Troubleshooting Boot Process Errors

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The BIOS performs a power-on self-test (POST) when it starts up the system, to check out the PC and make sure that everything is working properly. Assuming that the BIOS is able to boot the system far enough to gain access to the video subsystem, it will display information about the PC as it boots. It will also use the video system to communicate error messages to the user. In fact, most boot problems are displayed via video error messages, as opposed to audio beep codes. For more information on beep codes, see AMI Beep Codes or Award Beep Codes.

An error message can be produced by various different parts of the system during the POST process, depending on how far into the boot process the system gets before it is occurs. Most error messages are produced by the system BIOS, as it is responsible for most of the functions occur during boot. Other error messages are operating-system-specific.

There are many thousands of individual error messages; some are more common than others because there are only a few different BIOS companies that are used by the majority of PCs out there today. You should note though that the exact wording of an error message can be changed by the manufacturer of each system or motherboard, thereby providing for a multitude of variations.

In most cases, the messages are pretty similar to each other, and you may see slightly different wording in the error message you see as opposed to the ones listed here. Essentially though, if the messages appear similar, it is probably safe to follow the diagnosis here. "Disk drive failure" and "Diskette drive failure" are what we would consider similar in nature, however you may want to consult your motherboards owner's manual regarding any unusual messages, or to ensure that your manufacturer means the same thing with their messages that other companies do.

Additional Notes:

A20 Line or 8042 Gate Error  Keyboard Clock Line Failure
Detected Short in Address Line  Keyboard Controller Failure
BIOS ROM Checksum Errors  Keyboard Data Line Failure
Level 2 Cache Failure  Keyboard Error
 CH-1 Timer (Timing) Error  Keyboard Error or
        No Keyboard Present
 CH-2 Timer (Timing) Error  Keyboard Error: nn
 CMOS Battery Fail  Keyboard Interface Error
 CMOS Battery Low  Keyboard is Locked - Unlock
 CMOS Checksum Error
        - defaults loaded
 Keyboard is Locked -
        Unlock the Key
 CMOS Checksum Error  Keyboard Locked
 CMOS Checksum Failed  Keyboard Stuck Key Failure
 CMOS Display Type Mismatch  Memory Access Failure
CMOS Memory Size Mismatch  Memory Address Error at xxx
CMOS Information Invalid  Memory Failure at xxx,
        read xxx, expecting xxx
CMOS System Options not Set  Memory Parity Error at xxxx
Clearing a Corrupt CMOS  Memory Size has changed
        since last boot
CMOS Date and Time Not Set  Memory Size in CMOS Invalid
CPU Reported as XXX
        (Where XXX = speed)
 Memory Test Fail
Disk Boot Failure - Insert
        system disk and press Enter
 Memory Test
Disk Boot Failure  Memory Verify Error at xxx
 Diskette Boot Failure  Missing Operating System
 Diskette Drive Failure  No Boot Device
 Diskette Drive x Failure
        (with x= 1, 2, A or B)
 No Boot Device Available -
        Press F1 to retry boot
Diskette Drive or Type Mismatch
        Error - Run Setup
No Boot Sector on Hard Disk
 Diskette Read Failure - Press F1
        to restart system
 No Boot Device Available -
        Press F1 to retry boot,
        F2 for setup utility
 Display Adapter Failed -
        Using Alternate
No Boot Sector on Fixed Disk -
        Press F1 to retry boot
 Display Switch is Set Incorrectly  No Boot Sector on Fixed Disk -
        Press F1 to retry boot,
        F2 for setup utility
 Display Type has changed since
        last boot
 No ROM BASIC - System Halted
 Display switch not proper  No Timer Tick Interrupt
 DMA #1 Error  Non-system Disk -
        Replace and press any key
 DMA #2 Error  Not a Boot Diskette
 DMA Bus Timeout  Not a Boot Diskette -
        Press F1 to retry boot
 DMA Error  Operating System Not Found
 Error Encountered Initializing
        Hard Drive
 Option ROM Checksum Failure
 Error Encountered Initializing Hard
        Drive Controller
 Override Enabled - Defaults Loaded
 Error with Hard Disk  Parity Check
 Failing Bits: xxx Memory Access
        Problem
 Parity Error ????
 Fixed Disk Controller Failure  Press F1 to Disable NMI,
        F2 to Reboot
 Fixed Disk Read Failure -
        Press F1 to Retry Boot
 Primary Master Hard Disk Failure
 Fixed Disk Configuration Error  Primary Slave Hard Disk Failure
 Fixed Disk Failure  Real Time Clock Error
 Fixed Disk x Failure (where x may
        be 0, 1, 2 or 3 or A, B, C or D etc)
 Real Time Clock Failure
 Floppy Drive Mismatch  RAM Parity Error
 Floppy Disk Controller Failure  ROM Error
 Floppy Disk Controller Error or
        No Controller Present
 Secondary Master Hard Disk
        Failure
 Floppy Disk(s) Fail  Secondary Slave Hard Disk Failure
 Gate A20 Error  Shadow RAM Failed
 Hard Disk CMOS Mismatch  Shutdown Failure
 Hard Disk Initializing: Please
        wait a moment
 Static Resource Conflict
 Hard Disk Install Failure  System Battery is Dead
 Hard Disk Diagnosis Fail  System Cache Error -
        Cache Disabled
Hard Drive Controller Failure  System CMOS Checksum Bad
HDD Controller Failure  System RAM Failed at Offset xxxx
I/O Card Parity Error at xxxxx  System Timer Error
Incorrect Drive A Type  Time of Day Clock Stopped
Incorrect Drive B Type  Time of Day Not Set -
        Run Setup Program
Internal Cache Test Failed -
        Cache is Disabled
 Timer ½ Failure
 Interrupt Error  Timer Error
 Interrupt Controller Failure  Unable to Control A20 Line
 Int #1/#2 Error  Unexpected Interrupt in Protected
        Mode
 Invalid Configuration Information -
        Please Run Setup
 Updating ESCD
 Invalid Media Type  XXXX ROM Error
 Invalid Partition Table  XXXXH Option ROM Checksum
       Failure

 

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