Sony WE475 Service Manual - Page 2

A battery-operated AC milliammeter. The Data Precision 245 - tc

Page 2 highlights

TC-WE475 General Power requirements U.S.A.and Canadian models: 120 V AC, 60Hz European models: 230 V AC, 50/60Hz Australian models: 240 V AC, 50/60Hz Other models: 120/220/230-240 V AC, 50/60Hz Adjustable with voltage selector Power consumption 18 watts Dimensions (w/h/d) Approx. 430 × 120 × 300 mm Mass 4.2 kg Supplied accessories Audio connecting cords (2) Control A1II cable (1)* *Supplied for Canadian models only Design and specifications are subject to change without notice. SAFETY CHECK-OUT After correcting the original service problem, perform the following safety checks 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 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 a VOM 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 passive VOM that is suitable. Nearly all battery operated digital multimeters that have a 2V AC range are suitable. (See Fig. A) To Exposed Metal Parts on Set 0.15µF 1.5kΩ AC voltmeter (0.75V) Earth Ground Fig. A. Using an AC voltmeter to check AC leakage. SAFETY-RELATED COMPONENT WARNING!! COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED LINE WITH MARK 0 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 MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY. 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 COMPOSANTS QUE PAR DES PIÈCES SONY DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU DANS LES SUPPLÉMENTS PUBLIÉS PAR SONY. 2

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2
TC-WE475
SAFETY-RELATED
COMPONENT
WARNING!!
COMPONENTS
IDENTIFIED
BY
MARK
0
OR
DOTTED
LINE
WITH
MARK
0
ON
THE
SCHEMATIC
DIAGRAMS
AND
IN
THE
PARTS
LIST
ARE
CRITICAL
TO
SAFE
OPERATION.
RE-
PLACE
THESE
COMPONENTS
WITH
SONY
PARTS
WHOSE
PART
NUMBERS
APPEAR
AS
SHOWN
IN
THIS
MANUAL
OR
IN
SUPPLEMENTS
PUBLISHED
BY
SONY.
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 COMPOSANTS QUE PAR DES PIÈCES SONY
DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU
DANS LES SUPPLÉMENTS PUBLIÉS PAR SONY.
SAFETY
CHECK-OUT
After correcting the original service problem, perform the follow-
ing safety checks 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
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 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 a VOM
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 pas-
sive VOM 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.
0.15
µ
F
To Exposed Metal
Parts on Set
1.5k
AC
voltmeter
(0.75V)
Earth Ground
General
Power requirements
U.S.A.and Canadian models:
120 V AC, 60Hz
European models:
230 V AC, 50/60Hz
Australian models:
240 V AC, 50/60Hz
Other models:
120/220/230-240 V AC, 50/60Hz
Adjustable with voltage selector
Power consumption
18 watts
Dimensions (w/h/d)
Approx. 430
×
120
×
300 mm
Mass
4.2 kg
Supplied accessories
Audio connecting cords (2)
Control A1II cable (1)*
*Supplied for Canadian models only
Design and specifications are subject to change
without notice.