After verifying that power is supplied, what is the next step in diagnosing a malfunctioning machine?

• A. Verify basic operation conditions.
• B. Inspect lubrication.
• C. Check safety interlocks.
• D. Replace parts.

Answer: (A)

After power is verified, the next step is to make sure the machine is actually in a state to operate. This means checking basic operation conditions: control settings match the task, the correct materials or parts are in place, start and run controls are set properly, and any safety or environmental prerequisites are satisfied. If something essential is off—such as a wrong setting, missing material, or an incorrect setup—the machine can’t run correctly even though power is present, and you’d be chasing symptoms tied to setup rather than a true fault in components. Lubrication checks and safety interlocks are important, but they’re more specific checks that come after establishing that the machine is supposed to operate under the current setup. Replacing parts isn’t appropriate yet, since the goal is to diagnose based on actual conditions rather than swap components blindly.