PMC-DR45 - Sony Audio Service Manual (repair manual). Page 3

Read Sony PMC-DR45 Service Manual online

– 3 –
This Compact Disc player is
classified as a CLASS 1
LASER product.
The CLASS 1 LASER
PRODUCT lable is located
on the bottom exterior.
SECTION 1
SERVICING NOTES
CAUTION
Use of controls or adjustments or performance of proce-
dures other than those specified herein may result in haz-
ardous radiation exposure.
Flexible Circuit Board Repairing
Keep the temperature of the soldering iron around 270˚C during
repairing.
Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
Be careful not to apply force on the conductor when soldering
or unsoldering.
Notes on Chip Component Replacement
Never reuse a disconnected chip component.
Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK
OR BASE UNIT
The laser diode in the optical pick-up block may suffer electrostatic
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 emission,
observe from more than 30 cm away from the objective lens.
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  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 
0
 SUR LES
DIAGRAMMES SCHÉMATIQUES ET LA LISTE  DES PIÈCES SONT
CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT. NE
REMPLACER CES COMPOSANTS QUE PAR DES PIÈCES SONY
DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU
DANS LES SUPPLÉMENTS PUBLIÉS PAR SONY.
To Exposed Metal
Parts on Set
0.15µF
1.5k
AC
voltmeter
(0.75V)
Earth Ground
Fig. A. Using an AC voltmeter to check AC leakage.
SAFETY  CHECK-OUT
After correcting the original service problem, perform the following
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 2V AC range are suitable. (See Fig. A)
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