Individual Functional Block Diagrams

Overall Functional Block Diagrams Overall functional block diagrams will show the functional areas of the computer and the supporting functions, such as power, cooling, and control of the computer. They will also show the types of signals exchanged between the functional areas and the supporting functions and the direction of signal flow. Figure 2-1 is an example of an overall functional block diagram of a computer. Overall functional block diagrams are very useful when you perform corrective maintenance. After you have identified and elaborated on a problem, you can use the overall block diagram for the “listing of probable faulty functions.” This will help you in your next step in the troubleshooting process— “localizing the faulty function.” The overall functional block diagram can help you stay in the right area when troubleshooting. Individual Functional Block Diagrams Once an overall description has been presented, the technical manual will give a general description of each functional area separately. These will include the major functional areas (CPU, I/O, and memory); the supporting functional areas (power supply and any special cooling requirements); and control of the computer (maintenance console/panel or display control unit and remote console/panel). When each functional area is described individually, an accompanying functional block diagram of that area will follow. Individual functional block diagrams can help you in your troubleshooting once you have “localized the faulty function.” They provide a more detailed analysis of how that specific area of the computer operates. See figure 2-2 as an example of an individual functional block diagram of a CPU. FUNCTIONAL LAYOUTS OF COMPUTERS Functional layouts will show the major functional areas of the computer—CPU, I/O, and memory. Figure 2-3 is an example of an individual functional layout for a basic single cabinet configuration. Systems that use a multiple configuration with more than one computer will also be depicted using an Figure 2-1.—Example of an overall functional block diagram. 2-2