3, before the discovery and confirmation of defective parts TV faulty electrical test , you can use visual , olfactory and tactile simple checks. To see whether the component has been burnt or burning characterization , such as sealing wax is melted capacitor siltation ; resistance charred discoloration ; smell can check transformers, chokes , resistors, etc. without overheating caused abnormal taste ; Touch Case You can check the overheating components. Typically use a multimeter for voltage testing and conducting experiments to discover and confirm defective parts . When conducting the experiment performed after the power is turned off from the circuit structure, the result will be affected by other components and can not indicate an accurate value , so as to be disengaged from one of the contact member , and then measured.

In addition, some parts of the state due to a fault ( eg capacitor decreases or leakage , etc. ) can not be determined with a multimeter , should be replaced with a genuine try, and join the authentic or capacitors, look for any changes in symptoms . As bad capacitor insulation or shorted detection need to end disengaged. When changing element, the element should be as incumbent and components used in the same machine , and use good . Some circuit component parameters if they are different , it does not prevent the work , it is important is the need to fully understand how its circuit.

 

Two points and techniques for fault check

1, on the inspection method of the circuit elements constituting the circuit elements : the transistor , resistors, coils, capacitors, etc. , of which circuits are each composed of several elements . Once you master its methods, early detection can check the faulty component . Inspection methods: For l, c, r , it should be known to each component in the exchange (ac) circuit and current (dc) circuit is how it works. The capacitor can be seen in the ac circuit the AC signal flowing through the conductor , the right and left ends of the dc circuit are not connected together , no current flows , it can be regarded as an insulator . Thus capacitor with a multimeter continuity test , is the woman should indicate the open state , if the instructions conduction state , then Pat broken. Each power stage transistors if not coupled with normal voltage will not work. Pnp and npn type transistors have their voltage relationship is reversed . To make the transistor work , the base - emitter forward bias voltage to be applied . For an ordinary amplifier circuit, the voltage of the silicon tube is 0.6 to 0.7 volts , germanium tube should be 0.2 to 0.3 volts.

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