LG 42LB550A, Руководство по обслуживанию

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SERVICING PRECAUTIONS SERVICING PRECAUTIONS
CAUTION: Before servicing receivers covered by this CAUTION: Before servicing receivers covered by this service service
manual and its supplements and addenda, read and manual and its supplements and addenda, read and follow the follow the
SAFETY PRECAUTIONS SAFETY PRECAUTIONS on page 3 of this publication. on page 3 of this publication.
NOTE NOTE : If unforeseen circumstances create conict between : If unforeseen circumstances create conict between the the
following servicing precautions and any of the safety precautions following servicing precautions and any of the safety precautions
on page 3 of this on page 3 of this publication, always follow the safety precau- publication, always follow the safety precau-
tions. Remember: Safety First. tions. Remember: Safety First.
General Servicing Precautions General Servicing Precautions
1. Always unplug the receiver AC power cord 1. Always unplug the receiver AC power cord from the AC power from the AC power
source before; source before;
a. Removing or reinstalling any component, circuit board a. Removing or reinstalling any component, circuit board
module or any module or any other receiver assembly. other receiver assembly.
b. Disconnecting or reconnecting any receiver electrical plug b. Disconnecting or reconnecting any receiver electrical plug
or other electrical connection. or other electrical connection.
c. Connecting a test substitute in parallel with an electrolytic c. Connecting a test substitute in parallel with an electrolytic
capacitor in the receiver. capacitor in the receiver.
CAUTION CAUTION : A wrong part substitution or incorrect polarity : A wrong part substitution or incorrect polarity
installation of electrolytic capacitors may result in an explo- installation of electrolytic capacitors may result in an explo-
sion hazard. sion hazard.
2. T 2. T est high voltage only est high voltage only by measuring it with by measuring it with an appropriate an appropriate
high voltage meter or other voltage measuring device (DVM, high voltage meter or other voltage measuring device (DVM,
FETVOM, etc) equipped with a suitable high voltage probe. FETVOM, etc) equipped with a suitable high voltage probe.
Do not test high voltage by "drawing an Do not test high voltage by "drawing an arc". arc".
3. Do not spray chemicals on or near 3. Do not spray chemicals on or near this receiver or any of its this receiver or any of its
assemblies. assemblies.
4. Unless specied otherwise in this service manual, clean 4. Unless specied otherwise in this service manual, clean
electrical contacts only by applying the following mixture to the electrical contacts only by applying the following mixture to the
contacts with a pipe contacts with a pipe cleaner, cotton-tipped stick or comparable cleaner, cotton-tipped stick or comparable
non-abrasive applicator; 10 % (by volume) Acetone and 90 % non-abrasive applicator; 10 % (by volume) Acetone and 90 %
(by volume) isopropyl alcohol (90 % - (by volume) isopropyl alcohol (90 % - 99 % strength) 99 % strength)
CAUTION CAUTION : This is a ammable mixture. : This is a ammable mixture.
Unless specied otherwise in this Unless specied otherwise in this service manual, lubrication service manual, lubrication
of contacts in not required. of contacts in not required.
2. After removing an electrical assembly equipped with ES 2. After removing an electrical assembly equipped with ES
devices, place the assembly on a conductive surface such as devices, place the assembly on a conductive surface such as
aluminum foil, to prevent electrostatic charge buildup or expo- aluminum foil, to prevent electrostatic charge buildup or expo-
sure of the assembly. sure of the assembly.
3. Use only a grounded-tip soldering iron 3. Use only a grounded-tip soldering iron to solder or unsolder to solder or unsolder
ES devices. ES devices.
4. Use only an anti-static type solder removal device. Some sol- 4. Use only an anti-static type solder removal device. Some sol-
der removal devices not classied as “anti-static” can generate der removal devices not classied as “anti-static” can generate
electrical charges sufcient to damage ES devices. electrical charges sufcient to damage ES devices.
5. Do not use freon-propelled chemicals. These can generate 5. Do not use freon-propelled chemicals. These can generate
electrical charges sufcient to damage ES devices. electrical charges sufcient to damage ES devices.
6. Do not remove a replacement ES 6. Do not remove a replacement ES device from its protective device from its protective
package until immediately before you are ready to install package until immediately before you are ready to install it. it.
(Most replacement ES devices are packaged with leads elec- (Most replacement ES devices are packaged with leads elec-
trically shorted together by conductive foam, aluminum foil or trically shorted together by conductive foam, aluminum foil or
comparable conductive material). comparable conductive material).
7. Immediately before removing the protective material from the 7. Immediately before removing the protective material from the
leads of a replacement ES device, touch the leads of a replacement ES device, touch the protective mate- protective mate-
rial to the chassis or circuit assembly into which the device will rial to the chassis or circuit assembly into which the device will
be installed. be installed.
CAUTION CAUTION : Be sure no power is : Be sure no power is applied to the chassis or cir- applied to the chassis or cir-
cuit, and observe all other safety precautions. cuit, and observe all other safety precautions.
8. Minimize bodily motions when handling unpackaged replace- 8. Minimize bodily motions when handling unpackaged replace-
ment ES devices. (Otherwise harmless motion such as the ment ES devices. (Otherwise harmless motion such as the
brushing together of your clot brushing together of your clot hes fabric or the lift hes fabric or the lift ing ing of your of your
foot from a carpeted oor can generate static electricity suf- foot from a carpeted oor can generate static electricity suf-
cient to damage an ES device.) cient to damage an ES device.)
General Soldering Guidelines General Soldering Guidelines
1. Use a grounded-tip, low-wattage soldering iron and 1. Use a grounded-tip, low-wattage soldering iron and appropri- appropri-
ate tip size and shape that will ate tip size and shape that will maintain tip temperature within maintain tip temperature within
the range or 500 ° the range or 500 ° F to 600 °F. F to 600 °F.
2. Use an appropriate gauge of 2. Use an appropriate gauge of RMA resin-core solder composed RMA resin-core solder composed
of 60 parts tin/40 parts lead. of 60 parts tin/40 parts lead.