I had this problem too. The problem was that the alsa mixer volume settings was sometimes set to zero on reboot. I don't see the connection between running on battery/using the power cord and the volume being set to zero on reboot. But there must be some weird connection.
I had this problem too. The problem was that the alsa mixer volume settings was sometimes set to zero on reboot. I don't see the connection between running on battery/using the power cord and the volume being set to zero on reboot. But there must be some weird connection.