DVP-NC675P
SAFETY CHECK-OUT
After correcting the original service problem, perform the following
safety checks before releasing the set to the customer.
1.Check the area of your repair for unsoldered or poorly-solderedLEAKAGE TEST
connections. Check the entire board surface for solder splashes
and bridges.The AC leakage from any exposed metal part to earth ground and
2.Check the interboard wiring to ensure that no wires arefrom all exposed metal parts to any exposed metal part having a
"pinched" or contact high-wattage resistors.return to chassis, must not exceed 0.5mA (500 microampers).
3.Look for unauthorized replacement parts, particularlyLeakage current can be measured by any one of three methods.
transistors, that were installed during a previous repair. Point
them out to the customer and recommend their replacement.1.A commercial leakage tester, such as the Simpson 229 or RCA
4.Look for parts which, though functioning, show obvious signsTW-540A. Follow the manufacturers' instructions to use these
of deterioration. Point them out to the customer andinstruments.
recommend their replacement.2.A battery-operated AC milliammeter. The Data Precision 245
5.Check the line cord for cracks and abrasion.digital multimeter is suitable for this job.
Recommend the replacement of any such line cord to the3.Measuring the voltage drop across a resistor by means of a
customer.VOM or battery-operated AC voltmeter. The "limit" indication
6.Check the B+ voltage to see it is at the values specified.is 0.75V, so analog meters must have an accurate low voltage
7.Check the antenna terminals, metal trim, "metallized" knobs,scale. The Simpson 250 and Sanwa SH-63Trd are examples
screws, and all other exposed metal parts for AC leakage.of a passive VOM that is suitable. Nearly all battery operated
Check leakage as described below.digital multimeters that have a 2V AC range are suitable. (See
Fig. A)
: LEAD FREE MARK
Unleaded solder has the following characteristics.
To Exposed Metal
Unleaded solder melts at a temperature about 40°C higher thanParts on Set
ordinary solder.
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
about 350°C.AC
Voltmeter
Caution: The printed pattern (copper foil) may peel away if the0.15 ?F1.5 k
(0.75 V)
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.Earth Ground
Usable with ordinary solder
Fig. A. Using an AC voltmeter to check AC leakage.
It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.
WARNING!!
Unleaded solder
WHEN SERVICING, DO NOT APPROACH THE LASER EXIT WITHBoards requiring use of unleaded solder are printed with the lead-
THE EYE TOO CLOSELY. IN CASE IT IS NECESSARY TOfree mark (LF) indicating the solder contains no lead.
CONFIRM LASER BEAM EMISSION, BE SURE TO OBSERVE(Caution: Some printed circuit boards may not come printed with
FROM A DISTANCE OF MORE THAN 25 cm FROM THE SURFACEthe lead free mark due to their particular size.)
OF THE OBJECTIVE LENS ON THE OPTICAL PICK-UP BLOCK.
CAUTION:
The use of optical instrument with this product will increase eye
hazard.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radiation
exposure.
SAFETY-RELATED COMPONENT WARNING!!ATTENTION AU COMPOSANT AYANT RAPPORT
A LA S�CURIT�!
COMPONENTS IDENTIFIED BY MARK OR DOTTED LINE WITHLES COMPOSANTS IDENTIF�S PAR UNE MARQUE SUR LES
MARK ON THE SCHEMATIC DIAGRAMS AND IN THE PARTSDIAGRAMMES SCH�MATIQUES ET LA LISTE DES PIECES SONT
LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESECRITIQUES POUR LA S�CURIT� DE FONCTIONNEMENT. NE
COMPONENTS WITH SONY PARTS WHOSE PART NUMBERSREMPLACER CES COMPOSANTS QUE PAR DES PIESES SONY
APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTSDONT LES NUM�ROS SONT DONN�S DANS CE MANUEL OU
PUBLISHED BY SONY.DANS LES SUPP�MENTS PUBLI�S PAR SONY.
? 2 ? |
ACEC
