General Servicing Precautions - Haier TV-8888-30 Service Manual

GENERAL SERVICING PRECAUTIONS

1. Always unplug the receiver AC power cord from the AC power source before:
a. Removing or reinstalling any component, circuit board module or any other
assembly of the receiver.
b. Disconnecting or reconnecting any receiver electrical plug or other electrical
connection.
c. Connecting a test substitute in parallel with an electrolytic capacitor in the
receiver.
CAUTION: A wrong substitution part or incorrect installation polarity of electrolytic
capacitors may result in an explosion.
d. Discharging the picture tube anode.
2. Test high voltage only by measuring it with an appropriate high voltage meter or
other voltage-measuring device (DVM, FETVOM, etc.) equipped with a suitable
high voltage probe. Do not test high voltage by "drawing an arc".
3. Discharge the picture tube anode only by
(a) First connecting one end of an insulated clip lead to the degaussing or kine
aquadag grounding system shield at the point where the picture tube socket ground
lead is connected, and then
(b) Touch the other end of the insulated clip lead to the picture tube anode button,
using an insulating handle to avoid personal contact with high voltage.
4. Do not spray chemicals on or near this receiver or any of its assemblies.
5. Unless specified otherwise in this service manual, clean electrical contacts only by
applying the following mixture to the contacts with a pipe cleaner, cotton-tipped
stick or comparable nonabrasive applicator; 10% (by volume) Acetone and 90%
(by volume) isopropyl alcohol (90%-99% strength)
CAUTION: This is a flammable mixture.
Unless specified otherwise in this service manual, lubrication of contacts is not
required.
6. Do not defeat any plug / socket B+ voltage interlocks with which receivers
covered by this service manual might be equipped.
7. Do not apply AC power to this instrument and/or any of its electrical assemblies
unless all solid-state device heat sinks are correctly installed.
8. Always connect the test receiver ground lead to the receiver chassis ground
before connecting the test receiver positive lead.
Always remove the test receiver ground lead last.
9. Use with this receiver only the test fixtures specified in this service manual.
CAUTION: Do not connect the test fixture ground strap to any heat sink in this
receiver.
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