Same problem with Toshiba Satellite P55t-B5154 running Mint 17 KDE (64-bit).
Fernando's fix worked for me as well.
Ron, I think the keyboard volume control problem is separate. For the past month (since I installed Mint on this laptop) I have not had sound, so I cannot say anything about the volume controls, however, I have noticed that the Screen Brightness keyboard controls are intermittent. I believe my backlighting control is as well.
Same problem with Toshiba Satellite P55t-B5154 running Mint 17 KDE (64-bit).
Fernando's fix worked for me as well.
Ron, I think the keyboard volume control problem is separate. For the past month (since I installed Mint on this laptop) I have not had sound, so I cannot say anything about the volume controls, however, I have noticed that the Screen Brightness keyboard controls are intermittent. I believe my backlighting control is as well.
There is a Bug report here: https:/ /bugs.launchpad .net/ubuntu/ +source/ unity/+ bug/1302885
Don't know if it is related to mine, since I am running KDE, but there you go.