BEEP signals When computer starts can recognize the errors

The perfect computer without errors, the small speaker which is in the motherboard issues a normal BEEP sound. When staring at the computer the BIOS program is running for the very first time. This program is stored in a small chip which is located on the motherboard. This BIOS program's main task is the Post(POST - Power On Self Test) activity.

BIOS program is tested spontaneous.
Test computer main memory.
Identification of BUS Lines which are used for data transfers from Motherboard.
Appear the basic screen.
Boot the computer.
Build the environment to run the OS.

If any error occurs during the above process, BEEP signals are sent out. We can identify the error device such as RAM, Processor, etc by hearing the BEEP.

In IBM computer

a short BEEP ~ system error
a short BEEP twice ~ POST/ CMOS error: this error is shown as an error code on the monitor screen. So, we can identify what will be the error.
100 to 199 ~ System boards
200 to 299 ~ Memory
300 to 399 ~ Keyboard
400 to 499 ~ Monochrome display
700 to 799 ~ Math coprocessor
900 to 999 ~ Parallel printer port
1000 to 1099 ~ Alternate printer adapter
1100 to 1299 ~ Asynchronous communication device, adapter or port
1300 to 1399 ~ Game port
1400 to 1499 ~ Color/graphics printer
1500 to 1599 ~ Synchronous communication device, adapter or port
1800 to 1899 ~ Expansion unit (XT)
2000 to 2199 ~ Bisynchronous communication adapter
2400 to 2599 ~ EGA system board video (MCA)
3000 to 3199 ~ LAN adapter
4800 to 4999 ~ internal modem
7000 to 7099 ~ Phoenix BIOS chips
7300 to 7399 ~ 3.5inch disk drive
8900 to 8999 ~ MIDI adapter
11200 to 11299 ~ SCSI adapter
no BEEP ~ Power Unit or Motherboard
Nonstop BEEP ~ Power Unit, keyboard or Motherboard
Alternate short BEEP ~ Memory
A long BEEP and a Short BEEP ~ Motherboard
A long BEEP and a Short BEEP twice ~ Display adapter
A long BEEP and a Short BEEP thrice ~ graphics adapter
long BEEP thrice ~ keyboard
Alternate high and low BEEP ~ processor is overheat