Editing PC speaker (section)

=== BIOS/UEFI error codes ===
{{See also|Power-on self-test#Progress and error reporting}}
The PC speaker is used during the [[power-on self-test]] (POST) sequence to indicate errors during the [[booting|boot process]]. Since it is active before the [[video card|graphics card]], it can be used to communicate "beep codes" related to problems that prevent the much more complex initialization of the graphics card to take place. For example, the [[Video BIOS]] usually cannot activate a graphics card unless working RAM is present in the system while beeping the speaker is possible with just ROM and the CPU registers. Usually, different error codes will be signalled by specific beeping patterns, such as e.g. "one beep; pause; three beeps; pause; repeat". These patterns are specific to the BIOS/UEFI manufacturer and are usually documented in the technical manual of the motherboard.