Daewoo DV-K8J5A Technical Manual

Contents

Daewoo DV-K8J5A Technical Manual Manual pdf 3 page image

21. Before returning the instrument to the customer always makea safety check of the entire instrument including but not limitedto the following items.a. Be sure that no built-in protective devices are defectiveand/or have been defeated during servicing (1) Protectiveshields are provided on this instrument to protect both thetechnician and the customer. Correctly replace all missingprotective shields. including any removed for servicing con-venience. (2) When reassembling the instrument be sure toput back in place all protective device including but not lim-ited to nonmetallic control knobs insulating fishpapersadjustment and compartment covers/shields and isolationresistor capacitor networks. Do not operate this instru-ment or permit it to be operated without all protectivedevices correctly installed and functioning. Servicerswho defeat safety features or fail to perform safetychecks may be liable for any resulting damage, and mayexpose themselves and others to possible injury.b. Be sure that there are no cabinet openings through which anadult or child might be able to insert their fingers and con-tact a hazardous voltage. Such openings include but are notlimited to (1) excessively wide cabinet ventilation slots and(2) improperly fitted and/or incorrectly secured cabinet cov-ers.c. Leakage Cold Check – With the instrument AC plugremoved from any AC source, connect an electrical jumperacross the two AC plug prongs. Place the instrument ACswitch in the on position. Connect one lead of an ohmmeterto the AC plug prongs tied together and touch the otherohmmeter lead in turn to each push button/customer controlexposed metal screws, metalized overlays and to eachcable connector. If the measured resistance is less than 1.0megohm or greater than 5.2 megohm an abnormality existsthat must be corrected before the instrument is returned tothe customer. Repeat this test with the AC switch in the offposition.AC Leakage Testd. Leakage Current Hot CheckOn completely assembled instrument, plug the AC line corddirectly into a 120V AC outlet. (Do not use an isolation trans-former during this test). Use a leakage current tester or ametering system that complies with American NationalStandards Institute (ANSI) C101.1 Leakage Current forAppliances and Underwriters Laboratories (UL) 1410, (59.7).Measure for current from a known earth ground (metalwaterpipe, conduit, etc.) to all exposed metal or conductiveparts of the instrument (antenna connections, handle brack-et, metal cabinet, screwheads, metallic overlays, push-but-tons, control shafts, etc.) especially any exposed metal partsthat ofter an electrical return path to the chassis. Any currentmeasured must not exceed 0.5 milliamp. Reverse the instru-ment power cord plug in the outlet and repeat the test.ANY MEASUREMENTS NOT WITHIN THE LIMITS SPECI-FIED HEREIN INDICATE A POTENTIAL SHOCK HAZARDTHAT MUST BE ELIMINATED BEFORE RETURNING THEINSTRUMENT TO THE CUSTOMER OR BEFORE CON-NECTING TO ANTENNA OR ACCESSORIES.e. Interconnected Equipment AC Leakage TestAvoid shock hazards The instrument, accessory or cable(s)to which this instrument is connected should have theapplicable sections of the leakage resistance cold checkand the leakage current hot check performed Do not con-nect this instrument to an antenna cable or accessory thatexhibits excessive leakage currents.2. Read and comply with all caution and safety-related notes on orinside the instrument cabinet and on the chassis.3. Design Alteration Warning – Do not alter or add to the mechan-ical or electrical design of this instrument. Design alterationsand additions, including, but not limited to circuit modificationsand the addition of items such as auxiliary audio output con-nections cables and accessories etc might alter the safety char-acteristics of this instrument and create a hazard to the userAny design alterations or additions will void the manufacturer'swarranty and will make you the servicer responsible for person-al injury or property damage resulting therefrom.4. Observe original lead dress Take extra care to assure correctlead dress in the following areas a near sharp edges b nearthermally hot parts – be sure that leads and components do nottouch thermally hot parts and c the AC supply Always inspect inall areas for pinched out-of-place or frayed wiring Do notchange spacing between components and between compo-nents and the printed-circuit board Check AC power cord fordamage.5. Components parts and/or wiring that appear to have overheatedor are otherwise damaged should be replaced with compo-nents, parts, or wiring that meet original specifications.Additionally determine the cause of overheating and/or damageand if necessary take corrective action to remove any potentialsafety hazard.6. PRODUCT SAFETY NOTICE – Many electrical and mechanicalparts have special safety-related characteristics some of whichare often not evident from visual inspection nor can the protec-tion they give necessarily be obtained by replacing them withcomponents rated for higher voltage, wattage, etc. Parts thathave special safety characteristics are identified in this servicedata by a star (¡ ) on schematics and a (¡ ) in the parts list. Useof a substitute replacement that does not have the same safetycharacteristics as the recommended replacement part in thisservice data parts list might create shock, fire, and/or otherhazards. Product Safety is under review continuously and newinstructions are issued whenever appropriate. For the latestinformation, always consult the appropriate current service liter-ature.DEVICEUNDERTESTTEAKAGECURRENTTESTERTEST ALLEXPOSED METALSURFACES2WIRE CORDALSO TEST WITHPLUG REVERSEDDSING AC ADAPTERPCUG AS REOUIREDEARTHGROUNDREADING SHOULDNOT BE ABOVE0.5mASAFETY PRECAUTIONS