Sony Dream Machine ICF-C490 User manual

SERVICE MANUAL

FM/AM CLOCK RADIO

E Model

Australian Model

SPECIFICATIONS

ICF-C490

Ver 1.1 2002.07

9-873-921-02 Sony Corporation

2002G0500-1 Personal Audio Company

C2002.07 Published by Sony Engineering Corporation

Time display

Australia: 12-hour system

Other countries: 24-hour system

Frequency range

FM: 87.5-108 MHz

AM: 530-1 710 kHz

Speaker

Approx. 6.6 cm ( 2 5/8inches) dia. 8 Ω

Power output

120 mW (at 10 % harmonic distortion)

Power requirements

Australia: 240 V AC, 50 Hz

Other countries: 220-230 V AC, 50 Hz

For power backup: 9 V DC, one 6F22 battery

Battery life

Approx. 20 hours (for clock backup) using Sony

006P (6F22) battery

Dimensions

Approx. 200 ×94 ×113 mm (w/h/d)

(7 7/8×3 3/4×4 1/2inches) not incl. projecting parts and

controls

Mass

Approx. 645 g (1 lb 6.75 oz) not incl. battery

Design and specifications are subject to change

without notice.

ICF-C490

TABLE OF CONTENTS

1. GENERAL .................................................................. 3

2. DISASSEMBLY

2-1. Disassembly Flow ........................................................... 4

2-2. Cabinet (Upper) Assy...................................................... 4

2-3. MAIN Board ................................................................... 5

3. ELECTRICAL ADJUSTMENTS........................ 6

4. DIAGRAMS

4-1. Block Diagram ............................................................... 8

4-2. Note for Printed Wiring Boards and

Schematic Diagram ......................................................... 9

4-3. Printed Wiring Boards.................................................... 10

4-4. Schematic Diagram ........................................................ 11

5. EXPLODED VIEWS

5-1. Cabinet Section ............................................................... 12

5-2. Chassis Section ............................................................... 12

6. ELECTRICAL PARTS LIST .............................. 13

SAFETY-RELATED COMPONENT WARNING!!

COMPONENTS IDENTIFIED BY MARK 0OR DOTTED

LINE WITH MARK 0ON 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 PUB-

LISHED BY SONY.

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.

ICF-C490

SECTION 1

GENERAL This section is extracted from

instruction manual.

SNOOZE

BUZZER

TIME SET

RADIO

ALARM

RESET

HOLD

RADIO BUZZERCLOCK OFF

RADIO BUZZERRADIO+BUZZER

ALARM MODEALARM TIME/CLOCK SET

BUZZER VOLUME BRIGHTNESS

LOW HIGH

FAST SLEEPFAST RADIO

RADIO

OFF

BAND

VOL TUNING

AM FM

AC power cord

Cordon d’alimentation

secteur

Netzkabel

FM wire antenna

Fil d’antenne FM

UKW-Wurfantenne

Indicator

Indicateurs

Stand

Support

Ständer

There is a tactile dot beside volume to show the

direction to turn up the volume.

Un point tactile, situé à côté de la molette de volume,

indique le sens dans lequel il faut tourner pour

augmenter le volume.

Neben dem Lautstärkeregler befindet sich ein

fühlbarer Punkt. Dieser gibt die Richtung an, in der

man die Lautstärke erhöht.

Setting the Clock

To control the visibility of the display, set

BRIGHTNESS for the display to HIGH or LOW

according to your preference.

Plug in the clock radio.

The display will flash “AM 12:00” or “0:00”.

Set the

ALARM TIME/CLOCK SET

switch to

CLOCK

3Press

FAST+

FAST–

to adjust the

time.

When you press FAST+, the time is raised

rapidly.

When you press FAST–, the time is lowered

rapidly.

When you press +, the time is raised in one-

minute steps.

Set the

ALARM TIME/CLOCK SET

switch to

HOLD

Make sure that the ALARM TIME/CLOCK SET

switch is set to HOLD. When it is set to HOLD,

you cannot see the red label underneath.

Otherwise, the displayed time might be

changed if FAST+, FAST– or +happens to be

pressed.

The clock system varies depending on the model

you own.

12-hour system: “AM 12:00”=midnight

24-hour system: “0:00”=midnight

To display minute and second, press SNOOZE.

Example: When the current time is 7:15:10, the

display will become:

7:15 , 5:10

Lower of minute digit Second digits

The display returns to the current time when you

release SNOOZE.

To adjust the time exactly to the second, press +

briefly with the time signal.

ICF-C490

• This set can be disassembled in the order shown below.

2-1. DISASSEMBLY FLOW

SECTION 2

DISASSEMBLY

Note: Follow the disassembly procedure in the numerical order given.

2-2. CABINET (UPPER) ASSY

screw (P3

14)

S101

cap (R)

screw (P3

30)

screw (P3

30)

cap (L)

screw (P3

30)

S102

cabinet (upper) ass

knob (alarm)

knob (clock)

Note :When installing

cabinet (upper) assy,

adjust S102, S101 and

the knobs (clock, alarm).

SET

2-2. CABINET (UPPER) ASSY

(page 4)

2-3. MAIN BOARD

(page 5)

ICF-C490

2-3. MAIN BOARD

•MAIN BOARD SETTING

knob (band)

claw

screw (P3

14)

main board

speker (6.6 cm) (SP1)

LED board

washer

two screws

(P3

14)

screw

(PTPWH3

power cord (PC1)

power board

washer

antenna (wire) (W7

)

knob (vol)

knob (tuning

)

RV1

shaft of CV1

Note 1 : When installing the main board,

adjust RV1 and the knob (vol).

Note 2 : When installing the main board,

turn the shaft of CV1 in the direction

of arrow

fully and the knob (tuning)

in the direction of arrow

fully

before adjusting the shaft of CV1

and the knob (tuning).

ICF-C490

0 dB = 1 µV

[AM]

Setting:

BAND switch: AM

[FM]

Setting:

BAND switch: FM

•Repeat the procedures in each adjustment several times, and the

frequency coverage and tracking adjustments should be finally

done by the trimmer capacitors.

•Remove FM antenna in FM adjustments.

Adjustment Location: MAIN board (See page 7)

FM RF signal

generator

22.5 kHz frequency

deviation by 400 Hz

signal

Output level: as low as possible

–

level mete

MAIN board

TP (SP –)

MAIN board

TP (SP +)

set

MAIN board

TP (FM ANT)

8 Ω

0.01 µF

AM IF ADJUSTMENT