Visually inspect the wire for deterioration. If it shows signs of breakage or burned areas, it should be replaced. If the wire looks good, follow up with a conductivity test. Turn the system power off. Disconnect one lead to the coil (this might require a soldering iron) and connect one meter lead to each end of the coil. A null or low reading indicates continuity. A reading of high or infinite resistance indicates a lack of continuity. Replace the coil.
The following points summarize the main elements of this lesson:
Ohm's Law is the basic formula for power calculations.
There are two types of power: alternating current (AC) and direct current (DC).
A multimeter is used to measure volts, amps, continuity, and resistance.
A computer technician should be familiar with the various electronic components found on a power-supply circuit board.
In a new installation, a computer technician should never assume that the power supplied in the wall outlets is correct. Always test and be sure.
Be careful with large electrolytic capacitors. They can store electrical charges and must be discharged before it is safe to work with them.
Electrostatic Discharge (ESD)
This lesson discusses a phenomenon that can damage or ruin sensitive electronic equipment-electrostatic discharge (ESD), sometimes referred to as static electricity. Fortunately, it is one of the easiest things to protect against.
After this lesson, you will be able to:
Estimated lesson time: 15 minutes
Define ESD (electrostatic discharge).