Sony ICFC-121 Service manual

ICF-C121

SERVICE MANUAL

SPECIFICATIONS

US Model

Canadian Model

E Model

FEATURES

MICROFILM

FM/AM CLOCK RADIO

SECTION 1

SERVICING NOTES

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 0.5 mA (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. Follo w the manufacturers’ instructions to use these
instruments.

2. A battery-operated AC milliammeter. T he 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” indica­tion is 0.75 V, so analog meters must have an accurate low­voltage 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 2 V AC range are suit­able. (See Fig. A)

To Exposed Metal
Parts on Set

HOW TO CHANGE THE FM CERAMIC FILTERS

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 one package as a spare parts.

Center

frequency

mark 1

mark 2

CF1

mark 2

Mark 1 Mark 2

CF3

red — 10.70MHz

blue — 10.67MHz

orange — 10.73MHz

black — 10.64MHz
white — 10.76MHz
white white 10.75 MHz

yellow — 10.79 MHz

CORD DRESSING
(POWER, ANTENNA, BATTERY)

1) Connect the power cord, antenna cord, and battery cor d as
shown in the figure.

2) Mount the chassis with screws (PTP3 × 10).
Note: Tighten completely the screws (PTP3 × 10).

AC

1.5 k

0.15 µF

Fig. A. Using an AC voltmeter to check AC leakage.

Ω

Earth Ground

voltmeter
(0.75 V)

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.

screw (PTP3

×

battery cord

antenna cord

power cord

chassis

10)

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 MANU AL OR IN SUPPLEMENTS PUB­LISHED BY SONY.

ATTENTION AU COMPOSANT AYANT RAPPORT

À LA SÉCURITÉ!

LES COMPOSANTS IDENTIFIÉS P AR 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.

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SECTION 2

GENERAL

This section is extracted from
instruction manual.

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