Chapter 4
System Troubleshooting
This chapter provides instructions on how to troubleshoot system hardware problems.
Hardware Diagnostic Procedure
Please refer to generic troubleshooting guide for troubleshooting information relating to following topics:
q
q Undetermined Problems
Power-On Self-Test (POST)
Each time you turn on the system, the
The
The main components on the main board that must be diagnosed and/or initialized by POST to ensure system functionality are as follows:
qMicroprocessor with
q Interrupt system
q Three programmable timers q ROM subsystem
q RAM subsystem
q CMOS RAM subsystem and real time clock/calendar with battery backup q Onboard parallel interface controller
q Embedded hard disk interface and one diskette drive interface q Keyboard and auxiliary device controllers
q 1.44M floppy controller q I/O ports
q One parallel port
q One
qOne
NOTE: When Post executes a task, it uses a series of preset numbers called check points to belatched atport 80h, indicating the stages it is currently running. This latch can be read and shown on a debug board.The following table describes the BIOS common tasks carried out by POST. Each task is denoted by an unique check point number. For other unique check point numbers that are not listed in the table, refer to the corresponding product service guide.
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