BIOS Beep Codes

When a computer is first turned on, or rebooted, its BIOS performs a power-on self test (POST) to test the system's hardware, checking to make sure that all of the system's hardware components are working properly. Under normal circumstances, the POST will display an error message; however, if the BIOS detects an error before it can access the video card, or if there is a problem with the video card, it will produce a series of beeps, and the pattern of the beeps indicates what kind of problem the BIOS has detected.
Because there are many brands of BIOS, there are no standard beep codes for every BIOS.

The two most-used brands are AMI (American Megatrends International) and Phoenix.

AMI Beep Codes

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.