Definitions and Solutions For BIOS Error Beeps and Messages/Codes

Published on: June 21, 2000
Last Updated: June 21, 2000

This information and much more can be found in the BIOS Companion Book.

AMI BIOS Award BIOS Apricot Compaq General HP Vectra IBM AT Olivetti Phoenix Sirius

Audio Beep Errors:

Number of Beeps Description of Problem Solution
1 beepDRAM refresh failureTry re-seating the memory first. If the error still occurs, replace the memory with known good chips.
2 beepsParity Circuit Failure
3 beepsBase 64K RAM failure
4 beepsSystem Timer FailureSend System Board in for Repair
5 beepsProcessor Failure
6 beepsKeyboard Controller / Gate A20 FailureTry 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 beepsVirtual Mode Exception ErrorSend System Board in for Repair
8 beepsDisplay Memory Read/Write FailureIndicates 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.
9 beepsROM BIOS Checksum FailureIndicates 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 AMI product distributor for replacement part(s).
10 beepsCMOS Shutdown Register Read/Write ErrorSend System Board in for Repair
1 long 2 shortVideo failureReseat the video board – replace if board is determined to be faulty.
1 long 3 shortVideo failure
1 longPOST passed.No Errors

Error Messages/Codes

Error MessageProblemSolution
CH-2 Timer ErrorNon fatal. Could be caused by a peripheral.
INTR #1 ErrorInterrupt Channel 1 has failed the POST testCheck system boards for IRQs 0-7.
INTR #2 ErrorInterrupt Channel 2 has failed the POST testCheck system boards for IRQs 8-15.
CMOS Battery State LowReplace battery.
CMOS Checksum FailureA 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 MismatchUsually 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 SetCMOS values are either corrupt or do not exist.Run Setup.
Display Switch Not ProperMany 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 itUnlock the keyboard.
Keyboard ErrorThere is a problem with the keyboardMake 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 ErrorThere is a problem with the keyboard connector on the motherboard.
FDD Controller FailureThe BIOS cannot communicate with the floppy drive controller.The floppy may be disabled, also check that the cable is not loose.
HDD Controller FailureAs above, but for hard disks.
C: Drive ErrorThe 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 ErrorSame as above except for drive D.Same as above.
C: Drive FailureThe drive was detected but failed. More serious than error.
D: Drive FailureSame as above.
CMOS Time and Date Not SetRun 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 ShortThere 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 ErrorThere is an error in the first DMA channel on the motherboardCould be caused by a peripheral device.
DMA ErrorThere 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 FailureThe diskette in the specified boot-up drive is corrupt.
Invalid Boot DisketteSame as above, but the disk is readable.
On Board Parity ErrorThere 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 ErrorThere is a parity error with memory installed in an expansion slot at address XXXX (hex)Same as above.
Parity ErrorThere is a parity error with memory somewhere in the system.Same as above.
Memory Parity Error at XXXXMemory has failed. If it cannot be determined, it is displayed as XXXX, if not, as ????Same as above.
I/O Card Parity Error at XXXXSame as above.Same as above.
DMA Bus Time-outA 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 SetupDisable Memory Relocation if possible.
EISA CMOS Checksum FailureThe checksom for EISA CMOS is bad, or the battery is bad.
EISA CMOS InoperationalA read/write failure occured in extended CMOS RAM.The battery may be bad.
Expansion Board not ready at Slot XAMI 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 InoperationalDevices that depend on the fail-safe NMI timer are not operating correctly.
ID information mismatch for Slot XThe ID of the EISA expansion board in slot X does not match the ID in CMOS RAM.
Invalid Configuration Information for Slot XThe configuration information for EISA board X is not correct.Run the ECU.
Software Port NMI InoperationalThe software port NMI is not working.
BUS Timeout NMI at Slot XThere 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 XThe expansion board NMI was generated from slot X.
Fail-Safe Timer NMIA fail-safe timer NMI has been generated.
Software Port NMIA software port NMI has been generated.

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Written by Bobby

Bobby Lawson is a seasoned technology writer with over a decade of experience in the industry. He has written extensively on topics such as cybersecurity, cloud computing, and data analytics. His articles have been featured in several prominent publications, and he is known for his ability to distill complex technical concepts into easily digestible content.
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