Case study of no fault founds in household appliances

Abstract

In recent years, some obvious fault problems have been solved gradually with the continuous development of reliability engineering technologies, whereas the no fault found (NFF) phenomenon remains a big obstacle that troubles various manufacturers. Especially in the household appliance industry, NFF accounts for about 30–70% of the returned faulty products. Some electronic product manufacturers just ignore customers’ complaints of intermittent failure or the NFF phenomenon during retesting which may indicate defects in the products and simply attribute the problems as maintenance engineers’ misjudgment. Consequently, they rather lose the opportunity of improving product reliability. This paper reviews the NFF phenomenon commonly occurred in household appliances, with in-depth analysis on the failure modes and mechanisms. Based on failure physics, a few solutions to the NFF problems are also suggested, which can reduce substantially the NFF rate by approximately 50%.