Precautions for replacing capacitors(1)

         Fixed capacitance is prone to fault phenomena such as leakage, short circuit, open circuit, inadequate contact of the internal lead of the capacitor (the connection between the pole and the lead) and so on. Especially the electrolytic capacitance, its failure rate is much higher than other types of capacitors. Faults of electrolytic capacitance include leakage, reduction of capacity, breakdown, leakage of electrolyte and so on. If the capacitance is damaged, the original type shall be used. However, there are a wide variety of capacitors, if not the same type should be substituted.

The precautions for substitution are as follows:

The nominal value of the substitute capacitance can float ±10% on the basis of the nominal value of the original capacitance, and the range of floating can be larger for the power supply filter capacitance, bypass capacitance and so on. However, the capacitance of some circuits must be changed according to the original nominal value, otherwise it will cause the circuit to work out of ordering. If the resonant circuit, time constant circuit capacitance must be replaced by the original nominal value. If the coupling capacitance of the TV set and the cathode of the picture tube is damaged, the capacitance must be replaced by the original nominal value, otherwise, the image quality will be affected.