Sony dvpns 975 v service manual

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– 2 – DVP-NS975V SAFETY CHECK-OUT 1. Check the area of your repair for unsoldered or poorly-soldered connections. Check the entire board surface for solder splashes and bridges. 2. Check the interboard wiring to ensure that no wires are pinched or contact high-wattage resistors. 3. Look for unauthorized replacement parts, particularly transis- tors, 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 their replacement. 5. Check the line cord for cracks and abrasion. Recommend the replacement of any such line cord to the cus- tomer. 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. WARNING!! 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 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!! 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. After correcting the original service problem, perform the following safety checks before releasing the set to the customer: 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 0.5mA (500 microampers). 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 volmeter. 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) Unleaded solder 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 highter than 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 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.  Usable with ordinary solder It is best to use only unleaded solder but unleaded solder may also be added to ordinary solder. ATTENTION AU COMPOSANT AYANT RAPPORT À LA SÉCURITÉ! LES COMPOSANTS IDENTIFÉS PAR UNE MARQUE 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. To Exposed Metal Parts on Set 0.15 F 1.5k AC Voltmeter (0.75 V) Earth Ground Fig.A. Using an Acvoltmeter to check AC leakage.