Electronic Element Fault Characteristics

Though there are many electronic components in electrical equipment, their faults have follow certain rules.

The characteristics of the resistance damage

The most number of components in electrical equipment is resistance, but not the highest damage rate components. Resistance to the most common damage is open circuit. Commonly used resistances are carbon resister, metal film resistors, wire-wound resistor and insurance resistor. The damage characteristics are as follows: first, low resistance (100Ω below) and high resistance (100 k Ω above) damage rate is higher, resistance among hundreds of ohm (such as dozens of to thousands of ohm) has little damage; Second is the low resistance damage. It is often dark when burned, it’s easy to find. While high values resistance has few traces damage. Wire wound resistor is generally used as large current limit, resistance value is not big. Cylindrical wire wound resistor when dark or burn out some surface skin, crack, some blasting no traces. Cement resistance would be black or surface shell crack when burned, or some have no visible marks. Insurance resistance would never be black when damaged, but its surface may burn out one piece or have no traces. According to the above characteristics, we can quickly identify the resistance damage.

The characteristics of electrolytic capacitors damage

Capacitors in electrical equipment has large amount of usage, thus the failure rate is relatively high. Electrolytic damage has the following kinds of performance: one is completely lost the capacity or capacity became smaller; the second is it has mild or severe leakage; The third is it both lost capacity or capacity became smaller and has leakage. Search the damaged electrolytic capacitors methods are:

• Watch: some capacitor leakage, the circuit board surface or even appearance will be soiled, this kind of capacitance absolutely can’t use anymore; Some capacitance will plump up, this one also can not be used anymore.
• Touch: after startup some leakage serious electrolytic capacitors will fever, use your finger to touch it is very hot, this capacitance must be replaced;
• Electrolytic capacitor internal has electrolyte, long time baking will make electrolyte dry, leading to the capacity reducing, so we should focus on checking heat sink and high power components nearby capacitance.

The characteristics of integrated circuit damage

Integrated circuit structure is complex, and it has many functions, any parts of damage can not work normally. The damage of the integrated circuit is as follows: thoroughly damage and bad thermal stability. When it is completely damaged, it can be removed and compared with the normal integrated circuit to find the abnormal. To the IC which has the low thermal stability, we can use absolute alcohol to cool the IC. Usually we had to use new IC to replace it.