The beeps that are emitted from the computer to its launch have a special meaning, because according to their sequence can recognize different types of error.
Following is the list of the main acoustic signals by producer BIOS if your BIOS manufacturer is not listed make any reference to the standard IBM

Beep Code

What it means

Possible cause

 1 - 1 - 2

 CPU / motherboard failure

 Defective CPU / motherboard

 1 - 1 - 3

 CMOS read/write failure

 Defective motherboard

 1 - 1 - 4

 BIOS ROM failure

 Defective BIOS chip

 1 - 2 - 1

 Timer failure

 Defective motherboard

 1 - 2 - 2 or  1 - 2 - 3

 DMA failure

 Defective motherboard

 1 - 3 - 1

 Memory refresh failure

 Defective memory

 1 - 3 - 2 or  1 - 3 - 3 or  1 - 3 - 4

 64K memory failure

 Defective memory

 1 - 4 - 1

 Address line failure

 Defective memory

 1 - 4 - 2

 Parity error

 Defective memory

 1 - 4 - 3

 Timer failure

 Defective motherboard

 1 - 4 - 4

 NMI port failure

 Defective motherboard

 2 - x - x

 64K memory failure

 Defective memory

 3 - 1 - 1

 Slave DMA failure

 Defective motherboard

 3 - 1 - 2

 Master DMA failure

 Defective motherboard

 3 - 1 - 3

 Interrupt controller failure

 Defective motherboard

 3 - 1 -4

 Slave IC failure

 Defective motherboard

 3 - 2 -2

 Interrupt Controller failure

 Defective motherboard

 3 - 2 - 3

 

 

 3 - 2 - 4

 Keyboard control failure

 Defective motherboard

 3 - 3 - 1

 CMOS batter failure

 Defective CMOS battery

 3 - 3 - 2

 CMOS configuration error

 Incorrect setting

 3 - 3 - 3

 

 

 3 - 3 - 4

 Video memory failure

 Defective video card or memory

 3 - 4 - 1

 Video init failure

 Defective video card or memory

 4 - 2 - 1

 Timer failure

 Defective motherboard

 4 - 2 - 2

 CMOS shutdown failure

 Defective motherboard

 4 - 2 - 3

 Gate A20 failure

 Defective motherboard

 4 - 2 - 4

 Unexpected interrupt

 Defective processor

 4 - 3 - 1

 RAM test failure

 Defective memory

 4 - 3 - 3

 Timer failure

 Defective motherboard

 4 - 3 - 4

 RTC failure

 Defective motherboard

 4 - 4 - 1

 Serial port failure

 Defective motherboard

 4 - 4 - 2

 Parallel port failure

 Defective motherboard

 4 - 4 - 3

 Coprocessor failure

 Defective motherboard or CPU.

 9 - 2 - 1

 Video adapter incompatibility

 Use a different brand of video card

AMI BIOS Beep Codes

Beep Code

What it means

Possible cause

 1 Beep (No video)

 Memory refresh failure

 Defective memory

 2 Beeps

 Memory parity error

 Defective memory

 3 Beeps

 Base 64K memory failure

 Defective memory

 4 Beeps

 Timer not operational

 Defective motherboard

 5 Beeps

 Processor error

 Defective processor

 6 Beeps

 8042 Gate A20 failure

 Defective CPU or Motherboard

 7 Beeps

 Processor exception

 Defective processor

 8 Beeps

 Video memory error

 Defective video card or memory

 9 Beeps

 ROM checksum error

 Defective BIOS

10 Beeps

 CMOS checksum error

 Defective motherboard

11 Beeps

 Cache memory Defective

 Defective CPU or motherboard

Award BIOS Beep Codes:

Sequenza segnale acutisco

Beep Code

Cosa significa

What it means

Possibili cause

Possible cause

 1 Long, 2 Short

 Video adapter failure

 Defective video adapter

 Repeating

 Memory error

 Defective memory

 1 Long, 3 Short

 Video adapter failure

 Defective video adapter or memory

 High freq. beeps

 CPU is overheating

 CPU fan failure

 Repeating High, Low beeps

 CPU failure

 Defective processor

Standard IBM Post Beep Codes:

Beep Code

What it means

Possible cause

 1 Beep (No video present)

 Normal POST

 

 2 Beeps

POST Error - code shown on screen

 

0 Beeps

Defective power supply or system board

Defective power supply or system board

 Continuous Beeps

Defective power supply, system board, or keyboard

Defective power supply, system board, or keyboard

Repeating Beeps

Defective power supply or system board

Defective power supply or system board

 1 Long, 1 short Beep

 Defective system board

 Defective system board

 1 Long, 2 short Beeps

 Defective display adapter

 Defective display adapter

1 Long, 3 short Beeps

 Defective display adapter

 Defective display adapter

 3 Long Beeps

  3270 keyboard card

  3270 keyboard card