Computer POST and beep codes

Computer POST and beep codes

The computer POST (power-on self-test) checks a computer's internal hardware for compatibility and connection before starting the remainder of the boot process. If the computer passes the POST, the computer may give a single beep (some computers may beep twice) as it starts and continue to boot. However, if the computer fails the POST, the computer will either not beep or generate a beep code that tells the user the source of the problem.

If your computer has an irregular POST or a beep code not mentioned below, follow thePOST troubleshooting steps to determine the failing hardware component.

AMI BIOS beep codes
Award BIOS beep codes
Dell beep codes
IBM BIOS beep codes

AMI BIOS beep codes

Below are the AMI BIOS Beep codes that can occur. However, because of the wide variety of different computer manufacturers with this BIOS, the beep codes may vary.

Beep Code.    Descriptions

1 shortDRAM refresh failure
2 shortParity circuit failure
3 shortBase 64K RAM failure
4 shortSystem timer failure
pa nan5 shortProcess failure
6 shortKeyboard controller Gate A20 error
7 shortVirtual mode exception error
8 shortDisplay memory Read/Write test failure
9 shortROM BIOS checksum failure
10 shortCMOS shutdown Read/Write error
11 shortCache Memory error
1 long, 3 shortConventional/Extended memory failure
1 long, 8 shortDisplay/Retrace test failed
two-tone sirenLow CPU Fan speed, Voltage Level issue

AWARD BIOS beep codes

Below are Award BIOS Beep codes that can occur. However, because of the wide variety of different computer manufacturers with this BIOS, the beep codes may vary.

Beep Code.     Description

1 long, 2 shortIndicates a video error has occurred and the BIOS cannot initialize the video screen to display any additional information
1 long, 3 shortVideo card not detected (reseat video card) or bad video cardBeeps repeating endlesslyRAM problem.
Repeated high frequency beeps while PC is runningOverheatingprocessor (CPU)
Repeated beeps alternating high & low frequencyIssue with the processor (CPU), possibly damaged

If any other correctable hardware issues are found, the BIOS displays a message.

Dell beep codes

Beep Code.     Description
1 beepBIOS ROMcorruption or failure
2 beepsMemory (RAM) not detected
3 beepsMotherboardfailure
4 beepsMemory (RAM) failure
5 beepsCMOS Batteryfailure
6 beepsVideo cardfailure
7 beepsBad processor (CPU)

For other Dell beep codes, please refer toDell's Beep Codes and PSA Diagnostics Chartpage.

IBM BIOS beep codes

Below are general IBM BIOS Beep codes that can occur. However, because of the wide variety of models shipping with this BIOS, the beep codes may vary.

Beep Code.     Description

No BeepsNo Power, Loose Card, or Short.
1 Short BeepNormal POST, computer is ok.
2 Short BeepPOST error, review screen for error code.Continuous BeepNo Power, Loose Card, or Short.
Repeating Short BeepNo Power, Loose Card, or Short.
1 Long and 1 Short BeepMotherboard issue.
1 Long and 2 Short BeepsVideo (Mono/CGA Display Circuitry) issue.
1 Long and 3 Short Beeps.Video (EGA) Display Circuitry.
3 Long BeepsKeyboard or Keyboard card error.
1 Beep, Blank or Incorrect DisplayVideo Display Circuitry.