Analysis of Fault-Location Behavior in Electronic Equipment

Two analyses of maintenance technicians' intermediate behavior in trouble-shooting electronic equipment are reported. In the first, 422 records of this behavior were analyzed to describe the characteristics of the process. It was found that technicians frequently accumulated sufficient symptom information from test points to isolate a malfunctioning stage or to identify a faulty component, before they recognized this fact. Typically, either they continued to make redundant or irrelevant checks before entering the correct stage or replacing the correct part, or they never did use the information and thus failed to solve the problem. Also, 71 per cent of the first replacements of components were incorrect. Evidently, searching for symptom information and interpretation of that information occur on two different behavioral levels, which are not necessarily closely coordinated.