Working electronic components are crucial to operating virtually any electronic device. Components such as resistors, capacitors and transistors create circuits that allow TVs, stereos, cell phones and laptops to work properly. Each component has a specific role in a circuit. Resistors limit current. Capacitors store charge. Transistors amplify an electrical signal.
Repairing an electronic device begins with testing these electronic components through a multimeter. Multimeters can measure resistance and voltage. They can test devices powered by either AC or DC voltages and work in or out of circuit. You can use a standard multimeter or if you are looking for a quick and easy way to test components, take a look at the Excelta TM-500 IntelliTweezer or the lower cost solution Aven 18910 Quick Test Auto-Scanning Tweezers.
Multimeters are simple to use because of their readable display and multitude of measuring functions. A handheld multimeter is low cost, easy to use and gives accurate readings. Using one to test your electronic components lets you determine if they need to be repaired or replaced.
When using a multimeter to check electrical components, following these steps to obtain an accurate reading:
1. Switch on the multimeter. Turn the knob to the resistance setting marked by the symbol for the Greek letter Omega. Your knob setting should match the resistor value. If the value is unknown, start with the lowest setting and increase in gradual increments as you test the resistor.
2. Place a multimeter probe on each resistor lead. Record the resistance. Switch probes and note the resistance again.
3. Place the multimeter probes on other components leads. This can include diodes, capacitors and photocells. Measure the resistance using the same method as with the resistor. Photocells should be tested twice – near a light source and far away from that same light source.
Expect varying resistance measurements for certain electrical components. With diodes, you will experience a small amount of resistance only when the probes are placed one way but not the other. Capacitor resistance, on the other hand, should be almost limitless or else it is damaged.