NAD S570 Service Manual

Also see for S 570: Owner's manual

Contents

NAD S570 Service Manual Manual pdf 3 page image

1-5SERVICING PRECAUTIONSCAUTION:Before servicing the DVD player covered by this servicedata and its supplements and addends, read and followthe SAFETY PRECAUTIONS. NOTE: if unforeseencircumstances create conflict between the followingservicing precautions and any of the safety precautions inthis publications, always follow the safety precautions.Remembers Safety First:General Servicing Precautions1. Always unplug the DVD player AC power cord from the ACpower source before:(1) Removing or reinstalling any component, circuit board,module, or any other assembly.(2) Disconnection or reconnecting any internal electricalplug or other electrical connection.(3) Connection a test substitute in parallel with anelectrolytic capacitor.Caution: A wrong part substitution or incorrect polarityinstallation of electrolytic capacitors may result in anexplosion hazard.2. Do not spray chemicals on or near this DVD player orany of its assemblies.3. Unless specified otherwise in this service data, cleanelectrical contacts by applying an appropriate contactcleaning solution to the contacts with a pipe cleaner,cottontipped swab, or comparable soft applicator.Unless specified otherwise in this service data, lubricationof contacts is not required.4. Do not defeat any plug/socket B+ voltage interlockswith which instruments covered by this service manualmight be equipped.5. Do not apply AC power to this DVD player and/or anyof its electrical assemblies unless all solid-state deviceheat sinks are correctly installed.6. Always connect test instrument ground lead to theappropriate ground before connection the test instrumentpositive lead. Always remove the test instrument groundlead last.Insulation Checking ProcedureDisconnect the attachment plug from the AC outlet andturn the power on. Connect an insulation resistancemeter (500V) to the blade of the attachment plug. Theinsulation resistance between each blade of theattachment plug and accessible conductive parts (Note 1)should be more than 1M-ohm.Note 1: Accessible Conductive Parts including Metalpanels, Input terminals, Earphone jacks, etc.Electrostatically Sensitive (ES) DevicesSome semiconductor (solid state) devices can be damagedeasily by static electricity. Such components commonly arecalled Electrostatically Sensitive (ES) Devices. Examples oftypical Es devices are integrated circuits and some fieldeffect transistors and semiconductor chip components.The following techniques should be used to help reduce theincidence of component damage caused by static electricity.1. Immediately before handing any semiconductorcomponent or semiconductor equipped assembly, drainoff any electrostatic charge on your body by touching aknown earth ground. Alternatively, obtain and wear acommercially available discharging wrist strap device,which should be removed for potential shock reasonsprior to applying power to the unit under test.2. After removing an electrical assembly equipped with ESdevices, place the assembly on a conductive surface suchan aluminum foil, to prevent electrostatic charge buildupor exposure of the assembly.3. Use only a grounded-tip soldering iron to solder orunsolder ES devices.4. Use only an antistatic solder removal device. Somesolder removal devices not classified an “antistati c” cangenerate electric charges sufficient to damage ESdevices.5. Do not use freonpropelled chemicals. These cangenerate electrical charge sufficient to damage ESdevices.6. Do not remove a replacement ES device from its protecttive package until immediately before you are ready toinstall it. (Most replacement ES devices are packagedwith leads electrically shorted together by conductivefoam, aluminum foil, or comparable conductive material).7. Immediately before removing the protective materialfrom the leads of a replacement ES device, touch theprotective material to the chassis or circuit assembly intowhich the device will be installed.Caution: Be sure no power is applied to the chassis orcircuit, and observe all other safety precautions.8.Minimize bodily motions when handing unpackagedreplacement ES devices. (Normally harmless motionsuch as the brushing together of your clothes fabric orthe lifting of your foot from a carpeted floor can generatestatic electricity sufficient to damage an ES device.)