How to Test Electronic Parts

Almost everyone on the planet today use electronic gadgets. In all these devices, an electrical circuit can and will go bad. Unless you are prone to throwing money away, there are ways you can check these electronics and fix the majority of your problems. 

• When testing resistors keep in mind that their function is to “resist” the flow of electrical current. This resistance is measured in ohms. The higher the resistance the lower the current is going to be. They are color-coded. The formula is as follows. Start at the end opposite the gold band going from left to right. Multiply the number by the brown band times the number with the black band and you should have 10. Multiply that times the red band and that will be your answer. Check it with the ohmmeter and that is what your reading should be.


• To test capacitors place your multimeter on Rx10 or the Rx1k scale. Remember capacitors are like little batteries as in they store energy. Place the testers negative probe to the capacitors positive terminal and the positive to the negative one. For electrolytic capacitors, it is most likely defective if the meter rests on zero and remains stationary indicating it is defective.


• Diode testing requires you to set the multimeter to any of the resistance positions (x1, x10, x1K or 10K ohm’s) and put the negative probe to the cathode and the positive one to the anode. This should produce very little or no deflection. Reverse the probes and you should see deflecting towards zero.


• Using the ohmmeter test your transistors. You do this when you wish to check resistance across the transistor emitter and the collector. PNP or NPN makes no difference as the probes may be connected either way. A transistor that is working properly will read above 1000 ohms.