During troubleshooting fluorescent and HID lighting fixtures, which component is replaced first?

• A. Ballast
• B. Wiring
• C. Lamp
• D. Fixture housing

Answer: (C)

When diagnosing fluorescent and HID lighting, the first thing you test is the lamp itself. Lamps have the shortest service life and fail most often, so swapping in a known-good lamp is the quickest and least expensive way to determine if the lamp is the cause. If the new lamp lights properly, the problem was the old lamp and the rest of the components aren’t likely the issue. If the issue persists after a lamp replacement, you can then move on to testing the ballast and the wiring. Wiring issues or a faulty ballast are less likely to be resolved by a simple swap and often require more involved checks, while the fixture housing doesn’t affect electrical operation.