Sony tc w 190 service manual

Page 2

TC-W1 90/W300 i

SAFETY CH ECK-OUT -MODEL IDENTIFICATION-
(Specification Label)
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 TC-W190:

knobs, screws, and all other exposed metal parts for

AC leakage. Check leakage as described below. S ONYO MODEL NO TC-W190
LEAKAGE TEST STEREO CASSETTE DECK

The AC leakage from any eXposed metal part to ACIZOV 60: 15

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-S40A. Follow the
manufacturers instructions to use these instru-
ments.

. TC-WBOO:
2. A batterycperated AC mIlliammeter. The Data

Precision 245 digital multimeter is suitable for

this job. SONYw MODEL NO. TC-W300
i

3. Measuring the voltage drop across a resistor by
means of a VOM or battery-Operated AC volt- STEREO CASSETTE DECK
meter. 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 passive VOM that
is suitable. Nearly all battery operated digital
multimeters that have a 2V AC range are
suitable. (See Fig. A)

Ta Exposed Metal
Parts on Set

US, Canadian model: ACIZOV 60Hz 15W
AEP model: A0220V~50/60Hz 15W
UK model: A0240V~50/60Hz 15W
E model: A0120, 220,240V~50/60Hz 15W

.1: AC
0.15uF éijka / voltmeter
(0.75 VI

"7" Earth Ground

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

SAFETY-RELATED COMPONENT WARNINcu ATTENTION AUCOMPQSANT AYANT RAPPORT

COMPONENTs IDENTIFIED 3v MARK A OR DOTTED A LA SECER'TE'

LINE WITH MARK A ON THE SCHEMATIC DIAGRAMS LES COMPOSANTS IDENTIFIES PAR UNE MAROUE A
AND IN THE PARTS LIST ARE CRITICAL TO SAFE SUR LES DIAGRAMMES SCHEMATICIUES ET LIA LISTE
OPERATION. REPLACE THESE COMPONENTS WITH DES PIECES SONT CRITIQUES POUR LA SECURITE
SONY PARTS WHOSE PART NUMBERS APPEAR AS DE FONCTIONNEMENT. NEREMPLACER CEs COM-
SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUB- POSANTS OUE PAR DES PIECES SONY DONT LES
LISHED BY SONY. . NUMEROS SONT DONNES DANS CE MANUEL OU

DANS LES SUPPLEMENTS PUBLIES PAR SONY.