Learning the most efficient methods of troubleshooting not only saves the technician’s time, but also the customer’s money. Systematic troubleshooting using the symptom/cause method is a quick and efficient way a service technician can solve even the toughest of service calls. Good systematic troubleshooting skills and techniques are a win-win situation for both customer and technician.

Consider the following example of systematic troubleshooting that incorporates the symptom/cause method. The service call is for no cooling in a medium temperature reach-in cooler in a small town variety store. Figure 1 (top) illustrates the single-phase, R-134a capacitor start/capacitor run (CSCR) refrigeration compressor motor and starting relay circuit section of an electrical schematic diagram for the cooler. Notice in this circuit that the compressor’s run winding has been burnt open from a motor overheating problem.