1 short beep - Normal POST - system is ok

2 short beeps POST Error - error code shown on screen

No beep -Power supply or system board problem

Continuous beep - Power supply, system board, or keyboard problem

Repeating short beeps - Power supply or system board problem

1 long, 1 short beep - System board problem

1 long, 2 short beeps - Display adapter problem (MDA, CGA)

1 long, 3 short beeps - Enhanced Graphics Adapter (EGA)

3 long beeps - 3270 keyboard card