Compaq AP500 manual Power-On Self-Test Post, 2Diagnostic Tools

4-2Diagnostic Tools

Power-On Self-Test (POST)

POST is a series of diagnostic tests that run automatically when the system is turned on. After the computer is turned on, POST checks the following assemblies to make sure the computer system is functioning properly:

■Keyboard

■Memory

■Graphics controller

■Diskette drives

■IDE CD-ROM drive

■Hard drives

■Processors

■Controllers

POST also detects the type of SCSI mass storage devices installed in the workstation.

NOTE: If the Power-On Password is set, a key icon ( ) displays 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 in the next section.