I got exactly the same problem with my Toshiba Satelite L750, recently. I have Ubuntu 12.04.2 with kernel 3.2.0-52-generic. I suspect it must have to do with updates around 2013-08-09. Before that the speaker worked reliably. I tried to revert updates or downgrade to older kernel or newer one (3.8), but nothing helped. I observed all the effects others have described:
Waking up from suspension turns speakers on again.
Headphones always work.
Alternative USB sound card always works.
Windows always works.
Speakers are disabled only when making noise, not in phases of silence. I also suspected it is promoted by overdriven sounds.
The problem exists for all users of the machine.
It appears both on KDE and GNOME and without any desktop in the Linux konsole.
I got exactly the same problem with my Toshiba Satelite L750, recently. I have Ubuntu 12.04.2 with kernel 3.2.0-52-generic. I suspect it must have to do with updates around 2013-08-09. Before that the speaker worked reliably. I tried to revert updates or downgrade to older kernel or newer one (3.8), but nothing helped. I observed all the effects others have described:
Waking up from suspension turns speakers on again.
Headphones always work.
Alternative USB sound card always works.
Windows always works.
Speakers are disabled only when making noise, not in phases of silence. I also suspected it is promoted by overdriven sounds.
The problem exists for all users of the machine.
It appears both on KDE and GNOME and without any desktop in the Linux konsole.