Lots of the makers seem to be leaving the case speaker off. My impression is that most motherboards probably have a connection for one, but the speaker is just omitted. I've seen comments that imply that some of the newer motherboards don't even have a connection.

A few machines that I've looked at that do have a speaker installed, omit the "beep codes" from the user manuals, apparently assuming that the codes don't tell you enough to be really helpful.

(Or maybe it's because they ship the same "model" with different BIOS chips - depending on price at time of build, which can change the codes?)

John