How to Test Diode(Find bad diode)

Introduction:
               The most common function of a diode is to allow an electric current to pass in any one direction. another application is rectifier(convert Alternating current AC to Direct current DC) at power supply, including extraction of modulation from radio signals in radio receivers. it is a two-terminal semiconducter device, those pins are labeled anode(A) and cathode(K). now, i will show how to check diode using multimeter.

method 1: using multimeter

• First turn ON digital multimeter and select diode mode.
• Connect the test leads to the diode terminals. Keep test leads connected for a few seconds at forward connection.
• Read the measurement displayed. If the diode value is within the measurement range, the multimeter will display the diode value.
• displayed multimeter value is from 0 above 150, the diode is good.
• displayed multimeter value is 0 or .0L, the diode is bad.

• Connect the test leads to the diode terminals. Keep test leads connected for a few seconds at reverse connection.
• Read the measurement displayed. If the diode value is within the measurement range, the multimeter will display the diode value.
• displayed multimeter value is 0 or .0L, the diode is good.

• First turn ON digital multimeter and select continuity mode.

• Connect the test leads to the diode terminals. Keep test leads connected for a few seconds at reverse connection or forward connection. 
• If the multimeter buzzer will ON, the diode is bad.
• else multimeter buzzer will OFF, the diode is good.

method 2: using AC power + oscilloscope

• A reverse connection can be made out of just a single diode. If an AC signal, like a sine wave for example, is sent through a diode any negative component to the signal is clipped out, the diode is good.

• A forward connection can be made out of just a single diode. If an AC signal, like a sine wave for example, is sent through a diode any negative component to the signal is clipped out, the diode is good.