Define Your Symptoms When a PC breaks down, the cause might be as simple as a loose wire or connector, or as complicated as an IC or sub-assembly failure. Before you open your toolbox, you must have a firm understanding of all the symptoms. Think about the symptoms carefully—for example - Is the disk or tape inserted properly - Is the power or activity LED lit - Does this problem occur only when the computer is tapped or moved By recognizing and understanding your symptoms, it can be much easier to trace a problem to the appropriate assembly or component. Take the time to write down as many symptoms as you can. This note-taking might seem tedious now, but once you have begun your repair, a written record of symptoms and circumstances will help to keep you focused on the task at hand. It will also help to jog your memory if you must explain the symptoms to someone else at a later date. As a professional troubleshooter, you must often log problems or otherwise document your activities anyway.