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AC-V60A/V65A
SAFETY
CHECK-OUT
After correcting the original service problem, perform the following
safety checks before releasing the set to the customer:
1.
Check the area of your repair for unsoldered or
poorly-soldered
connections.
Check the entire
board surface for solder splashes and bridges.
oD
Check the interboard
wiring to ensure that no
wires
are
"pinched"
or contact
high-wattage
resistors.
:
|
3.
Look for unauthorized replacement parts, par-
ticularly transistors, that were installed during.a
previous repair. Point them out to the customer
and recommend
their replacement. |
which, though functioning, show
4.
Look for parts
obvious signs of deterioration.
Point them out
to the customer and recommend
their replace-
ment.
$.
Check
the
line
cord
for
cracks
and
abrasion.
Recommend
the replacement
of any such line
cord
to the customer.
6.
Check
the B+ voltage to see it is at the values
specified.
7.
Check
the
antenna
terminals,
"metallized'""
knobs,
screws,
and
all
exposed
metal
parts for AC
leakage.
leakage as described below.
metal
trim,
other
Check
To Exposed Metal
Parts on Set
AC
voltmeter
{0.75 V)
Earth Ground
Fig. A.
Using an AC voltmeter to check AC leakage.
SAFETY-RELATED
COMPONENT
WARNING!!
COMPONENTS IDENTIFIED BY SHADING AND MARK
ON
THE
SCHEMATIC
DIAGRAMS,
EXPLODED
VIEWS 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.
CIRCUIT
ADJUSTMENTS
THAT
ARE
CRITICAL
TO SAFE
OPERATION
ARE
IDENTIFIED IN THIS MANUAL.
FOLLOW THESE PRO-
CEDURES WHENEVER
CRITICAL COMPONENTS ARE
REPLACED OR IMPROPER OPERATION IS SUSPECTED.
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
0.5mA
(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 instru-
3
+
nents.
=
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 volt-
meter.
The
"limit"
indication
is 0.75V,
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)
ATTENTION
AU COMPOSANT
AYANT
RAPPORT
A LA 'SECURITE!!
;
LES COMPOSANTS
IDENTIFIES PAR
UN TRAME
ET
UNE
MARQUE
SUR
LES
DIAGRAMMES
SCHE-
MATIQUES,
LES VUES EXPLOSEES ET LA LISTE DES
PIECES
SONT
CRITIQUES
POUR
LA SECURITE
DE
FONCTIONNEMENT.
NE
REMPLACER
CES COMPO.
SANTS
QUE
PAR
DES
PIECES
SONY
DONT
LES
NUMEROS SONT DONNES DANS CE MANUEL OU DES
SUPPLEMENTS PUBLIES PAR SONY.
LES REGLAGES
DU
CIRCUIT
QUI
SONT
CRITIQUES
POUR
LA SE-
CURITE
DE
FONCTIONNEMENT
SONT
IDENTIFIES -
DANS
CE
MANUEL.
PLACES OU LE FONCTIONNEMENT
IMPROPRE EST
SUSPECTE.
|
|
SUIVRE
LES PROCEDURES =
QUAND
LES COMPOSANTS
CRITIQUES SONT
REM.
~
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