BIOS Troubleshooting

Now we come to the BIOS troubleshooting. You have passed all the 'obstacles' and tests in building a computer.

Now, you have had all the components properly installed, let's turn own the power.

If your system is ok, you'll hear a beep sound, if you hear beep sound more than once, that mean's you didn't install the components properly or some of the components might be faulty.

You should have properly installed your motherboard as well as other computer parts.

Press [DEL] during the POST (Power On Self Test), and you'll enter the world of BIOS (Basic Input Output System).


As illustrated above (sorry, it's a bit blur), you should select the [LOAD OPTIMIZED DEFAULTS] for top performance.

If you aren't sure of the rest of the functions, just leave them alone, they should be ok with the Optimized Defaults.

Just select [SAVE & EXIT SETUP], press [Y] to save.

Viola, you have got the system up!!!

Wow, great job.

Fujitsu Computer Systems Corporation


Well, sometimes we might not get all the things done in our life, same applied to computer hardware-building.

When you power on your system, you might hear a single long beep, and this means OK, don't worry. But, if you hear any sound more than a single beep, then you are in deep water.

No worries, just refer to the below BIOS error tips.

BIOS Audio Beep Errors

Number of Beeps

Description of Problem


1 beep

DRAM refresh failure

Try re-seating the memory first. If the error still occurs, replace the memory with known good chips.

2 beeps

Parity Circuit Failure


3 beeps

Base 64K RAM failure


4 beeps

System Timer Failure

Send System Board in for Repair

5 beeps

Processor Failure


6 beeps

Keyboard Controller / Gate A20 Failure

Try re-seating the keyboard controller chip. If the error still occurs, replace the keyboard chip. If the error persists, check parts of the system relating to the keyboard, e.g. try another keyboard, check to see if the system has a keyboard fuse.

7 beeps

Virtual Mode Exception Error

Send System Board in for Repair

8 beeps

Display Memory Read/Write Failure

Indicates a memory error on the video adapter. Try re-seating the video card. If it still beeps, try replacing the video card or the memory on the video card.

If it is built-in VGA, then please send System Board in for repair.

9 beeps

ROM BIOS Checksum Failure

Indicates faulty BIOS chip(s). It is not likely that this error can be corrected by re-seating the chips. Consult the motherboard supplier or an BIOS product distributor for replacement part(s).

10 beeps

CMOS Shutdown Register Read/Write Error

Send System Board in for Repair

1 long 2 short

Video failure

Reseat the video board - replace if board is determined to be faulty.

1 long 3 short

Video failure


1 long

POST passed.

No Errors

.Mac (Apple Computer, Inc.)

BIOS Error Messages/Codes


Error Message



CH-2 Timer Error

Non fatal. Could be caused by a peripheral.


INTR #1 Error

Interrupt Channel 1 has failed the POST test

Check system boards for IRQs 0-7.

INTR #2 Error

Interrupt Channel 2 has failed the POST test

Check system boards for IRQs 8-15.

CMOS Battery State Low


Replace battery.

CMOS Checksum Failure

A checksum is generated when CMOS values are saved for error checking on subsequent startups. This error message will appear if the checksum is different from one boot-up to the next.

Run the setup program again to correct the problem.

CMOS Memory Size Mismatch

Usually caused when you add or remove memory from your system but could be caused by memory that has failed.

Run setup.

CMOS System Optons Not Set

CMOS values are either corrupt or do not exist.

Run Setup.

Display Switch Not Proper

Many motherboards have a jumper setting that allows you to specify whether you have a color or monochrome monitor.

Correct the switch position.

Keyboard is locked ... Unlock it


Unlock the keyboard.

Keyboard Error

There is a problem with the keyboard

Make sure your keyboard BIOS is compatible, that the keyboard is plugged in completely, and that no keys are stuck. Or, change the BIOS keyboard setting to "Not Installed" to skip the test.

K/B Interface Error

There is a problem with the keyboard connector on the motherboard.


FDD Controller Failure

The BIOS cannot communicate with the floppy drive controller.

The floppy may be disabled, also check that the cable is not loose.

HDD Controller Failure

As above, but for hard disks.


C: Drive Error

The system cannot get a response from drive C.

The hard disk type is most likely set incorrectly, or the disk may not be formatted or connected properly.

D: Drive Error

Same as above except for drive D.

Same as above.

C: Drive Failure

The drive was detected but failed. More serious than error.


D: Drive Failure

Same as above.


CMOS Time and Date Not Set


Run Setup

Cache Memory Bad, do Not Enable Cache!


Cache may indeed be bad, if so replace. May simply need re-seating.

8042 Gate-A20 Error!

The Gate-A20 portion of the keyboard controller has failed.

Replace the keyboard chip (8042)

Address Line Short

There is a problem with the memory address decoding circuitry.

Try rebooting, (turn the system off and then on 10 seconds later). The problem may correct itself.

DMA #1 Error

There is an error in the first DMA channel on the motherboard

Could be caused by a peripheral device.

DMA Error

There is an error within the DMA controller on the motherboard.


No ROM Basic.

There is nothing to boot from. (i.e.- the system cannot find an operating system).

Be certain that a bootable disk is defined in the system setup.

Diskette Boot Failure

The diskette in the specified boot-up drive is corrupt.


Invalid Boot Diskette

Same as above, but the disk is readable.


On Board Parity Error

There is a parity error with memory on the motherboard at address XXXX (hex). (On Board specifies that the memory is not on an expansion board, but rather is located on the motherboard physically).

Possibly correctable with software from the motherboard manufacturer. (also do a Virus Check - some viruses cause parity errors).

Off Board Parity Error

There is a parity error with memory installed in an expansion slot at address XXXX (hex)

Same as above.

Parity Error

There is a parity error with memory somewhere in the system.

Same as above.

Memory Parity Error at XXXX

Memory has failed. If it cannot be determined, it is displayed as XXXX, if not, as ????

Same as above.

I/O Card Parity Error at XXXX

Same as above.

Same as above.

DMA Bus Time-out

A device has driven the bus signal for more than 7.8 microseconds.

Troubleshoot all system boards. (remove them and try to isolate the failure)

Memory mismatch, run Setup


Disable Memory Relocation if possible.

EISA CMOS Checksum Failure

The checksom for EISA CMOS is bad, or the battery is bad.


EISA CMOS Inoperational

A read/write failure occured in extended CMOS RAM.

The battery may be bad.

Expansion Board not ready at Slot X

BIOS cannot find the expansion board in X slot.

Verify that the board is in the correct slot and is seated properly.

Fail-Safe Timer NMI Inoperational

Devices that depend on the fail-safe NMI timer are not operating correctly.


ID information mismatch for Slot X

The ID of the EISA expansion board in slot X does not match the ID in CMOS RAM.


Invalid Configuration Information for Slot X

The configuration information for EISA board X is not correct.

Run the ECU.

Software Port NMI Inoperational

The software port NMI is not working.


BUS Timeout NMI at Slot X

There was a bus timeout NMI at Slot X.


(E)nable (D)isable Expansion Board?


Type E to enable the board that had an NMI or D to disable it.

Expansion Board disabled at Slot X

The expansion board NMI was generated from slot X.


Fail-Safe Timer NMI

A fail-safe timer NMI has been generated.


Software Port NMI

A software port NMI has been generated.