If POST completes normally, the BIOS issues one short beep before passing control to the
operating system.
Table 80.
Beep Codes
Beep
Description
1
Refresh failure
2
Parity cannot be reset
3
First 64 KB memory failure
4
Timer not operational
5
Not used
6
8042 GateA20 cannot be toggled
7
Exception interrupt error
8
Display memory R/W error
9
Not used
10
CMOS Shutdown register test error
11
Invalid BIOS (e.g. POST module not found, etc.)
Error Messages and Beep Codes
121