Fault Isolation Using Power On Self Test

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When the computer is first powered up, it automatically performs a Power On Self Test (POST) that checks the notebook's central hardware and memory functions. During POST (which lasts for a few seconds), the display shows copyright and version number information.

Note: Some procedures in this paragraph require you to use keystroke sequences, such as Ctrl-Alt-Del. To execute a keystroke sequence such as this, you must press all three keys simultaneously.

5.3.3.1 POST Error Messages

Upon successful completion of Power On Self Test, the computer automatically loads its operating system and other built-in utilities. If POST fails to complete successfully, the display shows one of the error messages described in Table 5-2.

Note: In the event of a hardware problem that affects the display, the Notebook also communicates errors via a series of beeps. The interpretation of the beep codes is provided in Table 5-3.

Note: Refer to Appendix C for POST BIOS listing.

Message

Possible Cause

Action

Diskette drive A failure

The drive failed or is missing.

Check the drive to determine the problem.

Diskette read failure - press F1 to retry boot, F2 for SETUP utility

The disk is either not formatted or is defective.

Replace the disk with a bootable disk and retry.

Display adapter failed, using alternate

The primary video adapter failed.

Check the primary video adapter.

Gate A20 failure

The keyboard controller is not accepting command, specifically, the enable and disable A20 command.

Check the keyboard controller and system board. Turn the power off, then back on again. If the problem persists contact qualified service personnel .

Fixed disk configuration error

The specified configuration is not supported or doesn't match the actual hardware installed.

Correct the fixed diskette configuration.

Fixed disk controller failure

The fixed diskette may be defective.

Try rebooting. If that doesn't work, replace the fixed diskette.

Fixed disk read failure-press F1 to retry boot, F2 for SETUP utility

The fixed diskette may be configured incorrectly or is defective.

Check the drive type selected in Setup. Try rebooting. If that does not work, replace the fixed diskette.

Pointer device failure

The PS/2-style mouse failed.

Try rebooting. If problem persists, check the mouse, cable and connector.

Message

Possible Cause

Action

No boot device available -press F1 to retry boot, F2 for SETUP utility

Either disk drive A:, the fixed diskette, or both the disk and fixed diskette are defective.

Try rebooting. If the problem persists, replace the disk or the fixed diskette.

No boot sector on fixed disk - press F1 to retry boot, F2 for SETUP utility

The C: drive is not formatted or is not bootable.

Format the C: drive and make it bootable.

Not a boot diskette - press F1 to retry boot, F2 for SETUP utility

The disk in drive A: is not formatted as a bootable disk.

Replace the disk with a bootable disk and try rebooting.

No timer tick interrupt

The timer chip has failed.

Check the system board. Turn the power off, then back on again. If the problem persists, contact qualified service personnel.

Shutdown failure

Either the keyboard controller is not accepting the reset command or the associated reset logic has failed.

Check the keyboard controller and system board. Turn the power off, then back on again. If the problem persists, contact qualified service personnel.

Time of day not set - run SETUP program

Real time clock not set.

Run the Setup utility.

Timer 2 failure

The timer chip has failed.

Check the system board. Turn the power off, then back on again. If the problem persists, contact qualified service personnel.

F2 to enter ROM-based SETUP

Invalid configuration information must be changed.

You must run the Setup utility and correct configuration information.

Invalid configuration information - please run SETUP

Display adapter is configured incorrectly.

Memory size is incorrect. Wrong number of disk drives. Other configuration errors.

Run the Setup utility.

Table

5-2 POST Error Messages (continued)

Message

Possible Cause

Action

Keyboard clock line failure

The keyboard, the keyboard cable connection, or the keyboard controller is defective.

Make sure the keyboard cable and keyboard are connected properly. Check the keyboard controller and the system board. Turn the power off, then back on again. If the problem persists, contact qualified service personnel.

Keyboard data line failure

The keyboard controller firmware has failed.

Check the keyboard controller and system board. Turn the power off, then back on again. If the problem persists, contact qualified service personnel.

Keyboard stuck key failure

A key is jammed.

Locate the jammed key and fix it. Make sure the keyboard cable and keyboard are connected properly. Turn the power off, then back on again. If the problem persists, contact qualified service personnel.

Memory failure at hex-value, read hex-value, expecting hex-value

Circuitry associated with the memory chips has failed.

Turn the power off, then back on again. If the problem persists, contact qualified service personnel.

Unexpected interrupt in protected mode

Hardware interrupt or NMI occurred while in protected mode.

Check the timer chip or the interrupt controller on the system board.

Real time clock failure

The RTC or battery failed.

Run Setup and turn the power off and on. If the problem persists, replace the RTC battery. If the problem remains, contact qualified service personnel.

5.3.3.2 POST Beep Error Messages

In the event of a hardware problem that affects the display, the Notebook also communicates errors via a series of beeps. These codes may be heard over the system's speaker as a series of beeps (long and short duration). The interpretation of the beep codes is provided in Table 5-3.

To recover from a self test error, try cycling power to the computer. Also, press Ctrl-Alt-Esc to ensure that the Setup configuration is correct. In general, most of the failures are associated with the Upper and Lower Electronics Boards and may require board removal/replacement.

Try running PC-Doctor (Paragraph 5.5) if possible to verify the source of problem.

Table 5-3 Self Test Beep Messages

Beep Code

Description

VGA Failures

1 Long, 2 Short

Horizontal Retrace Failed

1 Long, 3 Short

DAC Test Failed

1 Long, 4 Short

Monitor Sense Failed

1 Long, Five Short

Vertical Retrace Failed

1 Long, 6 Short

DVideo Memory Test Failed

System Failures

2 Short

Battery Low 1

3 Short

Battery Low 2

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