LC37/LC37F
SERVICING PRECAUTIONS
CAUTION: Before servicing instruments covered by this service1. Immediately before handling any semiconductor component or
data and its supplements and addenda, read and follow the SAFE-semiconductor-equipped assembly, drain off any electrostatic
TY PRECAUTIONS on page 2 of this publication.charge on your body by touching a known earth ground.
NOTE: If unforseen circumstances create conflict between the fol-Alternatively, obtain and wear a commercially available dis-
lowing SERVICING PRECAUTIONS and any of the SAFETY PRE-charging wrist strap device, which should be removed for poten-
CAUTIONS on page 2 of this publication, always follow the SAFETYtial shock reasons prior to applying power to the unit under test.
PRECAUTIONS.
Remember: Safety First.2. After removing an electrical assembly equipped with ES
devices, place the assembly on a conductive surface such as
General Servicing Guidelinesaluminum foil, to prevent electrostatic charge build-up or expo-
1. Always unplug the instrument AC power cord from the AC powersure of the assembly.
source before:
a. Removing or reinstalling any component, circuit board, 3. Use only a grounded-tip soldering iron to solder or desolder ES
module, or any other instrument assembly.devices.
b. Disconnecting or reconnecting any instrument electrical 4. Use only an anti-static type solder removal device. Some sol-
plug or other electrical connection.der removal devices not classified as ?anti-static? can generate
electrical charges sufficient to damage ES device.
c. Connecting a test substitute in parallel with an electrolyt-
ic capacitor in the instrument.5. Do not use freon-propelled chemicals. These can generate
CAUTION: A wrong part substitution or incorrect electrical charges sufficient to damage ES devices.
polarity installation of electrolytic
capacitors may result in an 6. Do not remove a replacement ES device from its protective
explosion hazard.package until immediately before you are ready to install it.
(Most replacement ES devices are packaged with leads electri-
2. Do not spray chemicals on or near this instrument or any of itscally shorted together by conductive foam, aluminum foil or
assemblies.comparable conductive material.)
3. Unless specified otherwise in these service data, clean electri-7. Immediately before removing the protective material from the
cal contacts by applying the following mixture to the contactsleads of a replacement ES device, touch the protective material
with a pipe cleaner, cotton-tipped stick or comparable nonabra-to the chassis or circuit assembly into which the device will be
sive applicator: 10% (by volume) Acetone and 90% (by volume)installed.
ispropyle alchohol (90%-99% strength).CAUTION: Be sure no power is applied to the chassis or
CAUTION: This is a flammable mixture. Unless specified circuit, and observe all other safety precautions.
otherwise in these service data, lubrication of
contacts is not required.8. Minimize bodily motions when handling unpackaged replace-
ment ES devices. (Otherwise harmless motion such as the
4. Do not defeat any plug/socket B+ voltage interlocks with whichbrushing together of your clothes fabric or the lifting of your foot
instruments covered by this service data might be equipped.from a carpeted floor can generate static electricity sufficient to
damage an ES device.)
5. Do not apply AC power to this instrument and/or any of its elec-
trical assemblies unless all solid-state device heat-sinks are cor-
rectly installed.
6. Always connect the test instrument ground lead to the appropri-
ate instrument chassis ground before connecting the test instru-
ment positive lead. Always remove the test instrument ground
lead last.
7. Use with this instrument only the test fixtures specified in this
service data.
CAUTION: Do not connect the test fixture ground strap to
any heatsink in this instrument.
Electrostatically Sensitive (ES) Devices
Some semiconductor (solid state) devices can be damaged easily
by static electricity. Such components commonly are called
Electrostatically Sensitive (ES) Devices. Examples of typical ES
devices are integrated circuits and some field-effect transistors and
semiconductor ?chip? components. The following techniques should
be used to help reduce the incidence of component damage caused
by static electricity.
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