CNU-500
The material contained in this manual consists of
information that is the property of Sony Corporation and
is intended solely for use by the purchasers of the
equipment described in this manual.
Sony Corporation expressly prohibits the duplication of
any portion of this manual or the use thereof for any
purpose other than the operation or maintenance of the
equipment described in this manual without the express
written permission of Sony Corporation.
Le matériel contenu dans ce manuel consiste en
informations qui sont la propriété de Sony Corporation et
sont destinées exclusivement à l’usage des acquéreurs
de l’équipement décrit dans ce manuel.
Sony Corporation interdit formellement la copie de
quelque partie que ce soit de ce manuel ou son emploi
pour tout autre but que des opérations ou entretiens de
l’équipement à moins d’une permission écrite de Sony
Corporation.
Das in dieser Anleitung enthaltene Material besteht aus
Informationen, die Eigentum der Sony Corporation sind,
und ausschließlich zum Gebrauch durch den Käufer der
in dieser Anleitung beschriebenen Ausrüstung bestimmt
sind.
Die Sony Corporation untersagt ausdrücklich die
Vervielfältigung jeglicher Teile dieser Anleitung oder den
Gebrauch derselben für irgendeinen anderen Zweck als
die Bedienung oder Wartung der in dieser Anleitung
beschriebenen Ausrüstung ohne ausdrückliche
schriftliche Erlaubnis der Sony Corporation.
SAFETY CHECK-OUT
After correcting the original service problem,
perform the following safety checks before
releasing the set to the customer :
Check the metal trim, “metallized” knobs, screws,
and all other exposed metal parts for AC
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 3.5 mA. 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 5.25 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 20 V AC range
are suitable. (See Fig. A)
Fig A. Using an AC voltmeter to check AC leakage.
To Exposed Metal
Parts on Set
1.5 k
Z
0.15
µ
F
AC
voltmeter
(5.25V)
Earth Ground
Summary of Contents for CNU-500
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