1. A diagnostic system for identifying a component that has failed, the diagnostic system comprising: an interface for receiving input relating to observed symptoms indicative of a failed component; a processing element for correlating the input relating to the observed symptoms with a plurality of suspect components that are each capable of causing the observed symptoms upon failure, said processing element capable of prioritizing the plurality of suspect components based upon a relative likelihood that the respective suspect components caused the observed symptoms, said processing element also capable of identifying at least one test to be performed in order to refine the prioritization of the plurality of suspect components; and a display for presenting a prioritized listing of the plurality of suspect components and an indication of the at least one test to be performed in order to refine the prioritization of the plurality of suspect components.