Product Safety Notices; General Servicing Precautions - Samsung DE40A Service Manual

1. Precautions

1-1-4. Product Safety Notices

Some electrical and mechanical parts have special safetyrelated characteristics which are often not evident from visual
inspection. The protection they give may not be obtained by replacing them with components rated for higher voltage,
wattage, etc. Parts that have special safety characteristics are identified by
replacement that does not have the same safety characteristics as the recommended replacement part might create
shock, fire and/or other hazards. Product safety is under review continuously and new instructions are issued whenever
appropriate.
1-2. Servicing Precautions
Note: If unforeseen circumstances create conflict between the following servicing precautions and any of the safety
precautions, always follow the safety precautions.

1-2-1. General Servicing Precautions

1. Always unplug the unit's AC power cord from the AC power source and disconnect the DC Power Jack before attempting
to: (a) remove or reinstall any component or assembly, (b) disconnect PCB plugs or connectors, (c) connect a test
component in parallel with an electrolytic capacitor.
2. Some components are raised above the printed circuit board for safety. An insulation tube or tape is sometimes used.
The internal wiring is sometimes clamped to prevent contact with thermally hot components. Reinstall all such elements
to their original position.
3. After servicing, always check that the screws, components and wiring have been correctly reinstalled. Make sure that the
area around the serviced part has not been damaged.
4. Check the insulation between the blades of the AC plug and accessible conductive parts (examples: metal panels, input
terminals and earphone jacks).
5. Insulation Checking Procedure: Disconnect the power cord from the AC source and turn the power switch ON.
Connect an insulation resistance meter (500 V) to theblades of the AC plug.
The insulation resistance between each blade of the AC plug and accessible conductive parts (see above) should be
greater than 1 megohm.
6. Always connect a test instrument's ground lead to the instrument chassis ground before connecting the positive lead;
always remove the instrument's ground lead last.
1-2
An electrolytic capacitor installed with the wrong polarity might explode.
Before servicing units covered by this service manual, read and follow the Safety
Precautions section of this manual.
on schematics and parts lists. A substitute