Making conventional troubleshooting charts uncharacteristically effective

The three- or four-column trouble chart seems likely to be around for a while, despite promising new developments. A great deal can be done to improve this venerable device while we await the newer techniques. Admitting that most troubleshooting data are hypothetical — “written backward” circuit description — this paper proposes means of progressing from this state of affairs to satisfactory trouble analyses. Among such means are: using the “backward” description to develop a family of major trouble symptoms; breaking down these troubles into smaller indications that point to very particular faults, rather than general areas (a broken wire or blown fuse instead of “open circuit”) using early field-gathered reports to flesh out the hypothetical data; and arranging trouble data to fit the real — not the supposed — needs and technical level of the user by ascertaining his actual training and looking at the problem with the eye of the mechanic-technician rather than that of the engineer-analyst.