You cannot fix what you cannot see or measure. The fundamental electrical troubleshooting toolkit goes beyond a screwdriver and pliers. Here is what you need:
Use schematics to isolate which part of the circuit is failing (e.g., the power source, the load, or the control circuit) as detailed by Landmark Electric . fundamental electrical troubleshooting pdf
No electrical guide is complete without a stark warning. Electricity is silent, invisible, and lethal. Before you touch a single wire or probe a terminal, internalize these five rules: You cannot fix what you cannot see or measure