Sony MDS-PC3 - Manual (Page 5)

5
SECTION 1
SERVICE NOTES
This appliance is classified as a
CLASS 1 LASER product. The
CLASS 1 LASER PRODUCT
MARKING is located on the
rear exterior.
Laser component in this product is capable
of emitting radiation exceeding the limit for
Class 1.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radia-
tion exposure.
Notes on chip component replacement
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be
damaged by heat.
Flexible Circuit Board Repairing
• Keep the temperature of 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 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
Never look into the laser diode emission from right above when
checking it for adjustment. It is feared that you will lose your sight.
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 IDENTIFÉS 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 PIÈSES SONY
DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU
DANS LES SUPPÉMENTS PUBLIÉS PAR SONY.
This caution
label is located
inside the unit.
Lead free soldering
MAIN and PANEL boards of this product are lead free soldered
(contains no lead).
Lead-free solder have the following characteristics.
• The melting point is about 40 ºC higher than conventional solder.
Conventional soldering iron can be used, but must be pressed for
a longer time.
When using the soldering iron with a temperature adjustment func-
tion, set to about 350 ºC.
Note: Pressing the soldering iron too long may cause the board pat-
tern (copper coating) to peel off.
• Strong viscosity
As it has stronger viscosity than conventional solder, make sure
the IC terminal does not solder bridge.
• Can be used with conventional solder
Though it is best to add lead-free solder only, conventional solder
can also be added.
• Boards using lead-free solder are printed with the LF mark mean-
ing “Lead Free”.
Fig. A. Using an AC voltmeter to check AC leakage.
1.5 k Ω 0.15 µ F
AC
voltmeter
(0.75 V)
To Exposed Metal
Parts on Set
Earth Ground
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 microamperes). Leak-
age 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 pas-
sive VOM that is suitable. Nearly all battery operated digital
multimeters that have a 2 V AC range are suitable. (See Fig. A)