HP Vectra VL800, Technical Reference Manual

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7
Tests and Error Messages
This chapter describes the firmware test sequences and error
messages, the pre-boot diagnostics error codes, the Power-On Self-Test
(POST) routines, which are contained in the computer’s ROM BIOS, the
error messages which can result, and the suggestions for corrective action.
Test Sequence and Error Messages
When the PC is turned on (pressing the ON/OFF button), the system
initiates the normal startup sequence which is composed of the following
steps:
• Basic pre-boot diagnostics
• BIOS launch
• POST phase
• Operating System boot phase
If any errors are detected during the startup sequence, the PC will not
necessarily come to a halt or ‘freeze’. However, some critical hardware
errors are fatal to the system and prevent the system from starting (for
example, ‘CPU Socket’ and ‘Power Supply’ are serious malfunctions that
prevent the system from working correctly).
Errors that are not critical are detected both during pre-boot diagnostics
and POST where the BIOS boot process returns an error code. Some errors
are only detected during POST sequence, and produce the same process.
Finally, while the PC is working, fan status and PC temperature can be
reported (for example, a fan error will be reported if a fan cable is not
connected). This type of error disappears as soon as the problem is fixed
(for example, the fan cable has been reconnected).
The diagnostic test are described below.