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MODEL IDENTIFICATIONÐ BACK PANEL Ð
MODEL PARTS No.
DA555ES:US model 4-219-066-0¹
DA555ES:Canadian model 4-219-066-1¹
DA333ES:US model 4-219-066-2¹
DA333ES:Canadian model 4-219-066-3¹
PA R T N O .
After correcting the original service problem, perform the fol-
lowing safety checks before releasing the set to the customer:
Check the antenna terminals, metal trim, ÒmetallizedÓ knobs, screws,
and all other exposed metal parts for AC leakage. Check leakage as
described below.
LEAKAGE
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). Leak-
age 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 manufacturersÕ 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 ÒlimitÓ 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 pas-
sive VOM that is suitable. Nearly all battery operated digital
multimeters that have a 2V AC range are suitable. (See Fig. A)
SAFETY CHECK-OUT
To Exposed Metal
Parts on Set
0.15
µF
1.5 k ½
AC
Voltmeter
(0.75 V)
Earth Ground
Fig. A. Using an AC voltmeter to check AC leakage.
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 AP-
PEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUB-
LISHED BY SONY.ATTENTION AU COMPOSANT AYANT RAPPORT
Ë LA SƒCURITƒ!
LES COMPOSANTS IDENTIFƒS PAR UNE MARQUE ! SUR LES
DIAGRAMMES SCHƒMATIQUES ET LA LISTE DES PIéCES SONT
CRITIQUES POUR LA SƒCURITƒ DE FONCTIONNEMENT. NE
REMPLACER CES COMPOSANTS QUE PAR DES PIéSES SONY
DONT LES NUMƒROS SONT DONNƒS DANS CE MANUEL OU
DANS LES SUPPƒMENTS PUBLIƒS PAR SONY.
