Chapter 5: Troubleshooting

POST Code Listing (AMI Motherboard only)

POST Code Listing (AMI Motherboard only)

Use the following listing to troubleshoot the motherboard. You will need a POST (Power-On Self Test) card installed in an ISA slot to use this listing.

POST Code Listing

Checkpoint

 

Code

Description

D0h

The NMI is disabled. Power on delay is starting. Next, the initialization code checksum will be

 

verified.

D1h

Initializing the DMA controller.

D3h

Starting memory sizing next.

D4h

Returning to real mode. Executing any OEM patches and setting the stack next.

D5h

Passing control to the uncompressed code in shadow RAM at E000:0000h. The initialization code

 

is copied to segment 0 and control will be transferred to segment 0.

D6h

Control is in segment 0. Next, checking if Home was pressed and verifying the BIOS checksum. If

 

either Home was pressed or the system BIOS checksum is bad, next will go to checkpoint code

 

E0h. Otherwise, going to checkpoint code D7h.

Bootblock Recovery Codes

The bootblock recovery checkpoint codes are listed in order of execution:

Code

Description

E0h

The onboard floppy controller, if available, is initialized. Next, beginning the base 512 KB memory

 

test.

E1h

Initializing the interrupt vector table next.

E2h

Initializing the DMA and Interrupt controllers next.

E6h

Enabling the floppy drive controller and Timer IRQs. Enabling internal cache memory.

EDh

Initializing the floppy drive.

EEh

Looking for a floppy diskette in drive A:. Reading the first sector of the diskette.

EFh

A read error occurred while reading the floppy disk in drive A:.

E0h

Next, searching for the AMIBOOT.ROM file in the root directory.

F1h

The AMIBOOT.ROM file is not in the root directory.

F2h

Next, reading and analyzing the floppy diskette FAT to find the clusters occupied by the

 

AMIBOOT.ROM file.

F3h

Next, reading the AMIBOOT.ROM file, cluster by cluster.

F4h

The AMIBOOT.ROM file is not the correct size.

F5h

Next, disabling internal cache memory.

FBh

Next, detecting the type of flash ROM.

FCh

Next, erasing the flash ROM.

FDh

Next, programming the flash ROM.

FFh

Flash ROM programming was successful. Next, restarting the system BIOS.

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Agilent Technologies 54835A, 45A, 46A manual Post Code Listing AMI Motherboard only, Checkpoint Code Description