written by: Steve McFarlane•edited by: Bill Fulks•updated: 5/21/2010
Motherboard beep error codes are used to alert computer owners of hardware problems. Here is what one long beep and other audio codes mean.
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As soon as a computer is turned on it goes through the POST (Power On Self Test). The computer does this to ensure that key hardware components are present and working. IBM compatible computers will usually beep once to signal that all hardware components have past the power on system test. Should a component fail, the computer will sound an alarm. If it doesn’t, that is an indication that something is wrong as well.
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What One Long Beep Means
Motherboard audio alerts are also known as BIOS beep codes or motherboard audio codes. Each audio code sequence can tell the listener exactly what has gone wrong, which can really help a technician to quickly troubleshoot what needs to be fixed. If you hear one long beep or repeated long beeps, there is most likely a problem with one or all of the computer’s memory modules.
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How to Fix Faulty Memory
In some cases, especially if someone had been working on the motherboard or was in the systems unit (computer case or motherboard enclosure), the memory modules can become unseated. If you are fortunate, the problem can be resolved by simply reseating the memory cards. Resolve a memory error code by using these steps.
Shutdown the Computer and Unplug the power cable.
Set the system unit on its side and remove the screws (if applicable) to access the inside.
Touch any exposed metal, on the case, to discharge any static that has built up in your body or use a antistatic wrist band.
Remove each memory module and firmly reseat it. While you are at it, check to see if the motherboard is damaged in any way before trying to reseat the memory modules.
Plug in the power cord and test to see if the problem is fixed.
If the problem is not resolved, you may need to swap around the memory modules until you find the one that is not working.
If all the memory modules seem to be faulty consider purchasing replacements.
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Manufacturer Specific BIOS Codes
The sequence of beeps that you hear for the audio error beep codes, will, in part, depend on who manufactured the motherboard's BIOS or CMOS. Phoenix or AMI bios audio codes are very popular but most motherboard manufacturers seem to base their BIOS audio codes on a standard developed by IBM. If you hear a series of long single beeps, you are probably using a BIOS that uses IBM based audio codes.
IBM Audio Codes
No Beeps Short - No power, Bad CPU/MB, Loose Peripherals
One Beep - Everything is normal and Computer POSTed fine
Two Beeps - POST/CMOS Error
One Long Beep, One Short Beep - Motherboard Problem
One Long Beep, Two Short Beeps - Video Problem
One Long Beep, Three Short Beeps - Video Problem
Three Long Beeps - Keyboard Error
Repeated Long Beeps - Memory Error
Continuous Hi-Lo Beeps - CPU Overheating
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Listening to the BIOS audio codes can provide a quick and easy way for computer technicians and users alike to quickly determine what is wrong with a computer. While audio error codes vary according to their manufacturer, most follow the IBM standard. If your motherboard makes one long beep then you almost definitely have a memory problem to resolve.
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Image: "Motherboard Beep Error Codes - One Long Beep" Aressauburn. http://www.flickr.com/photos/aresauburnphotos/2488601546/