The diagnostic method: one way to work every call, from the complaint to the options sheet
In one paragraph
Every call in this phase runs on one method: verify the complaint in the customer's words, isolate the circuit or system, run the cheapest test first (voltage, then continuity, then load), find the cause instead of the symptom, lay out an options ladder (repair, replace the section, replace the system) with a cost band, a permit path and a code trail for each rung, then document and communicate. The method is what makes a new contractor look like an experienced one, and it is also how the safety orders expect the work to be done: de-energize, lock and tag, test before touch, and treat energized work as a supervised exception.
The rule
Cal/OSHA's Electrical Safety Orders allow work on exposed energized parts only when responsible supervision has decided the work must be done energized, the people involved are instructed, and insulated gloves or tools, barriers and eye protection are used, with insulated gloves required above 250 volts to ground (8 CCR 2320.2(a)); before work on de-energized equipment the disconnecting means is locked open and tagged and stored energy is blocked (2320.4(a)). Federal OSHA states the same default: live parts are de-energized before work unless that creates a greater hazard or is infeasible, and testing is the recognized infeasibility (29 CFR 1910.333(a)(1)).
Why it matters
The customer is not buying a repair; they are buying the feeling that someone competent found the real problem and told them the truth about their choices. A fixed method produces that feeling every time, protects you from the two ways new contractors get hurt (touching something live and guessing wrong on a $4,000 job), and leaves a paper trail that matches the contract law in Phase 3.