Power-On Self-Test

Note

If Quiet Boot is enabled in BIOS Setup (the default setting), press ESC during boot to see POST messages.

The POST (Power-On Self-Test) is a series of initialization routines and diagnostic tests that the system BIOS runs when the computer boots. The system BIOS will not boot the operating system if system memory, the CPU, DMA, or the interrupt controller fails the POST diagnostic tests. POST progress is indicated by a sequence of codes, and error messages are displayed if possible.

You should not necessarily interpret the failure of one or more POST tests as a hardware, software, or firmware failure. First, confirm the failure by performing a “clean” boot:

Remove all accessories, including SDRAM modules, floppy drive, port replicator, PC Cards, printer, external monitor, pointing device, and keyboard.

Provide “clean” ac power—no auto adapter or unusual ac adapter configuration.

Press the system-off switch to start the computer from a known state.

If the computer fails to boot with a clean boot, it requires repair. If an error message appears, confirm the problem using other diagnostic tools. Not all POST messages indicate a hardware, software, or firmware failure—some messages are for information only.

If the BIOS detects a terminal error condition, it halts POST after issuing a terminal error beep code (see the following table). The beep code indicates the POST routine in which the terminal error occurred.

Table 3-4. POST Terminal-Error Beep Codes

Beep Codes*

POST Description

1

One short beep before boot.

1-2

Search for option ROMs.

1-2-2-3

BIOS ROM checksum.

1-3-1-1

Test DRAM refresh.

1-3-1-3

Test 8742 Keyboard Controller (part of power supply PCA).

1-3-4-1

RAM failure on address line xxxx.

1-3-4-3

RAM failure on data bits xxxx of low byte of memory bus.

1-4-1-1

RAM failure on data bits xxxx of high byte of memory bus.

2-1-2-3

Check ROM copyright notice.

2-2-3-1

Test for unexpected interrupts.

1 long-2 short

Improper video configuration (check display DIP switches, replace display

 

interface PCA) or external ROM checksum failure.

1 long-5 short

Display DIP switches and EEPROM settings do not match (check DIP switch

 

settings, reprogram EEPROM).

*Up to four groups of short beeps, except as noted.

HP OmniBook 6000

Troubleshooting and Diagnostics 3-21

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HP Book 6000 manual Power-On Self-Test, Post Terminal-Error Beep Codes, Beep Codes Post Description