Service Manual
Model No.: LET40T3
5
a. Removing or reinstalling any component, circuit board module or any other receiver
assembly.
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 part substitution or incorrect polarity installation of electrolytic capacitors
may result in an explosion hazard.
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. Do not spray chemicals on or near this receiver or any of its assemblies.
4. 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 non-
abrasive 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.
Capacitors may result in an explosion hazard.
5. Do not defeat any plug/socket B+ voltage interlocks with which receivers covered by this
service manual might be equipped.
6. 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.
7. 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. Capacitors may result in an explosion
hazard.
8. 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.
9. Remove the antenna terminal on TV and turn on the TV.
10. Insulation resistance between the cord plug terminals and the eternal exposure metal should
be more than Mohm by using the 500V insulation resistance meter.
11. If the insulation resistance is less than M ohm, the inspection repair should be required.
If you have not the 500V insulation resistance meter, use a Tester. External exposure metal:
Antenna terminal Headphone jack.
12. Use only a grounded-tip soldering iron to solder or unsolder ES devices.
