Servicing Notes; Leakage Test - Sony PMC-D305 Service Manual

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 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 2 V AC range are suitable. (See Fig. A)
To Exposed Metal
Parts on Set
0.15 µ F
Fig. A. Using an AC voltmeter to check AC leakage.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK ! OR DOTTED LINE
WITH MARK ! 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 ! SUR
LES DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES
PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ DE
FONCTIONNEMENT. NE REMPLACER CES COM- POSANTS
QUE PAR DES PIÈCES SONY DONT LES NUMÉROS SONT
DONNÉS DANS CE MANUEL OU DANS LES SUPPLÉMENTS
PUBLIÉS PAR SONY.
SECTION 1

SERVICING NOTES

AC
1.5 k Ω
voltmeter
(0.75 V)
Earth Ground
CHUCK PLATE JIG ON REPAIRING
On repairing CD section, playing a disc without the CD lid, use
Chuck Plate Jig.
• Code number of Chuck Plate Jig: X-4918-255-1
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
The laser diode in the optical pick-up block may suffer electro-
static breakdown because of the potential difference generated by
the charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic breakdown 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 emis-
sion, observe from more than 30 cm away from the objective lens.
This Compact Disc player is classiffied as a
CLASS 1 LASER product.
The CLASS 1 LASER PRODUCT table is
location on the rear exterior.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous ra-
diation exposure.
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