Sony LBT-G3000 Service Manual page 3

Supplied accessories
FM wire antenna (1)
AM loop antenna (1)
Remote commander RM-S221 (1)
Batteries Sony SUM-3 (NS) — (2)
Design and specifications are subject to change without notice.
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
The laser diode in the optical pick-up block may suffer
electrostatic break-down because of the potential difference
generated by the charged electrostatic load, etc. on clothing
and the human body.
During repair, pay attention to electrostatic break-down and
also use the procedure in the printed matter which is included
in the repair parts.
The flexible board is easily damaged and should be handled
with care.
NOTES ON LASER DIODE EMISSION CHECK
The laser beam on this model is concentrated so as to be
focused on the disc reflective surface by the objective lens in
the optical pick-up block. Therefore, when checking the laser
diode emission, observe from more than 30 cm away from the
objective lens.
Dolby noise reduction manufactured under license from Dolby Labora-
tories Licensing Corporation.
"DOLBY" and the double-D symbol (1 are trademarks of Dolby Labora-
tories Licensing Corporation.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK A OR DOTTED LINE WITH
MARK A 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.
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 ex-
posed metal part having a return to chassis, must not
exceed 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 instru-
ments.
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 7.5V, 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 20V AC range are
suitable. (See Fig. A)
To Exposed Metal
Parts on Set
AC
vo/tmeter
(7,8V)
= Earth Ground
Fig. A. Using an AC voltmeter to check AC leakage.
ATTENTION AU COMPOSANT AYANT RAPPORT
A LA SECURITE!
LES COMPOSANTS IDENTIFIES PAR UNE MARQUE /\ SUR LES DIA-
GRAMMES SCHEMATIQUES ET LA LISTE DES PIECES SONT CRI-
TIQUES POUR LA SECURITE DE FONCTIONNEMENT. NE REMPLACER
CES COMPOSANTS QUE PAR DES PIECES SONY DONT LES NUMEROS
SONT DONNES DANS CE MANUEL OU DANS LES SUPPLEMENTS
PUBLIES PAR SONY.
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