Chapter 2. Theory Of Operation; Introduction - HP 9020 Service Manual

Theory of Operation
Chapter
2
Introduction
This chapter describes the theory of operation of the computer. Included are functional descriptions
of each section of the computer with more detailed description where appropriate. Figure 2-1 is a
functional block diagram of the computer, showing all the functional modules described in this
chapter. Figure 2-2 shows how the computer modules are interconnected. It provides cabling
information, connector designations, and number of pins per connector.
Some of the functional units described in this chapter are standard in the computer, and others are
optional. Familiarize yourself with the particular computer being serviced to know which sections of
this chapter are applicable and which are not.
The functional units described in this chapter are as follows:
• Power supply assembly
• Processor stack
• Keyboard
• Display
• Thermal printer
• Mass storage (flexible and fixed disc drives)
• Motherboard
• 110 backplane
2-1