SERVICING PRECAUTIONS
CAUTION : Before servicing the A/V Receiver covered by thisElectrostatically Sensitive (ES) Devices
service data and its supplements and addends, read and follow theSome semiconductor (solid state) devices can be damaged easily by
SAFETY PRECAUTIONS. NOTE : if unforeseen circumstancesstatic electricity. Such components commonly are called
create conflict between the following servicing precautions and anyElectrostatically Sensitive (ES) Devices. Examples of typical Es
of the safety precautions in this publication, always follow the safetydevices are integrated circuits and some field effect transistors and
precautions.semiconductor chip components.
Remember Safety First:The following techniques should be used to help reduce the
incidence of component damage caused by static electricity.
General Servicing Precautions
1. Always unplug the A/V Receiver AC power cord from the AC1. Immediately before handling any semiconductor component or
power source before:semiconductor-equipped assembly, drain off any electrostatic
(1) Removing or reinstalling any component, circuit board,charge on your body by touching a known earth ground.
module, or any other assembly.Alternatively, obtain and wear a commercially available
(2) Disconnecting or reconnecting any internal electrical plug ordischarging wrist strap device, which should be removed for
other electrical connection.potential shock reasons prior to applying power to the unit under
(3) Connecting a test substitute in parallel with an electrolytictest.
capacitor.
Caution : A wrong part substitution or incorrect polarity installation2. After removing an electrical assembly equipped with ES devices,
of electrolytic capacitors may result in an explosion hazard.place the assembly on a conductive surface such as aluminum
foil, to prevent electrostatic charge buildup or exposure of the
2. Do not spray chemicals on or near this A/V Receiver or any of itsassembly.
assemblies.
3. Use only a grounded-tip soldering iron to solder or unsolder ES
3. Unless specified otherwise in this service data, clean electricaldevices.
contacts by applying an appropriate contact cleaning solution to
the contacts with a pipe cleaner, cottontipped swab, or4. Use only an antistatic solder removal device. Some solder
comparable soft applicator.removal devices not classified a ?anti-static? can generate
Unless specified otherwise in this service data, lubrication ofelectrical charges sufficient to damage ES devices.
contacts is not required.
5. Do not use freonpropelled chemicals. These can generate
4. Do not defeat any plug/socket B+ voltage interlocks with whichelectrical charge sufficient to damage ES devices.
instruments covered by this service manual might be equipped.
6. Do not remove a replacement ES device from its protective
5. Do not apply AC power to this A/V Receiver and/or any of itspackage until immediately before you are ready to install it. (Most
electrical assemblies unless all solid-state device heat sinks arereplacement ES devices are packaged with leads electrically
correctly installed.shorted together by conductive foam, aluminum foil, or
comparable conductive material).
6. Always connect test instrument ground lead to the appropriate
ground before connecting the test instrument positive lead. Always7. lmmediately before removing the protective material from the
remove the test instrument ground lead last.leads of a replacement ES device, touch the protective material to
the chassis or circuit assembly into which the device will be
Insulation Checking Procedureinstalled.
Disconnect the attachment plug from the AC outlet and turn the
power on. Connect an insulation resistance meter(500V) to theCaution : Be sure no power is applied to the chassis or circuit, and
blades of the attachment plug. The insulation resistance betweenobserve all other safety precautions.
each blade of the attachment plug and accessible conductive parts
(Note 1) should be more than 1M-ohm.8. Minimize bodily motions when handing unpackaged replacement
Note 1 : Accessible Conductive Parts including Metal panels, InputES devices. (Normally harmless motion such as the brushing
terminals, Earphone jacks, etc.together of your clothes fabric or the lifting of your foot from a
carpeted floor can generate static electricity sufficient to damage
an ES device.) |
ACEC
NAD
