Which step involves testing to isolate the problem?

• A. Listing Faulty Functions
• B. Localizing the Faulty Function
• C. Localizing Trouble to the Circuit
• D. Failure Analysis

Answer: (C)

Testing to isolate a fault means using careful checks to narrow down where the problem lives. Localizing trouble to the circuit is the step that pinpoints the fault inside the circuit boundaries, rather than outside it or in a specific function. By running measurements and tests at logical points—such as tracing the signal from input toward output and verifying continuity and operation within the circuit—you determine that the issue is contained within the circuit itself. This focus lets you zero in on the particular subcircuit or component causing the fault, which is the essential next move for effective repair.