How to Test Capacitor with Analog Multimeter, Ohm Meter

Knowing the condition of the transistor we can do if we understand the basic characteristics and working principle of a transistor as a switch. As well as determining the foot transistor, in knowing the transistor condition we also have to understand the characteristics of the transistor legs. Basic characteristics that must be known to determine the condition of the transistors in the transistor are as follows:

1. For the NPN transistor, the base has a relationship collector forward from the base to the emitter to the base and from as well as a reverse relationship to the position of vice versa.
   
2. For PNP transistor, the base has a reverse relationship from the base to collector and from the emitter to the base as well as the relationship forward for the position of vice versa.
   
3. In the general transistor between the collector and emitter legs have infinite resistance when the base does not get bias voltage.
   
4. Then at the base given the bias between the collector to the emitter will have a low resistance to the relationship forward to transistor NPN and PNP transistors for the reverse relationship.
   
5. To determine the condition of the transistor with a multimeter we have settings multimeter on OHM meter position with x10 or x100 scale to test the base and then to test the relationship on a scale collector emitter x10k.

How to test standard transistor condition?

1. Test base for an NPN transistor, connect the base with black and red probe probe to the collector and emitter. At the second position to move the needle multimeter should designate the resistance value of hundreds to tens of Ohm (not 0 Ohm). Then the reverse position, the base is connected to the probe of red then black probe to the collector and emitter. In both these positions multimeter needle does not move or appoint an infinite resistance.
   
2. Test base for PNP transistor, connect the base with the red probe and black probe to the collector and emitter. At the second position to move the needle multimeter should designate the resistance value of hundreds to tens of Ohm (not 0 Ohm). Then the reverse position, the base is connected to the probe black then red probe to the collector and emitter. In both these positions multimeter needle does not move or appoint an infinite resistance.
   
3. Test the transistor as a switch for an NPN transistor, connect the black probe to the collector, putting our fingers to the collector and the red probe to the emitter leg without finger touched or our bodies while the base is left unconnected, the position of the needle on the multimeter should be silent or pointing to infinite resistance. Then touch the base with your finger, the finger touched the base position of the transistor gets base bias and multimeter needle should move points to a low resistance value.
   
4. Test the transistor as a switch for the PNP transistor, connect the black probe to the emitter leg, putting a finger to toe red probe to the emitter and the collector without fingers or body touched us while the base is left unconnected, the position of the needle on the multimeter should be silent or pointing to infinite resistance. Then touch the base with your finger, the finger touched the base position of the transistor gets base bias and multimeter needle should move points to a low resistance value.

When testing the above terms and conditions are not met, the transistor can be said to be in worse condition or damaged.

Testing Transistor with Internal Dumper

For the transistor with internal dumper, the differences of transistor tests are located at:

1. Test the base to the emitter showed the same value although reversed and multimeter probes point to dozens Ohm resistance value (not 0 Ohm).
2. Test the collector emitter resistance, black probe on the emitter leg and the red probe on the collector, the position of the needle on the multimeter should point to the value of hundreds of Ohm (not 0 Ohm). Later in the opposite position, the red probe on the emitter leg and the black probe on the collector needle pointing to the multimeter be silent or infinite value.
3. Then test the transistor as a switch, ie by putting the black probe to the foot collector by gluing fingers and put the red probe to the emitter leg without being connected to the fingers and our bodies and the base is not connected, the position of the needle on the multimeter be silent or pointing infinite resistance. Then touch the base with your fingers to give biased bases, then pointed to the value of hundreds of Ohm multimeter (not 0 Ohm).

If these conditions are met then the transistor is in good condition and if not met, then the transistor in a damaged condition.