LED failures follow a bathtub curve. The leftmost section — infant mortality — is dominated by manufacturing defects: cold solder joints, marginal driver components, hairline solder cracks. These fail within the first 2–10 hours.
A 2–4 hour aging test catches almost all infant-mortality units. Without it, those units ship to your warehouse, then to your customer, then become RMAs at the worst possible time.
Factories that skip 100% aging often run a sample-only burn-in (e.g. 5% of the batch). This catches systemic problems, but it misses unit-level defects.
At LED Lightning every fixture runs a minimum 2-hour aging test under load before packing. For project-grade fixtures, the burn-in extends to 4 hours. Yes, it adds cost. But it keeps RMA rates below 0.4%.
