Power-On Self-Test

The POST (Power-On Self-Test) is a series of initialization routines and diagnostic tests that the system BIOS runs when the notebook boots. The system BIOS will not boot the operating system if system memory, the CPU, DMA, or 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. 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.

First, confirm the failure by performing a “clean” boot, as described below: If the notebook fails to restart with a clean boot, it requires repair.

1.Remove all accessories, including SDRAM modules, PC cards, printer, external monitor, pointing device, and keyboard.

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

3.Press the reset switch to return the notebook to a known state.

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

If the system fails after you make changes using the BIOS configuration utility, reset the notebook, enter the BIOS configuration utility, and install the defaults or correct the error.

Table 3-3. Insyde MobilePRO BIOS POST Beep Codes and Messages

Beep Code

Message

Description

5 short, 1 long

FAULTY DMA PAGE REGISTERS

DMA page registers do not function properly.

4 short, 1 long,

FAULTY REFRESH CIRCUIT

RAM refresh circuit does not function properly.

1 short

 

 

4 short, 2 long

ROM CHECKSUM INCORRECT

BIOS ROM checksum failed.

3 short; 1 long,

CMOS RAM TEST FAILED

CMOS RAM test failed.

2 short

 

 

3 short, 1 long,

DMA CONTROLLER FAULTY

DMA controller does not work properly.

1 short, 1 long

 

 

3 short; 2 long,

INTERRUPT CONTROLLER FAILED

Interrupt controller does not work properly.

1 short

 

 

3 short; 3 long

(None)

Keyboard controller failed to respond to the self-

 

 

test command.

2 short, 1 long;

(None)

No video device found.

3 short

 

 

2 short, 1 long;

(None)

No RAM installed.

2 short, 1 long

 

 

(None)

KEYBOARD CONTROLLER FAILURE

Keyboard controller failed during system inquiry

 

 

about connected devices.

(None)

KEYBOARD FAILURE

Keyboard fails to respond or no keyboard is

 

 

connected.

(None)

CMOS FAILURE - RUN SCU

CMOS data error, probably due to loss of battery

 

 

power.

(None)

CMOS CHECKSUM INVALID - RUN SCU

CMOS checksum error.

HP Pavilion zt1100/xz100 Omnibook xt1000

Troubleshooting and Diagnostics 3-25