Servicing Note - Sony CDP-CX70ES Service Manual

SAFETY CHECK-OUT
After correcting the original service problem, perform the follow-
ing safety checks before releasing the set to the customer:
Check the antenna termmals, metal trim, "metallized" knobs, screws,
and all other exposed metal parts for AC leakage. Check leakage as
described below.
LEAKAGE
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 rnA (500 microampers). Leak-
age current can be measured by any one of three methods.
I. A commercial leakage tester, such as the Simpson 229 or RCA
WT-540A. Follow the manufacturers' mstructions to use these
mstruments.
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 YOM
or battery-operated AC voltmeter. The "hmit" indicatiOn is 0. 75
Y, so analog meters must have an accurate low-voltage scale.
The Simpson 250 and Sanwa SH-63Trd are examples of a pas-
sive YOM that is suitable. Nearly all battery operated digital
multimeters that have a 2Y AC range are smtable. (See Fig. A)
0 1511F
To Exposed Metal
Parts on Set
1.5/<Q
..,. Earth Ground
AC
voltmeter
(0 75V)
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.
SECTION 1
SERVICING NOTE
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 clothmg and the human body.
During repair, pay attention to electrostatic breakdown and also use
the procedure in the printed matter which is mcluded 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 d1sc reflective surface by the objective lens m the optical pick-
up block. Therefore, when checking the laser diode emiss10n, ob-
serve from more than 30 em away from the objective lens.
LASER DIODE AND FOCUS SEARCH OPERATION
CHECK
Carry out the "S curve check" m "CD section adjustment" and check
that the S curve waveform is output repeatedly.
ATTENTION AU COMPOSANT AVANT RAPPORT
A
LA SECURITE!!
LES COMPOSANTS IDENTIFIES PAR UNE MARQUE LtSUR
LES DIAGRAMMES SCHEMATIQUES ET LA LISTE DES
PIECES SONT CRITIQUES POUR LA SECURITE DE
FONCTIONNEMENT. NE REM PLACER 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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