Beep codes
Whenever a recoverable error occurs during POST, the BIOS displays an error message describing the problem. The BIOS also issues a beep code (one long tone followed by two short tones) during POST if the video configuration fails (a faulty video card or no card installed) or if an external ROM module does not properly checksum to zero.
An external ROM module (for example, a video BIOS) can also issue audible errors, usually consisting of one long tone followed by a series of short tones. For more information on the beep codes issued, check the documentation for that external device.
There are several POST routines that issue a POST terminal error and shut down the system if they fail. Before shutting down the system, the
94Troubleshooting