The most common failure mode is an electrical short between the main terminals, although a Triac can fail in a half-wave condition. It is possible, but not probable, that the resulting short- circuit current could melt the internal parts of the device which could result in an open circuit.
How do you know if a TRIAC is bad?
The lamp must glow indicating the switching ON of triac. When you release the push button, you can see the lamp extinguishing. If the above tests are positive you can assume that the triac is healthy.
How do you troubleshoot a TRIAC?
Step by step Procedure to test the triac:
- Keep the digital multimeter into Ohmmeter mode.
- Using a junction diode determine which ohmmeter lead is positive and which is negative. ...
- Connect the positive lead of Ohmmeter to MT2 and the negative lead to MT1. ...
- Using a jumper lead connect the Gate of the Triac to MT2.
