BIOS Beep Codes

One of the nice things about working on computers is that when it comes to the raw hardware of a system, the engineers have designed a way to communicate what’s wrong (even if it’s just a general idea) even when the hardware has a pretty serious problem. When a computer boots it goes through a POST *(Power On Self Test). This POST process basically is the BIOS (Software embedded in the hardware of the system that exists whether or not an Operating System like Windows is installed) “waking up and testing the hardware.”

From the Wikipedia:

The principal duties of the main BIOS during POST are as follows:

verify the integrity of the BIOS code itself
determine the reason POST is being executed
find, size, and verify system main memory
discover, initialize, and catalog all system buses and devices
pass control to other specialized BIOSes (if and when required)
provide a user interface for system configuration
identify, organize, and select which devices are available for booting
construct whatever system environment that is required by the target OS

When the BIOS runs this test it usually gives a Beep Code to report the results. Usually it is a successful one or two short beeps.

The bad news is that different system boards have BIOS from different manufacturers and there is NO standard for the beep codes. Even with a given BIOS there may be some variations. Usually, a quick google search for the system board model, or a look at the motherboard manual will give the interpretation for the beeps.

Here are some of the more common ones though (Amibios is listed first)…

1 beep DRAM refresh failure. There is a problem in the system memory or the motherboard.
2 beeps Memory parity error. The parity circuit is not working properly.
3 beeps Base 64K RAM failure. There is a problem with the first 64K of system memory.
4 beeps System timer not operational. There is problem with the timer(s) that control functions on the motherboard.
5 beeps Processor failure. The system CPU has failed.
6 beeps Gate A20/keyboard controller failure. The keyboard IC controller has failed, preventing gate A20 from switching the processor to protect mode.
7 beeps Virtual mode exception error.
8 beeps Video memory error. The BIOS cannot write to the frame buffer memory on the video card.
9 beeps ROM checksum error. The BIOS ROM chip on the motherboard is likely faulty.
10 beeps CMOS checksum error. Something on the motherboard is causing an error when trying to interact with the CMOS.
11 beeps Bad cache memory. An error in the level 2 cache memory.
1 long beep, 2 short Failure in the video system.
1 long beep, 3 short A failure has been detected in memory above 64K.
1 long beep, 8 short Display test failure.
Continuous beeping A problem with the memory or video.

There are a lot of Award Bios possibilities, but here are some…

Award BIOS Beep Codes:

1long, 2 short Video adapter error Either video adapter is bad or is not seated properly. Also, check to ensure the monitor cable is connected properly.
Repeating (endless loop) Memory error Check for improperly seated or missing memory.
1long, 3short No video card or bad video RAM Reseat or replace the video card.
High frequency beeeps while running Overheated CPU Check the CPU fan for proper operation. Check the case for proper air flow.
Repeating High/Low CPU Either the CPU is not seated properly or the CPU is damaged. May also be due to excess heat. Check the CPU fan or BIOS settings for proper fan speed.

Phoenix Bios uses a different approach. They use beeps in sets of either 3 or 4 beeps with a pause between each set. A list of those codes can be found here. Usually the manufacturer of your system board will have a list of beep codes to help diagnose what’s going on with the system. Usually these indicate problems with a)system board, b) memory c)cpu d)video card… as those are the essential pieces of hardware. As you might notice above there is some detail to find WHAT the issue is with the system board, or that the problem is the cpu’s cache memory as opposed to main system memory…

(Couldn’t they have used some sort of Morse Code??? Even abbreviating where necessary. No need to spell out Central Processor Unit, CPU works fine, OK would be a bit longer than the usual one short beep. (One short beep in Morse is E. ((E)verything’s OK??)))

Another good reference for POST Beep codes is

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