61R-WP5H
55R-WP5H
SERVICING PRECAUTIONS
CAUTION: Before servicing instruments covered b7.y Do not apply thisAC power to this instrument and/or any of its
service data and its supplements and addenda, read andelectrical assemblies unless all solid-state device heat-
follow the SAFETY PRECAUTIONS on page 3 of thissinks are correctly installed.
publication.
NOTE: If unforeseen circumstances create conflict betw8. Alweenays connect the test instrument ground lead to the
the following servicing precautions and any of the safappropretyiate instrument chassis ground before connecting
precautions on page 3 of this publication, always the test instrfollow theument positive lead. Always remove the test
safety precautions. Remember: Safety First.instrument ground lead last.
General Servicing Guidelines9. Use with this instrument only the test fixtures specified in
1. Always unplug the instrument AC power cord from the this serACvice data.
power source before: CAUTION: Do not connect the test fixture ground strap
a. Removing or reinstalling any component, circuitto any heatsink in this instrument.
board, module, or any other instrument assembly.
Electrostatically Sensitive (ES) Devices
b. Disconnecting or reconnecting any instrSome semiconductor (solid state) deumentvices can be damaged
electrical plug or other electrical connection.easily by static electricity. Such components commonly are
called Electrostatically Sensitive (ES) Devices. Examples of
c. Connecting a test substitute in parallel typical ES dewith anvices are integrated circuits and some field-
electrolytic capacitor in the instrument.effect transistors and semiconductor Ochip� components. The
CAUTION: A wrong part substitution or incorrectfollowing techniques should be used to help reduce the
polarity installation of electrolyticincidence of component damage caused by static electricity.
capacitors may result in an explosion
hazard.1. Immediately before handling any semiconductor
component or semiconductor-equipped assembly, drain
d. Discharging the picture tube anode.off any electrostatic charge on your body by touching a
known earth ground. Alternatively, obtain and wear a
2. Test high voltage only by measuring it with an approprcommercially aiatevailable discharging wrist strap device,
high voltage meter or other voltage measuring which should be remodeviceved for potential shock reasons
(DVM, FETVOM, etc.) equipped with a suitable prhighior to applying power to the unit under test.
voltage probe. Do not test high vOdroltage awing anby
arc.� The H.V. Distribution Box has an inter&nal 2.400MAfter removing an electrical assembly equipped with ES
resistor (bleeder resistor) connected from the highdevices, place the assembly on a conductive surface
voltage to ground. After power is removed from thesuch as aluminum foil, to prevent electrostatic charge
instrument the high voltage will discharge through buildup or theexposure of the assembly.
high voltage bleeder resistor. If the tubes have high
voltage after power is removed, then the bleeder 3. Use only a gresistorrounded-tip soldering iron to solder or
is defective or the bleeder ground is disconnected.desolder ES devices.
3. Discharge the picture tubeOs anode at any of the R, G, or4. Use only can anti-static type solder removal device.
B outputs on the H.V. Distribution Box only by Some solder remo(a) firstval devices not classified as Oanti-
connecting one end of an insulated clip lead to thestatic� can generate electrical charges sufficient to
degaussing or kine aquadag grounding system shield atdamage ES device.
the point where the picture tube socket ground lead is
connected, and then (b) touch the other end of the5. Do not use freon-propelled chemicals. These can
insulated clip lead to the picture tube high vgeneroltageate electrical charges sufficient to damage ES
distribution box R, G, or B output, using an insulateddevices.
handle to avoid personal contact with high voltage.
6. Do not remove a replacement ES device from its
4. Do not spray chemicals on or near this instrument protectivor anye package until immediately before you are
of its assemblies.ready to install it. (Most replacement ES devices are
packaged with leads electrically shorted together by
5. Unless specified otherwise in these service data, cleanconductive foam, aluminum foil or comparable conductive
electrical contracts by applying the following matermixture ial.)to
the contacts with a pipe cleaner, cotton-tipped stick or
comparable nonabrasive applicator: 10% (by v7.olume)Immediately before removing the protective material from
Acetone and 90% (by volume) isopropyl alcohol (90%-the leads of a replacement ES device, touch the
99% strength). protective material to the chassis or circuit assembly into
CAUTION: This is a flammable mixture. Unlesswhich the device will be installed.
specified otherwise in these service CAdata,UTION: Be sure no power is applied to the chassis or circuit,
lubrication of contacts is not required.and observe all other safprecautionsety .
6. Do not defeat any plug/socket B+ voltage inter8.locMinimizks withe bodily motions when handling unpackaged
which instruments covered by this service data might bereplacement ES devices. (Otherwise harmless motion
equipped.such as the brushing together of your clothes fabric or
the lifting of your foot from a carpeted floor can generate
static charges.
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ACEC
