After correcting the original service problem, perform the following
safety checks before releasing the set to the customer:
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
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 0.75V, 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)
1. Check the area of your repair for unsoldered or poorly-soldered
connections. Check the entire board surface for solder splashes
2. Check the interboard wiring to ensure that no wires are “pinched”
or contact high-wattage resistors.
3. Look for unauthorized replacement parts, particularly transistors,
that were installed during a previous repair. Point them out to
the customer and recommend their replacement.
4. Look for parts which, though functioning, show obvious signs
of deterioration. Point them out to the customer and recommend
5. Check the line cord for cracks and abrasion. Recommend the
replacement of any such line cord to the customer.
6. Check the B+ voltage to see it is at the values specified.
7. Check the antenna terminals, metal trim, “metallized” knobs,
screws, and all other exposed metal parts for AC leakage. Check
leakage as described below.
To Exposed Metal
Parts on Set
Fig. A. Using an AC voltmeter to check AC leakage.
WHEN SERVICING, DO NOT APPROACH THE LASER
EXIT WITH THE EYE TOO CLOSELY. IN CASE IT IS
NECESSARY TO CONFIRM LASER BEAM EMISSION,
BE SURE TO OBSERVE FROM A DISTANCE OF MORE
THAN 25 cm FROM THE SURFACE OF THE OBJEC-
TIVE LENS ON THE OPTICAL PICK-UP BLOCK.
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. RE-
PLACE THESE COMPONENTS WITH SONY PARTS WHOSE
PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR
IN SUPPLEMENTS PUBLISHED BY SONY.
Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with
the lead free mark due to their particular size.)
: LEAD FREE MARK
Unleaded solder has the following characteristics.
• Unleaded solder melts at a temperature about 40°C higher than
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
Caution: The printed pattern (copper foil) may peel away if the
heated tip is applied for too long, so be careful!
• Strong viscosity
Unleaded solder is more viscous (sticky, less prone to flow) than
ordinary solder so use caution not to let solder bridges occur such
as on IC pins, etc.
The use of optical instrument with this product will increase eye
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 SUPPLÉ-
MENTS PUBLIÉS PAR SONY.
－ 2 －
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radia-