PMC-D305, PMC-D305L - Sony Audio Service Manual (repair manual). Page 3

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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)
Fig. A.
Using an AC voltmeter to check AC leakage.
1.5 k
0.15 
µ
F
AC
voltmeter
(0.75 V)
To Exposed Metal
Parts on Set
Earth Ground
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous ra-
diation exposure.
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.
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
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
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.
SECTION  1
SERVICING  NOTES
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