Interpretation of Computer Error Beep Codes

You switch on your computer as usual and wait patiently as it goes through its startup routine. However, to your dismay, instead of the operating system booting in neatly, what you hear are mysterious beeps at startup. The computer beeps and fails to boot. Reminiscent of R2-D2's beeps and whistles language in 'Star Wars', your computer is trying to tell you what's wrong with it, in a coded, Morse code type language. By correctly interpreting the beeps, you can actually find out what's causing the booting process to fail. In this Buzzle article, I specifically interpret what error beeps at startup mean for different types of BIOS (Basic Input Output System) setups.

About Computer Error Beep Codes Displayed During POST
BIOS is the internal stabilization and control system of the computer, which oversees the working of all the constituent parts. It loads or boots the operating system and implements a complete status check before that. This test, known as Power-on Self Test or POST process detects computer problems and relays them to the user, through a cryptic 'beep' language. Every BIOS brand has its own beep code, which you will need access to, if you want to know what ails your computer. In the following lines, I help you in figuring out how to interpret computer error beep codes for various BIOS types, ranging from American Megatrends to Compaq and Award.

Interpreting the Beep Codes
To figure out what do 3 beeps mean on startup of a computer, you will have to first figure out the BIOS type of the computer. It appears on the screen during startup. If you can't see the startup screen, you can find the BIOS type, from the knowledge of the motherboard type. In the rest of this article, you will find a decoding table for most of the commonly used BIOS firmware, installed on computer motherboards.

Deciphering AMI BIOS Beep Error Code

AMI BIOS POST Error Codes
Beep Signal	Error Interpretation
1 Long Beep	No Error, Completion of POST Routine
1 Long, 2 Short Beeps	Video BIOS ROM failure
1 Long, 3 Short Beeps	Memory test has detected an error
1 Long, 8 Short Beeps	Video Adapter Error
2 Short Beeps	Hardware Test Failure During POST routine
1 Short Beep	Refresh failure in DRAM due to malfunctioning programmable interrupt timer
2 Short Beeps	RAM IC malfunction due to parity error in first 64 K memory
3 Short Beeps	Base memory failure in first 64 K of random access memory IC
4 Short Beeps	System timer IC failure
5 Short Beeps	CPU failure
6 Short Beeps	Keyboard controller IC failure, preventing gate A20 controlled processor switching to protected mode
7 Short Beeps	Exception error in CPU, due to faulty motherboard circuitry
8 Short Beeps	Defective system video adapter
9 Short Beeps	Defective BIOS ROM, check sum error
10 Short Beeps	CMOS shutdown failure
11 Short Beeps	Faulty L2 cache

Deciphering AST BIOS Beep Error Code

AST BIOS POST Error Codes
Beep Signal	Error Interpretation
1 Long Beep	Failure of Channel 0 DMAI controller IC
1 Long Beep, 1 Short Beep	Failure of Channel 1 DMAI controller IC
1 Long Beep, 2 Short Beeps	Failed video vertical retrace, due to video adapter failure
1 Long Beep, 3 Short Beeps	Video adapter memory failure
1 Long Beep, 4 Short Beeps	Complete video adapter failure
1 Long Beep, 5 Short Beeps	Base 64 KB memory failure in RAM IC
1 Long Beep, 6 Short Beeps	Inability of BIOS to load vertical vectors into memory
1 Long Beep, 7 Short Beeps	Video initialization failure due to faulty video adapters or motherboard
1 Long Beep, 8 Short Beeps	Complete video memory failure, due to faulty adapter or motherboard
1 Short Beep	Indicates failure of CPU register
2 Short Beeps	Failure of keyboard controller
3 Short Beeps	Motherboard circuitry error
4 Short Beeps	Communication failure with keyboard, due to faulty keyboard controller IC or a faulty keyboard
5 Short Beeps	Keyboard input malfunction, due to keyboard controller IC failure
6 Short Beeps	Motherboard chipset failure
9 Short Beeps	BIOS ROM Failure
10 Short Beeps	System timer IC failure
11 Short Beeps	Motherboard Failure
12 Short Beeps	CMOS IC/Real time clock failure

Deciphering Award BIOS Beep Error Code

Award BIOS POST Error Codes
Beep Signal	Error Interpretation
1 Long, 2 Short Beeps	Error in video adapter or loose monitor cable
1 Long, 3 Short Beeps	Absent or Loosely Inserted Video Card
Repeated Beeps	Missing or loosely inserted memory IC
Rapid Beeping During Operation	CPU Overheating
Repeated High or Low Beeps	Damaged, overheated or loosely inserted CPU

Deciphering Compaq BIOS Beep Error Code

Compaq BIOS POST Error Codes
Beep Signal	Error Interpretation
1 Short Beep	Not an error, system booting smoothly
1 Long, 1 Short Beep	Checksum Error in BIOS ROM
1 Long, 2 Short Beeps	Improperly connected or faulty video adapter
7 Beeps (Only for Compaq Deskpro)	Faulty AGP video card
Continuous Beep	RAM error/Faulty RAM
1 Short, 2 Long Beeps	Improperly connected RAM or Faulty RAM

Deciphering Phoenix BIOS Beep Error Code
(Phoenix BIOS error codes are a combination of beeps with pauses in between. Here 2-1-2 means, 2 beeps, pause, 1 beep, pause, 2 beeps)

Phoenix BIOS POST Error Codes
Beep Signal Sequence	Error Interpretation
1-1-2	CPU malfunction, may need replacement
1-1-2 (Low volume beeps)	Motherboard Fault
1-1-3	Real time clock error or faulty CMOS, in need of replacement
1-1-3 (Low volume beeps)	Failure of extended CMOS RAM
1-1-4	Checksum error in BIOS ROM
1-2-1	Failure of programmable input timer (PIT)
1-2-2	Failure of DMA controller IC
1-2-3	Failure of DMA controller
1-3-1	Failure of RAM refresh controller
1-3-2	RAM (64 KB) failure
1-3-3	Dysfunctional first RAM IC
1-3-4	Failure of RAM control logic
1-4-1	Failure of address line to first 64 KB RAM
1-4-2	RAM parity failure, indicating RAM IC malfunctioning
1-4-3	Motherboard Failure detected by EISA fail-safe timer test
1-4-4	Motherboard Failure detected by EISA NMI port 462 test
2-1-1	Failure of Bit 0 on first (64 KB) RAM IC
2-1-2	Failure of Bit 1 on first (64 KB) RAM IC
2-1-3	Failure of Bit 2 on first (64 KB) RAM IC
2-1-4	Failure of Bit 3 on first (64 KB) RAM IC
2-2-1	Failure of Bit 4 on first (64 KB) RAM IC
2-2-2	Failure of Bit 5 on first (64 KB) RAM IC
2-2-3	Failure of Bit 6 on first (64 KB) RAM IC
2-2-4	Failure of Bit 7 on first (64 KB) RAM IC
2-3-1	Failure of Bit 8 on first (64 KB) RAM IC
2-3-2	Failure of Bit 9 on first (64 KB) RAM IC
2-3-3	Failure of Bit 10 on first (64 KB) RAM IC
2-3-4	Failure of Bit 11 on first (64 KB) RAM IC
2-4-1	Failure of Bit 12 on first (64 KB) RAM IC
2-4-2	Failure of Bit 13 on first (64 KB) RAM IC
2-4-3	Failure of Bit 14 on first (64 KB) RAM IC
2-4-4	Failure of Bit 15 on first (64 KB) RAM IC
3-1-1	Failure of slave DMA register, leading to DMA controller malfunction
3-1-2	DMA controller failure due to faulty master DMA register
3-1-3	Faulty interrupt controller IC
3-1-4	Failure of Interrupt controller IC
3-2-2	BIOS failure in loading interrupt vectors, motherboard may need replacement
3-2-4	Faulty keyboard controller IC
3-3-1	CMOS RAM or CMOS battery failure
3-3-2	CMOS configuration failure
3-3-4	Video memory or video adapter failure
3-4-1	Video adapter failure leading to video initialization problems
4-2-1	System timer IC failure
4-2-2	CMOS IC failure
4-2-3	Keyboard controller failure
4-2-4	Unexpected Interrupt caused due to a CPU problem
4-3-1	Faulty RAM addressing circuitry
4-3-3	System timer IC failure
4-3-4	CMOS internal real time clock failure
4-4-1	Faulty serial port circuitry
4-4-2	Faulty parallel port circuitry
4-4-3	Math coprocessor failure

So you need a good ear to interpret what the code says. Once you know the beep sequence, you can figure out what's wrong with your computer, to take appropriate action. The beauty of the beep code lies in the fact that you can interpret what's wrong, even when the monitor is not working and nothing is being displayed. Listen to the beeps, decipher them correctly from the diagnostic tables provided above and fix up your computer problem!