanation of IC Terminal ........................................ 8
4-2. Printed Wiring Board (Microcomputer Section) ........ 9
4-3. Schematic Diagram ((Microcomputer Section) ......... 11
4-4. Printed Wiring Board (Main Section) ....................... 13
4-5. Schematic Diagram (Main Section) ......................... 15
5. EXPLODED VIEW ..................................................... 18
6. ELECTRICAL PARTS LIST ................................... 19
MODEL NO.
MODEL IDENTIFICATION
Model Number Portion
Carved on lower cabinet
ICF-C723
ICF-C723L
US, Canadian model : AC : 120V
/60Hz 5W
AEP, UK, Italian,
E, Australian model
: AC : 220 230V
/50Hz 5W
SAFETY CHECK-OUT
After correcting the original service problem, perform the
following safety check before releasing the set to the customer :
Check the antenna terminals, metal trim, "metallized" knobs,
screws, and all other exposed metal parts for AC leakage. Check
leakage as described below.
LEAKAGE TEST
The AC leakage from any exposed metal part to earth ground
and from all exposed metal parts to any exposed metal part
having a return to chassis, must not exceed 0.5mA (500
microampers).
Leakage current can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or
RCA WT-540A. Follow the manufacturers' instructions to
use these instruments.
2. A battery-operated AC milliammeter. The Data Precision 245
digital multimeter is suitable for this job.
3. Measuring the voltage drop across a resistor by means of a
VOM or battery-operated AC voltmeter. The "limit" indica-
tion is 0.75V, so analog meters must have an accurate low-
voltage scale. The Simpson 250 and Sanwa SH-63Trd are
examples of a passive VOM that is suitable. Nearly all
battery operated digital multimeters that have a 2V AC range
are suitable. (See Fig. A)
AC
voltmeter
(0.75V)
To Exposed Metal
Parts on Set
Earth Ground
0.15
µF
1.5k
Fig. A. Using an AC voltmeter to check AC leakage.
ATTENTION AU COMPOSANT AYANT RAPPORT
À LA SÉCURITÉ!
LES COMPOSANTS IDENTIFIÉS PAR UNE MARQUE
! SUR LES
DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES PIÈCES SONT
CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT. NE
REMPLACER CES COMPOSANTS QUE PAR DES PIÈCES SONY
DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU
DANS LES SUPPLÉMENTS PUBLIÉS PAR SONY.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK
! OR DOTTED LINE WITH
MARK
! 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.
·
HOW TO CHANGE THE CERAMIC FILTER
This model is used two ceramic filters of CF1 and CF3.
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 package as a spare parts.
mark
mark
CF1
CF3
red
10.70MHz
blue
10.67MHz
orange
10.73MHz
black
10.64MHz
white
10.76MHz
Mark
Center
frequency
3
SECTION 1
GENERAL
*
* ICF-C723
: FM, AM
ICF-C723L : FM, MW, LW
LOCATION AND FUNCTION OF CONTROLS
4
SECTION 2
DISASSEMBLY
Note : Follow the disassembly procedure in the numerical order given.
2-1. CABINET (UPPER) REMOVAL
2-2. MICROCOMPUTER BOARD REMOVAL
Precision driver
1 Screws +P (3x14)
Claw
2
3
4
Cabinet (Upper)
Cabinet (lower)
3 Claws
1 CN101
2 CN102
4
5
Holder (transformer)
Cabinet (lower)
Microcomputer board
5
INSTALLATION POWER CORD
2-3. MAIN BOARD, KEY BOARD, TRANSFORMER (PRIMARY) BOARD,
TRANSFORMER (SECONDARY) BOARD, REMOVAL
6 Claw
6 Claw
4 Claw
8 Transformer (primary) board
9 Transformer (secondary) board
4 Claw
4 Claw
1 Screws +P (3x14)
3 CN1
2
5
7
Power transformer (T201)
Shield case (transformer)
Main board
Cabinet (lower)
Key board
power cord
power cord
Cabinet (lower)
Cabinet (lower)
US model
EXCEPT US model