Abstract Failure analysis of electronic components is almost always destructive, and there’s no going back once a destructive step is performed. Or, that’s the way it used to be, before the development of some of the more sophisticated nondestructive techniques such as computed tomography (CT). This paper presents a case study of an optocoupler, the suspected failure of which could not be confirmed until the last day of the month-long analysis, when the cause of failure was conclusively determined by a CT model captured weeks earlier.