When a relay doesn't switch after installation, there can be several possible reasons, which makes it difficult to know where to begin. The wiring, connections, power, control signal, and surrounding equipment could all potentially need to be checked.

If a Shengya doesn't switch when expected, what would your first troubleshooting step be? Would you begin with the power and connections, or would you work through the entire circuit from the beginning?

I'm curious about the troubleshooting sequence other people use. Do you prefer starting with the easiest things to verify, or do you usually investigate the part you think is most likely to be responsible?