Sony Icf-c135 User manual

ICF-C135

US Model

Canadian Model

SERVICE MANUAL

FM/AM CLOCK RADIO

MICROFILM

SPECIFICATIONS FEATURES

Ver 1.0 1999.10

— 2 —

ATTENTION AU COMPOSANT AYANT RAPPORT

À LA SÉCURITÉ!

LES COMPOSANTS IDENTIFIÉS PAR UNE MARQUE 0

SUR LES DIAGRAMMES SCHÉMATIQUES ET LA LISTE

DES PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ

DE FONCTIONNEMENT. NE REMPLACER CES COM-

POSANTS 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 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

PUBLISHED BY SONY.

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 forAC 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. 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 aVOM

or battery-operated AC voltmeter. The “limit” indication is

0.75 V, so analog meters must have an accurate low-voltage

scale. The Simpson 250 and Sanwa SH-63Trd are examples of a

passiveVOM that is suitable. Nearly all battery operated digital

multimeters that have a 2V AC range are suitable. (See Fig.A)

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

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.

SECTION 1

SERVICING NOTES

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.

CF1

mark 2

CF3

mark 2

mark 1

CORD DRESSING

(POWER, ANTENNA, BATTERY)

1) Connect the power cord, antenna cord, and battery cord as

shown in the figure.

2) Mount the chassis with screws (PTP3 ×10).

Note: Tighten completely the screws (PTP3 ×10).

1.5 k

Ω

0.15

FAC

voltmete

(0.75 V)

To Exposed Metal

Parts on Set

Earth Ground

battery cord

screw (PTP3

10)

antenna cord

power cord

chassis

Mark 1 Mark 2 Center

frequency

red — 10.70MHz

blue — 10.67MHz

orange — 10.73MHz

black — 10.64MHz

white — 10.76MHz

white white 10.75 MHz

yellow — 10.79 MHz

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SECTION 2

GENERAL This section is extracted from

instruction manual.

— 4 —

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

SECTION 3

DIAL POINTER SETTING

pointer

As shown in figure,

marking

of TUNE

knob and marking

of VOL knob setting.

screw

(P3

10)

RADIO board

Set the pointer to

the guide line.

chassis

Turn CV1 and RV1 shaft in

the arrow direction fully.

speaker

pointer guide line

knob (TUNE)

knob (VOL)

marking

CV1

RV1

RADIO board

(Conductor Side)

marking

SECTION 4

ELECTRICAL ADJUSTMENTS

[FM]

Setting:

BAND switch: FM

[AM]

Setting:

BAND switch: AM

Repeat the procedures in each adjustment several times, and the

frequency coverage and tracking adjustments should be finally done

by the trimmer capacitors.

FM FREQUENCY COVERAGE ADJUSTMENT