Boot chime not working

[tracer1]

Boots fine. no problems with anything but chime. Did NVRAM reset ( just guessed at chime, 2 sounds & released buttons. Mute is not checked in sound preferences. 27" apple monitor with mini display port. All sounds work fine but boot chime. Any help would be appreciated.

 

[h9826790]

Did you check if the internal speaker actually working? I think you normal use the ACD's speakers but not the tower's internal speaker, right?

 

[BillyBobBongo]

Run this in terminal:

sudo nvram -d SystemAudioVolume

You can turn off the boot chime permanently via terminal, irrespective of how your volume is set. It's a long shot but maybe turning it off an on again will get it working again. The code above is to turn the boot chime back on.

The code comes from this article