4-2
Compaq Professional Workstation AP550 Maintenance and Service Guide
Power-On Self-Test (POST)
POST is a series of diagnostic tests that runs automatically when the system is turned on. After
the computer is turned on, POST checks the following assemblies to make sure that the
computer system is functioning properly:
■
Keyboard
■
RIMMs
■
Graphics controller
■
Diskette drives
■
IDE/CD-ROM drive
■
Hard drives
■
Processor
■
Controllers
POST also detects the type of SCSI mass storage devices that are installed in the workstation.
NOTE:
If the Power-On Password is set, a key icon (
) appears on the screen while POST is running.
You will need to enter the password before continuing. See Chapter 5 for information on deleting or
bypassing the Power-On Password.
If POST finds an error in the system, an audible and/or visual message occurs. For explanations
of the error codes and a recommended course of action, see Table 4-1.
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