Recently I installed ubuntu 13.04 on my Lenovo T430.
The mute button on the laptop has an LED to indicate whether the sound is muted (LED on) or not (LED off). Ubuntu's software mute does not always match up with the state of the hardware mute.
The OS mute function does not change the state of the hardware mute. If the hardware mute is on, no sound. No matter what my settings in the OS are.
The hardware mute button does change the state of OS mute, but because the OS mute does not change the hardware state, they can be mismatched.
Is there any way to sync the two so the both reflect reality? Not sure if this is a driver or firmware problem. Perhaps it's just a feature that Ubuntu doesn't support.