The Process of Fault diagnosis The Universal Troubleshooting Process Regardless of how complex your particular computer or peripheral device might be, a dependable troubleshooting procedure can be broken down into four basic steps (Fig. 4-1): define your symptoms, identify and isolate the potential source (or location) of your problem, replace the suspected sub-assembly, and retest the unit thoroughly to be sure that you have solved the problem. If you have not solved the problem, start again from Step #1. This is a universal procedure that you can apply to any sort of troubleshooting—not just for personal computer equipment.