Sony HT-CT180 Service Manual page 2

HT-CT180
Copyrights and Trademarks
This system incorporates Dolby* Digital
Surround System.
* Manufactured under license from
Dolby Laboratories.
Dolby, and the double-D symbol are
trademarks of Dolby Laboratories.
®
The BLUETOOTH word mark and logos
are registered trademarks owned by
Bluetooth SIG, Inc. and any use of such
marks by Sony Corporation is under
license.
The N Mark is a trademark or registered
trademark of NFC Forum, Inc. in the
United States and in other countries.
Android™ is a trademark of Google Inc.
"ClearAudio+" is a trademark of Sony
Corporation.
Other trademarks and trade names are
those of their respective owners.
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
WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS
MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.
2
WITH SONY PARTS
SAFETY CHECK-OUT
After correcting the original service problem, perform the follow-
ing safety check 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 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 0.5 mA (500 microamperes.).
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 2 V AC range are suitable. (See
Fig. A)
To Exposed Metal
Parts on Set
0.15 μF
Fig. A. Using an AC voltmeter to check AC leakage.
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 FONC-
TIONNEMENT. NE REMPLACER CES COMPOSANTS QUE
PAR DES PIÈCES SONY DONT LES NUMÉROS SONT DON-
NÉS DANS CE MANUEL OU DANS LES SUPPLÉMENTS
PUBLIÉS PAR SONY.
AC
1.5 kΩ voltmeter
(0.75 V)
Earth Ground